$TITLE(ROM BIOS FOR IBM PERSONAL COMPUTER) ;------------------------ ; EQUATES ;------------------------ PORT_A EQU 60H ;8255 PORT A ADDR PORT_B EQU 61H ;8255 PORT B ADDR PORT_C EQU 62H ;8255 PORT C ADDR CMD_PORT EQU 63H INTA00 EQU 20H ;8259 PORT INTA01 EQU 21H ;8259 PORT EOI EQU 20H TIMER EQU 40H TIM_CTL EQU 43H ;8253 TIMER CONTROL PORT ADDR TIMER0 EQU 40H ;8253 TIMER/CNTER 0 PORT ADDR TMINT EQU 01 ;TIMER 0 INTR RECVD MASK DMA08 EQU 08 ;DMA STATUS REG PORT ADDR DMA EQU 00 ;DMA CHANNEL 0 ADDRESS REG PORT ADDR MAX_PERIOD EQU 540H MIN_PERIOD EQU 410H KBD_IN EQU 60H ;KEYBOARD DATA IN ADDR PORT KBDINT EQU 02 ;KEYBOARD INTR MASK KB_DATA EQU 60H ; KEYBOARD SCAN CODE PORT KB_CTL EQU 61H ; CONTROL BITS FOR KEYBOARD SENSE DATA ;---------------------------------- ; 8088 INTERRUPT LOCATIONS ;---------------------------------- ABS0 SEGMENT AT 0 STG_LOC0 LABEL BYTE ORG 2*4 NMI_PTR LABEL WORD ORG 5*4 INT5_PTR LABEL WORD ORG 8*4 INT_ADDR LABEL WORD INT_PTR LABEL DWORD ORG 10H*4 VIDEO_INT LABEL WORD ORG 1DH*4 PARM_PTR LABEL DWORD ; POINTER TO VIDEO PARMS ORG 01EH*4 ; INTERRUPT 1EH DISK_POINTER LABEL DWORD ORG 01FH*4 ; LOCATION OF POINTER EXT_PTR LABEL DWORD ; POINTER TO EXTENSION ORG 7C00H BOOT_LOCN LABEL FAR ABS0 ENDS ;---------------------- ; STACK -- USED DURING INITIALIZATION ONLY ;---------------------- STACK SEGMENT AT 30H DW 128 DUP(?) TOS LABEL WORD STACK ENDS ;-------------------------------------------- ; ROM BIOS DATA AREAS ;-------------------------------------------- DATA SEGMENT AT 40H RS232_BASE DW 4 DUP(?) ; ADDRESSES OF RS232 ADAPTERS PRINTER_BASE DW 4 DUP(?) ; ADDRESSES OF PRINTERS EQUIP_FLAG DW ? ; INSTALLED HARDWARE MFG_TST DB ? ; INITIALIZATION FLAG MEMORY_SIZE DW ? ; MEMORY SIZE IN K BYTES IO_RAM_SIZE DW ? ; MEMORY IN I/O CHANNEL ;-------------------------------------------- ; KEYBOARD DATA AREAS ;-------------------------------------------- KB_FLAG DB ? ;------ SHIFT FLAG EQUATES WITHIN KB_FLAG INS_STATE EQU 80H ; INSERT STATE IS ACTIVE CAPS_STATE EQU 40H ; CAPS LOCK STATE HAS BEEN TOGGLED NUM_STATE EQU 20H ; NUM LOCK STATE HAS BEEN TOGGLED SCROLL_STATE EQU 10H ; SCROLL LOCK STATE HAS BEEN TOGGLED ALT_SHIFT EQU 08H ; ALTERNATE SHIFT KEY DEPRESSED CTL_SHIFT EQU 04H ; CONTROL SHIFT KEY DEPRESSED LEFT_SHIFT EQU 02H ; LEFT SHIFT KEY DEPRESSED RIGHT_SHIFT EQU 01H ; RIGHT SHIFT KEY DEPRESSED KB_FLAG_1 DB ? ; SECOND BYTE OF KEYBOARD STATUS INS_SHIFT EQU 80H ; INSERT KEY IS DEPRESSED CAPS_SHIFT EQU 40H ; CAPS LOCK KEY IS DEPRESSED NUM_SHIFT EQU 20H ; NUM LOCK KEY IS DEPRESSED SCROLL_SHIFT EQU 10H ; SCROLL LOCK KEY IS DEPRESSED HOLD_STATE EQU 08H ; SUSPEND KEY HAS BEEN TOGGLED ALT_INPUT DB ? ; STORAGE FOR ALTERNATE KEYPAD ENTRY BUFFER_HEAD DW ? ; POINTER TO HEAD OF KEYBOARD BUFFER BUFFER_TAIL DW ? ; POINTER TO TAIL OF KEYBOARD BUFFER KB_BUFFER DW 16 DUP(?) ; ROOM FOR 15 ENTRIES KB_BUFFER_END LABEL WORD ;------ HEAD = TAIL INDICATES THAT THE BUFFER IS EMPTY NUM_KEY EQU 69 ; SCAN CODE FOR NUMBER LOCK SCROLL_KEY EQU 70 ; SCROLL LOCK KEY ALT_KEY EQU 56 ; ALTERNATE SHIFT KEY SCAN CODE CTL_KEY EQU 29 ; SCAN CODE FOR CONTROL KEY CAPS_KEY EQU 58 ; SCAN CODE FOR SHIFT LOCK LEFT_KEY EQU 42 ; SCAN CODE FOR LEFT SHIFT RIGHT_KEY EQU 54 ; SCAN CODE FOR RIGHT SHIFT INS_KEY EQU 82 ; SCAN CODE FOR INSERT KEY DEL_KEY EQU 83 ; SCAN CODE FOR DELETE KEY ;-------------------------------------------- ; DISKETTE DATA AREAS ;-------------------------------------------- SEEK_STATUS DB ? ; DRIVE RECALIBRATION STATUS ; BIT 3-0 = DRIVE 3-0 NEEDS RECAL BEFORE ; NEXT SEEK IF BIT IS = 0 INT_FLAG EQU 080H ; INTERRUPT OCCURRENCE FLAG MOTOR_STATUS DB ? ; MOTOR STATUS ; BIT 3-0 = DRIVE 3-0 IS CURRENTLY RUNNING ; BIT 7 = CURRENT OPERATION IS A WRITE, REQUIRES DELAY MOTOR_COUNT DB ? ;TIME OUT COUNTER FOR DRIVE TURN OFF MOTOR_WAIT EQU 37 ;TWO SECONDS OF COUNTS FOR MOTOR TURN OFF ; DISKETTE_STATUS DB ? ; SINGLE BYTE OF RETURN CODE INFO FOR STATUS TIME_OUT EQU 80H ; ATTACHMENT FAILED TO RESPOND BAD_SEEK EQU 40H ; SEEK OPERATION FAILED BAD_NEC EQU 20H ; NEC CONTROLLER HAS FAILED BAD_CRC EQU 10H ; BAD CRC ON DISKETTE READ DMA_BOUNDARY EQU 09H ; ATTEMPT TO DMA ACROSS 64K BOUNDARY BAD_DMA EQU 08H ; DMA OVERRUN ON OPERATION RECORD_NOT_FND EQU 04H ; REQUESTED SECTOR NOT FOUND WRITE_PROTECT EQU 03H ; WRITE ATTEMPTED ON WRITE PROT DISK BAD_ADDR_MARK EQU 02H ; ADDRESS MARK NOT FOUND BAD_CMD EQU 01H ; BAD COMMAND PASSED TO DISKETTE I/O NEC_STATUS DB 7 DUP(?) ; STATUS BYTES FROM NEC ;-------------------------------------------- ; VIDEO DISPLAY DATA AREA ;-------------------------------------------- CRT_MODE DB ? ; CURRENT CRT MODE CRT_COLS DW ? ; NUMBER OF COLUMNS ON SCREEN CRT_LEN DW ? ; LENGTH OF REGEN IN BYTES CRT_START DW ? ; STARTING ADDRESS IN REGEN BUFFER CURSOR_POSN DW 8 DUP(?) ; CURSOR FOR EACH OF UP TO 8 PAGES CURSOR_MODE DW ? ; CURRENT CURSOR MODE SETTING ACTIVE_PAGE DB ? ; CURRENT PAGE BEING DISPLAYED ADDR_6845 DW ? ; BASE ADDRESS FOR ACTIVE DISPLAY CARD CRT_MODE_SET DB ? ; CURRENT SETTING OF THE 3X8 REGISTER CRT_PALLETTE DB ? ; CURRENT PALLETTE SETTING COLOR CARD ;-------------------------------------------- ; CASSETTE DATA AREA ;-------------------------------------------- EDGE_CNT DW ? ;TIME COUNT AT DATA EDGE CRC_REG DW ? ;CRC REGISTER LAST_VAL DB ? ;LAST INPUT VALUE ;-------------------------------------------- ; TIMER DATA AREA ;-------------------------------------------- TIMER_LOW DW ? ; LOW WORD OF TIMER COUNT TIMER_HIGH DW ? ; HIGH WORD OF TIMER COUNT TIMER_OFL DB ? ; TIMER HAS ROLLED OVER SINCE LAST READ ;COUNTS_SEC EQU 18 ;COUNTS_MIN EQU 1092 ;COUNTS_HOUR EQU 65543 ;COUNTS_DAY EQU 1573040 = 1800B0H ;-------------------------------------------- ; SYSTEM DATA AREA ;-------------------------------------------- BIOS_BREAK DB ? ; BIT 7 = 1 IF BREAK KEY HAS BEEN DEPRESSED RESET_FLAG DW ? ; WORD = 1234H IF KEYBOARD RESET UNDERWAY DATA ENDS ;-------------------------------------------- ; EXTRA DATA AREA ;-------------------------------------------- XXDATA SEGMENT AT 50H STATUS_BYTE DB ? XXDATA ENDS ;-------------------------------------------- ; VIDEO DISPLAY BUFFER ;-------------------------------------------- VIDEO_RAM SEGMENT AT 0B800H REGEN LABEL BYTE REGENW LABEL WORD DB 16384 DUP(?) VIDEO_RAM ENDS ;-------------------------------------------- ; ROM RESIDENT CODE ;-------------------------------------------- CODE SEGMENT AT 0F000H DB 57344 DUP(?) ; FILL LOWEST 56K DB '5700051 COPR. IBM 1981' ; COPYRIGHT NOTICE ;-------------------------------------------- ; INITIAL RELIABILITY TESTS -- PHASE 1 ;-------------------------------------------- ASSUME CS:CODE,SS:CODE,ES:ABS0,DS:DATA ;-------------------------------------------- ; DATA DEFINITIONS ;-------------------------------------------- C1 DW C11 ; RETURN ADDRESS C2 DW C24 ; RETURN ADDRESS FOR DUMMY STACK ;-------------------------------------------- ; THIS SUBROUTINE PERFORMS A READ/WRITE STORAGE TEST ON A 16K BLOCK ; OF STORAGE. ;ENTRY REQUIREMENTS: ; ES = ADDRESS OF STORAGE SEGMENT BEING TESTED ; DS = ADDRESS OF STORAGE SEGMENT BEING TESTED ; WHEN ENTERING AT STGTST_CNT, CX MUST BE LOADED WITH THE BYTE COUNT. ;EXIT PARAMETERS: ; ZERO FLAG = 0 IF STORAGE ERROR (DATA COMPARE OR PARITY CHECK. AL=0 ; DENOTES A PARITY CHECK. ELSE AL=XOR'ED BIT PATTERN OF THE ; EXPECTED DATA PATTERN VS THE ACTUAL DATA READ. ; AX,BX,CX,DX,DI, AND SI ARE ALL DESTROYED. ;-------------------------------------------- STGTST PROC NEAR MOV CX,04000H ;SETUP CNT TO TEST A 16K BLK STGTST_CNT: CLD ;SET DIR FLAG TO INCREMENT MOV BX,CX ;SAVE BYTE CNT (4K FOR VIDEO OR 16K) MOV AX,0FFFFH ;GET DATA PATTERN TO WRITE MOV DX,0AA55H ;SETUP OTHER DATA PATTERNS TO USE SUB DI,DI ;DI = OFFSET 0 RELATIVE TO ES REG REP STOSB ;WRITE STORAGE LOCATIONS C3: ; STG01 DEC DI ;POINT TO LAST BYTE JUST WRITTEN STD ;SET DIR FLAG TO GO BACKWARDS C4: MOV SI,DI MOV CX,BX ;SETUP BYTE CNT C5: LODSB ;READ CHAR FROM STORAGE XOR AL,AH ;DATA READ AS EXPECTED? JNE C7 ;NO - GO TO ERROR ROUTINE IN AL,PORT_C ;DID A PARITY ERROR OCCUR? AND AL,0C0H MOV AL,0 ;AL=0 DATA COMPARE OK JNZ C7 CMP AH,0 ;READING ZERO PATTERN? JE C6 ;CONTINUE READING TILL END MOV AL,DL ;GET NEXT DATA PATTERN TO WRITE STOSB ;WRITE IN BYTE LOC WE JUST READ C6: ; WRITE_NO_MORE LOOP C5 ;CONTINUE TILL 16K/4K BLOCK TESTED CMP AH,0 ;ZERO PATTERN WRITTEN TO STG JE C7 ;YES - RETURN TO CALLER MOV AH,AL ;SETUP TO NEW VALUE TO COMPARE XCHG DH,DL ;MOVE ZERO DATA PATTERN TO DL CLD ;SET DIR FLAG TO GO FORWARD INC DI ;SET POINTER TO BEG LOCATION JZ C4 ;READ/WRITE FORWARD IN STG DEC DI MOV DX,1 ;SETUP 01 AND 00 PATTERNS JMP SHORT C3 ;READ/WRITE BACKWARD IN STG C7: RET STGTST ENDP ;-------------------------------------------- ;TEST.01 ; 8088 PROCESSOR TEST ;DESCRIPTION ; VERIFY 8088 FLAGS, REGISTERS AND CONDITIONAL JUMPS ;-------------------------------------------- RESET LABEL NEAR START: CLI ;DISABLE INTERRUPTS MOV AH,0D5H ;SET SF, CF, ZF, AND AF FLAGS ON SAHF JNC ERR01 ;GO TO ERR ROUTINE IF CF NOT SET JNZ ERR01 ;GO TO ERR ROUTINE IF ZF NOT SET JNP ERR01 ;GO TO ERR ROUTINE IF PF NOT SET JNS ERR01 ;GO TO ERR ROUTINE IF SF NOT SET LAHF ;LOAD FLAG IMAGE TO AH MOV CL,5 ;LOAD CNT REG WITH SHIFT CNT SHR AH,CL ;SHIFT AF INTO CARRY BIT POS JNC ERR01 ;SO TO ERR ROUTINE IF AF NOT SET MOV AL,40H ;SET THE OF FLAG ON SHL AL,1 ;SETUP FOR TESTING JNO ERR01 ;GO TO ERR ROUTINE IF OF NOT SET XOR AH,AH ;SET AH = 0 SAHF ;CLEAR SF, CF, ZF, AND PF JC ERR01 ;GO TO ERR ROUTINE IF CF ON JZ ERR01 ;GO TO ERR ROUTINE IF ZF ON JS ERR01 ;GO TO ERR ROUTINE IF SF ON JP ERR01 ;GO TO ERR ROUTINE IF PF ON LAHF ;LOAD FLAG IMAGE TO AH MOV CL,5 ;LOAD CNT REG WITH SHIFT CNT SHR AH,CL ;SHIFT AH INTO CARRY BIT POS JC ERR01 ;GO TO ERR ROUTINE IF ON SHL AH,1 ;CHECK THAT OF IS CLEAR JO ERR01 ;GO TO ERR ROUTINE IF ON ; READ/WRITE THE 8088 GENERAL AND SEGMENTATION REGISTERS ; WITH ALL ONE'S AND ZEROES'S. MOV AX,0FFFFH ;SETUP ONE'S PATTERN IN AX STC C8: MOV DS,AX ;WRITE PATTERN TO ALL REGS MOV BX,DS MOV ES,BX MOV CX,ES MOV SS,CX MOV DX,SS MOV SP,DX MOV BP,SP MOV SI,BP MOV DI,SI JNC C9 ; TST1A XOR AX,DI ;PATTERN MAKE IT THRU ALL REGS JNZ ERR01 ;NO - GO TO ERR ROUTINE CLC JNC C8 C9: ; TST1A OR AX,DI ;ZERO PATTERN MAKE IT THRU? JZ C10 ;YES - GO TO NEXT TEST ERR01: HLT ;HALT SYSTEM ;-------------------------------------------- ; TEST.02 ; ROS CHECKSUM TEST 1 ;DESCRIPTION ; A CHECKSUM IS DONE FOR THE 8K ROS MODULE CONTAINING POD AND BIOS. ;-------------------------------------------- C10: MOV AL,0 ;DISABLE NMI INTERRUPTS OUT 0A0H,AL OUT 83H,AL ;INITIALIZE DMA PAGE REG MOV AL,99H ;SET 8255 A,C-INPUT,B-OUTPUT OUT CMD_PORT,AL ;WRITE 8255 CMD/MODE REG MOV AL,0FCH ;DISABLE PARITY CHECKERS AND OUT PORT_B,AL ; GATE SNS SWS,CASS MOTOR OFF SUB AL,AL ; MOV DX,3D8H OUT DX,AL ;DISABLE COLOR VIDEO INC AL MOV DX,3B8H OUT DX,AL ;DISABLE B/W VIDEO,EN HIGH RES MOV AX,CODE ;SETUP SS SEG REG MOV SS,AX MOV BX,0E000H ;SETUP STARTING ROS ADDR MOV SP,OFFSET C1 ;SETUP RETURN ADDRESS JMP ROS_CHECKSUM C11: JNE ERR01 ;HALT SYSTEM IF ERROR ;-------------------------------------------- ;TEST.03 ; 8237 DMA INITIALIZATION CHANNEL REGISTER TEST ;DESCRIPTION ; DISABLE THE 8237 DMA CONTROLLER. VERIFY THAT TIMER 1 FUNCTIONS OK. ; WRITE/READ THE CURRENT ADDRESS AND WORD COUNT REGISTERS FOR ALL ; CHANNELS INITIALIZE AND START DMA FOR MEMORY REFRESH. ;------------------------------------------ ; DISABLE DMA CONTROLLER MOV AL,04 ;DISABLE DMA CONTROLLER OUT DMA08,AL ; VERIFY THAT TIMER 1 FUNCTIONS OK MOV AL,54H ;SEL TIMER 1,LSB,MODE 2 OUT TIMER+3,AL SUB CX,CX ; MOV BL,CL MOV AL,CL ;SET INITIAL TIMER CNT TO 0 OUT TIMER+1,AL C12: ; TIMER1_BITS_ON MOV AL,40H ;LATCH TIMER 1 COUNT OUT TIMER+3,AL IN AL,TIMER+1 ;READ TIMER 1 COUNT OR BL,AL ;ALL BITS ON IN TIMER CMP BL,0FFH ;YES - SEE IF ALL BITS GO OFF JE C13 ; TIMER1_BITS_OFF LOOP C12 ; TIMER1_BITS_ON JMP SHORT ERR01 ;TIMER 1 FAILURE, HALT SYS C13: ; TIMER1_BITS_OFF MOV AL,BL ;SET TIMER 1 CNT SUB CX,CX OUT TIMER+1,AL C14: ; TIMER_LOOP MOV AL,40H ;LATCH TIMER 1 COUNT OUT TIMER+3,AL IN AL,TIMER+1 ;READ TIMER 1 COUNT AND BL,AL JZ C15 ; WRAP_DMA_REG LOOP C14 ; TIMER_LOOP JMP SHORT ERR01 ; INITIALIZE TIMER 1 TO REFRESH MEMORY C15: ; WRAP_DMA_REG MOV AL,54H ;SEL TIM 1, LSB, MODE 2 OUT TIMER+3,AL ;WRITE TIMER MODE REG MOV AL,18 ;SETUP DIVISOR FOR REFRESH OUT TIMER+1,AL ;WRITE TIMER 1 CNT REG OUT DMA+0DH,AL ;SEND MASTER CLEAR TO DMA ; WRAP DMA CHANNELS ADDRESS AND COUNT REGISTERS MOV AL,0FFH ;WRITE PATTERN FFH TO ALL REGS C16: MOV BL,AL ;SAVE PATTERN FOR COMPARE MOV BH,AL MOV CX,8 ;SETUP LOOP CNT MOV DX,DMA ;SETUP I/O PORT ADDR OF REG C17: OUT DX,AL ;WRITE PATTERN TO REG, LSB OUT DX,AL ;MSB OF 16 BIT REG MOV AX,0101H ;AX TO ANOTHER PAT BEFORE RD IN AL,DX ;READ 16-BIT DMA CH REG, LSB MOV AH,AL ;SAVE LSB OF 16-BIT REG IN AL,DX ;READ MSB OF DMA CH REG CMP BX,AX ;PATTERN READ AS WRITTEN? JE C18 ;YES - CHECK NEXT REG JMP ERR01 ;NO - HALT THE SYSTEM C18: ; NXT_DMA_CH INC DX ;SET I/O PORT TO NEXT CH REG LOOP C17 ;WRITE PATTERN TO NEXT REG NOT AL ;SET PATTERN TO ZERO JZ C16 ;WRITE TO CHANNEL REGS ; INITIALIZE AND START DMA FOR MEMORY REFRESH. MOV AL,0FFH ;SET CNT OF 64K FOR RAM REFRESH OUT DMA+1,AL OUT DMA+1,AL MOV AL,058H ;SET DMA MODE,CH 0,READ,AUTOINT OUT DMA+0BH,AL ;WRITE DMA MODE REG MOV AL,0 ;ENABLE DMA CONTROLLER OUT DMA+8,AL ;SETUP DMA COMMAND REG OUT DMA+10,AL ;ENABLE CHANNEL 0 FOR REFRESH MOV AL,41H ;SET MODE FOR CHANNEL 1 OUT DMA+0BH,AL MOV AL,42H ;SET MODE FOR CHANNEL 2 OUT DMA+0BH,AL ; MOV AL,43H ;SET MODE FOR CHANNEL 3 OUT DMA+0BH,AL ;-------------------------------------------- ;TEST.04 ; BASE 16K READ/WRITE STORAGE TEST ; ;DESCRIPTION ; WRITE/READ/VERIFY DATA PATTERNS FF,55,AA,01, AND 00 TO 1ST 16K OF ; STORAGE. VERIFY STORAGE ADDRESSABILITY. ; INITIALIZE THE 8259 INTERRUPT CONTROLLER CHIP FOR CHECKING ; MANUFACTURING TEST 2 MODE. ;-------------------------------------------- ; DETERMINE MEMORY SIZE AND FILL MEMORY WITH DATA MOV AX,DATA ;POINT DS TO DATA SEG MOV DS,AX ; MOV BX,RESET_FLAG ;SAVE RESET_FLAG IN BX SUB AX,AX ;SET ES AND DS TO 0 MOV ES,AX ;SETUP ES SEGMENT REG MOV DS,AX SUB DI,DI IN AL,PORT_A ;DETERMINE BASE RAM SIZE AND AL,0CH ;ISOLATE RAM SIZE SWS ADD AL,4 ; CALCULATE MEMORY SIZE MOV CL,12 SHL AX,CL MOV CX,AX MOV AH,AL CLD ;SET DIR FLAG TO INCR C19: STOSB ;FILL BASE RAM WITH DATA LOOP C19 ; LOOP TIL ALL ZERO ; DETERMINE IO CHANNEL RAM SIZE IN AL,PORT_C AND AL,0FH JZ C21 MOV DX,1000H ; SEGMENT FOR I/O RAM MOV AH,AL MOV AL,0 C20: ; FILL_IO MOV ES,DX MOV CX,8000H ; FILL 32K BYTES SUB DI,DI REP STOSB ADD DX,800H ; NEXT SEGMENT VALUE DEC AH JNZ C20 ; FILL_IO ;-------------------------------------------- ; INITIALIZE THE 8259 INTERRUPT CONTROLLER CHIP ;-------------------------------------------- C21: MOV AL,13H ;ICW1 - EDGE, SNGL, ICW4 OUT INTA00,AL MOV AL,8 ;SETUP ICW2 - INT TYPE 8 (8-F) OUT INTA01,AL MOV AL,9 ;SETUP ICW4 - BUFFRD,8086 MODE OUT INTA01,AL SUB AX,AX ;POINT DS AND ES TO BEGIN MOV ES,AX ; OF R/W STORAGE MOV SI,DATA ;POINT DS TO DATA SEG MOV DS,SI ; MOV RESET_FLAG,BX ;RESTORE RESET_FLAG CMP RESET_FLAG,1234H ;RESET_FLAG SET? JE C25 ;YES - SKIP STG TEST MOV DS,AX ;POINT DS TO 1ST 16K OF STG ;-------------------------------------------- ; CHECK FOR MANUFACTURING TEST 2 TO LOAD TEST PROGRAMS FROM KEYBOARD. ;-------------------------------------------- MOV SP,3FF0H ; ESTABLISH TEMPORARY STACK MOV SS,AX MOV DI,AX MOV BX,24H MOV WORD PTR [BX],OFFSET D11 ;SET UP KB INTERRUPT INC BX INC BX MOV [BX],CS CALL KBD_RESET ; READ IN KB RESET CODE TO BL CMP BL,065H ; IS THIS MANUFACTURING TEST 2? JNZ C23 ; JUMP IF NOT MAN. TEST MOV DL,255 ; READ IN TEST PROGRAM C22: CALL SP_TEST MOV AL,BL STOSB DEC DL JNZ C22 ; JUMP IF NOT DONE RET INT 3EH ;SET INTERUPT TYPE 62 ADDRESS F8H C23: ;CONTINUE IN NORMAL MODE PUSH CS ; PUT SS BACK POP SS CLI ; MOV SP,OFFSET C2 ;SETUP RETURN ADDRESS JMP STGTST ;GO TO RD/WRT STG SUBROUTINE C24: JE C25 ;GO TO NEXT TEST IF OK JMP ERR01 ; SETUP STACK SEG AND SP C25: MOV AX,STACK ; GET STACK VALUE MOV SS,AX ; SET THE STACK UP MOV SP,OFFSET TOS ; STACK IS READY TO GO ; SETUP THE NMI INTERRUPT VECTOR POINTER MOV ES:NMI_PTR,OFFSET NMI_INT MOV ES:NMI_PTR+2,CODE JMP TST6 ;GO TO NEXT TEST ROS_CHECKSUM PROC NEAR ; NEXT_ROS_MODULE MOV CX,8192 ;NUMBER OF BYTES TO ADD XOR AL,AL C26: ADD AL,CS:[BX] ; INC BX ;POINT TO NEXT BYTE LOOP C26 ;ADD ALL BYTES IN ROS MODULE OR AL,AL ;SUM = 0? RET ROS_CHECKSUM ENDP ;-------------------------------------- ; INITIAL RELIABILITY TEST -- PHASE 2 ;--------------------------------------- ASSUME CS:CODE,ES:ABS0 D1 DB 'PARITY CHECK 2' D1L EQU $-D1 D2 DB 'PARITY CHECK 1' D2L EQU $-D2 ;--------------------------------------------- ; TEST.06 ; 8259 INTERRUPT CONTROLLER TEST ;DESCRIPTION ; READ/WRITE THE INTERRUPT MASK REGISTER (IMR) WITH ALL ONES AND ZEROES ; ENABLE SYSTEM INTERRUPTS. MASK DEVICE INTERRUPTS OFF. CHECK FOR ; HOT INTERRUPTS (UNEXPECTED). ;-------------------------------------------- TST6: SUB AX,AX ;SET UP ES REG MOV ES,AX ;------ SET UP THE INTERRUPT 5 POINTER TO A DUMMY MOV ES:INT5_PTR,OFFSET PRINT_SCREEN ;PRINT SCREEN MOV ES:INT5_PTR+2,CODE ; ; TEST THE IMR REGISTER CLI ;DISABLE INTERRUPTS MOV AL,0 OUT INTA01,AL IN AL,INTA01 ;READ IMR OR AL,AL ;IMR = 0? JNZ D6 ;GO TO ERR ROUTINE IF NOT 0 MOV AL,0FFH ;DISABLE DEVICE INTERRUPTS OUT INTA01,AL ;WRITE TO IMR IN AL,INTA01 ;READ IMR ADD AL,1 ;ALL IMR BITS ON? JNZ D6 ;NO - GO TO ERR ROUTINE ; CHECK FOR HOT INTERRUPTS CLD ;SET DIR FLAG TO GO FORWARD MOV CX,8 ;SETUP TEMP INT RTNE IN PRT TBL MOV DI,OFFSET INT_PTR ;GET ADDRESS OF INT PROC TABLE D3: ; VECTBL0 MOV AX,OFFSET D11 ;MOVE ADDR OF INTR PROC TO TBL STOSW MOV AX,CODE ;GET ADDR OF INTR PROC SEG STOSW ADD BX,4 ;SET BX TO POINT TO NEXT VAL LOOP D3 ; VECTBL0 ; INTERRUPTS ARE MASKED OFF. CHECK THAT NO INTERRUPTS OCCUR XOR AH,AH ;CLEAR AH REG STI ;ENABLE EXTERNAL INTERRUPTS SUB CX,CX ;WAIT 1 SEC FOR ANY INTRS THAT D4: LOOP D4 ;MIGHT OCCUR D5: LOOP D5 OR AH,AH ;DID ANY INTERRUPTS OCCUR? JZ D7 ;NO - GO TO NEXT TEST D6: MOV DX,101H ;BEEP SPEAKER IF ERROR CALL ERR_BEEP ;GO TO BEEP SUBROUTINE CLI HLT ;HALT THE SYSTEM ;-------------------------------------------- ;TEST.7 ; 8253 TIMER CHECKOUT ;DESCRIPTION ; VERIFY THAT THE SYSTEM TIMER (0) DOESN'T COUNT TOO FAST NOR TOO ; SLOW. ;-------------------------------------------- D7: MOV AH,0 ;RESET TIMER INTR RECVD FLAG XOR CH,CH ;CLEAR THE CH REG MOV AL,0FEH ;MASK ALL INTRS EXCEPT LVL 0 OUT INTA01,AL ;WRITE THE 8259 IMR MOV AL,00010000B ;SEL TIM 0, LSB, MODE 0, BINARY OUT TIM_CTL,AL ;WRITE TIMER CONTROL MODE REG MOV CL,16H ;SET PGM LOOP CNT MOV AL,CL ;SET TIMER 0 CNT REG OUT TIMER0,AL ;WRITE TIMER 0 CNT REG D8: TEST AH,0FFH ;DID TIMER 0 INTERRUPT OCCUR? JNZ D9 ; YES - CHECK TIMER OP FOR SLOW TIME LOOP D8 ;WAIT FOR INTR FOR SPECIFIED TIME JMP D6 ;TIMER 0 INTR DIDN'T OCCUR - ERR D9: MOV CL,18 ;SET PGM LOOP CNT MOV AL,0FFH ;WRITE TIMER 0 CNT REG OUT TIMER0,AL MOV AH,0 ;RESET INTR RECEIVED FLAG MOV AL,0FEH ;REENABLE TIMER 0 INTERRUPTS OUT INTA01,AL D10: TEST AH,0FFH ;DID TIMER 0 INTERRUPT OCCUR? JNZ D6 ;YES - TIMER CNTING TOO FAST, ERR LOOP D10 ;WAIT FOR INTR FOR SPECIFIED TIME JMP TST8 ;GO TO NEXT TEST ROUTINE ;-------------------------------------------- ; TEMPORARY INTERRUPT SERVICE ROUTINE ;-------------------------------------------- D11 PROC NEAR MOV AH,1 PUSH AX ;SAVE REG AX CONTENTS MOV AL,0FFH ;MASK ALL INTERRUPTS OFF OUT INTA01,AL MOV AL,EOI OUT INTA00,AL POP AX ;RESTORE REG AX CONTENTS IRET D11 ENDP NMI_INT PROC NEAR PUSH AX ;SAVE ORIG CONTENTS OF AX IN AL,PORT_C TEST AL,40H ;IO CH PARITY CHECK? JZ D12 ;YES - FLAG IS SET TO 0 MOV SI,OFFSET D1 ;ADDR OF ERROR MSG MOV CX,D1L ;MSG LENGTH JMP SHORT D13 ;DISPLAY ERROR MSG D12: TEST AL,80H ;PLANAR RAM P-CHECK? JZ D14 ;NO - AUX INT MOV SI,OFFSET D2 ;ADDR OF ERROR MSG MOV CX,D2L ;MSG LENGTH D13: MOV AX,0 ;INIT AND SET MODE FOR VIDEO INT 10H ;CALL VIDEO_IO PROCEDURE CALL P_MSG ;PRINT ERROR MSG CLI HLT ;HALT SYSTEM D14: POP AX ;RESTORE ORIG CONTENTS OF AX IRET NMI_INT ENDP ;------------------------------------- ; INITIAL RELIABILITY TEST -- PHASE 3 ;-------------------------------------- ASSUME CS:CODE,DS:DATA E1 DB ' 201' E1L EQU $-E1 ; ESTABLISH BIOS SUBROUTINE CALL INTERRUPT VECTORS TST8: CLD ;SET DIR FLAG TO GO FORWARD MOV DI,OFFSET VIDEO_INT ;SETUP ADDR TO INTR AREA PUSH CS POP DS ;SETUP ADDR OF VECTOR TABLE MOV SI,0FF13H ; OFFSET VECTOR_TABLE+32 MOV CX,20H REP MOVSW ;MOVE VECTOR TABLE TO RAM ; SETUP TIMER 0 TO MODE 3 MOV AL,0FFH ;DISABLE ALL DEVICE INTERRUPTS OUT INTA01,AL MOV AL,36H ;SEL TIM 0,LSB,MSB,MODE 3 OUT TIMER+3,AL ;WRITE TIMER MODE PEG MOV AL,0 OUT TIMER,AL ;WRITE LSB TO TIMER 0 REG OUT TIMER,AL ;WRITE MSB TO TIMER 0 REG ; SETUP TIMER 0 TO BLINK LED IF MANUFACTURING TEST MODE ASSUME DS:DATA MOV AX,DATA ;POINT DS TO DATA SEG MOV DS,AX CALL KBD_RESET ;SEND SOFTWARE RESET TO KEYBRD CMP BL,0AAH ;SCAN CODE 'AA' RETURNED? JE E3 ;YES - CONTINUE (NON MFG MODE) MOV AL,3CH ;EN KBD, SET KBD CLK LINE LOW OUT PORT_B,AL ;WRITE 8255 PORT B NOP NOP IN AL,PORT_A ;WAS A BIT CLOCKED IN? AND AL,0FFH JNZ E2 ;YES - CONTINUE (NON MFG MODE) INC MFG_TST ;ELSE SET SW FOR MFG TEST MODE MOV ES:INT_ADDR,OFFSET BLINK_INT ;SETUP TIMER INTR TO BLINK LED MOV ES:INT_ADDR+2,CODE MOV AL,0FEH ;ENABLE TIMER INTERRUPT OUT INTA01,AL E2: ; JUMPER_NOT_IN: MOV AL,0CCH ;RESET THE KEYBOARD OUT PORT_B,AL ;-------------------------------------------- ;TEST.05 ; ROS CHECKSUM II ;DESCRIPTION ; A CHECKSUM IS DONE FOR THE 4 ROS MODULES CONTAINING BASIC CODE ;-------------------------------------------- E3: MOV DL,4 ;NO. OF ROS MODULES TO CHECK MOV BX,6000H ;SETUP STARTING ROS ADDR E4: ; CHECK_ROS: CALL ROS_CHECKSUM JNE E5 ;BEEP SPEAKER IF ERROR DEC DL ;ANY MORE TO DO? JNZ E4 ;YES - CONTINUE JMP E6 ;NO - GO TO NEXT TEST E5: ; ROS_ERROR: MOV DX,101H CALL ERR_BEEP ;BEEP SPEAKER ;-------------------------------------------- ;TEST.08 ; INITIALIZE AND START CRT CONTROLLER (6845) ; TEST VIDEO READ/WRITE STORAGE. ;DESCRIPTION ; RESET THE VIDEO ENABLE SIGNAL. ; SELECT ALPHANUMERIC MODE, 40 * 25, B & W ; READ/WRITE DATA PATTERNS TO STG. CHECK STG ADDRESSABILITY. ;-------------------------------------------- E6: IN AL,PORT_A ;READ SENSE SWITCHES MOV AH,0 MOV EQUIP_FLAG,AX ;STORE SENSE SW INFO AND AL,30H ;ISOLATE VIDEO SW JNZ E7 ;VIDEO SWS SET TO 0? JMP E19 ;SKIP VIDEO TESTS FOR BURN-IN E7: ; TEST_VIDEO: XCHG AH,AL CMP AH,30H ;B/W CARD ATTACHED? JE E8 ;YES - SET MODE FOR B/W CARD INC AL ;SET COLOR MODE FOR COLOR CD CMP AH,20H ;80X25 MODE SELECTED? JNE E8 ;NO - SET MODE FOR 40X25 MOV AL,3 ;SET MODE FOR 80X25 E8: ; SET_MODE: PUSH AX ;SAVE VIDEO MODE ON STACK SUB AH,AH ;INITIALIZE TO ALPHANUMERIC INT 10H ;CALL VIDEO_IO POP AX ;RESTORE VIDEO SENSE SWS IN AH PUSH AX ; RESAVE VALUE MOV BX,0B000H ;BEG VIDEO RAM ADDR B/W CD MOV DX,3B8H ;MODE REG FOR B/W MOV CX,4096 ;RAM BYTE CNT FOR B/W CD MOV AL,1 ; SET MODE FOR B/W CARD CMP AH,30H ;B/W VIDEO CARD ATTACHED? JE E9 ;YES - GO TEST VIDEO STG MOV BX,0B800H ;BEG VIDEO RAM ADDR COLOR CD MOV DX,3D8H ;MODE REG FOR COLOR CD MOV CX,4000H ;RAM BYTE CNT FOR COLOR CD DEC AL ; SET MODE TO 0 FOR COLOR CD E9: ; TEST_VIDEO_STG: OUT DX,AL ;DISABLE VIDEO FOR COLOR CD MOV ES,BX ;POINT ES TO VIDEO RAM STG MOV AX,DATA ;POINT DS TO DATA SEGMENT MOV DS,AX CMP RESET_FLAG,1234H ;POD INITIATED BY KBD RESET? JE E10 ;YES - SKIP VIDEO RAM TEST MOV DS,BX ;POINT DS TO VIDEO RAM STG CALL STGTST_CNT ;GO TEST VIDEO R/W STG JE E10 ;STG OK - CONTINUE TESTING MOV DX,102H ;SETUP # OF BEEPS CALL ERR_BEEP ;GO BEEP SPEAKER ;-------------------------------------------- ;TEST.09 ; SETUP VIDEO DATA ON SCREEN FOR VIDEO LINE TEST. ;DESCRIPTION ; ENABLE VIDEO SIGNAL AND SET MODE. ; DISPLAY A HORIZONTAL BAR ON SCREEN. ;-------------------------------------------- E10: POP AX ;GET VIDEO SENSE SWS (AH) PUSH AX ;SAVE IT MOV AH,0 ;ENABLE VIDEO AND SET MODE INT 10H ; VIDEO MOV AX,7020H ;WRT BLANKS IN REVERSE VIDEO SUB DI,DI ;SETUP STARTING LOC MOV CX,40 ;NO. OF BLANKS TO DISPLAY CLD ;SET DIR FLAG TO INCREMENT REP STOSW ;WRITE VIDEO STORAGE ;-------------------------------------------- ;TEST.10 ; CRT INTERFACE LINES TEST ;DESCRIPTION ; SENSE ON/OFF TRANSITION OF THE VIDEO ENABLE AND HORIZONTAL ; SYNC LINES. ;-------------------------------------------- POP AX ;GET VIDEO SENSE SW INFO PUSH AX ;SAVE IT CMP AH,30H ;B/W CARD ATTACHED? MOV DX,03BAH ;SETUP ADDR OF BW STATUS PORT JE E11 ;YES - GO TEST LINES MOV DX,03DAH ;COLOR CARD IS ATTACHED E11: ; LINE_TST: MOV AH,8 E12: ; OFLOOP_CNT: SUB CX,CX E13: IN AL,DX ;READ CRT STATUS PORT AND AL,AH ;CHECK VIDEO/HORZ LINE JNZ E14 ;ITS ON - CHECK IF IT GOES OFF LOOP E13 ;LOOP TILL ON OR TIMEOUT JMP SHORT E17 ;GO PRINT ERROR MSG E14: SUB CX,CX E15: IN AL,DX ;READ CRT STATUS PORT AND AL,AH ;CHECK VIDEO/HORZ LINE JZ E16 ;ITS ON - CHECK NEXT LINE LOOP E15 ;LOOP IF OFF TILL IT GOES ON JMP SHORT E17 E16: ; NXT_LINE: MOV CL,3 ;GET NEXT BIT TO CHECK SHR AH,CL ; JNZ E12 ;GO CHECK HORIZONTAL LINE JMP SHORT E18 ;DISPLAY CURSOR ON SCREEN E17: ; CRT_ERR: MOV DX,102H CALL ERR_BEEP ;GO BEEP SPEAKER E18: ; DISPLAY_CURSOR: POP AX ;GET VIDEO SENSE SWS (AH) MOV AH,0 ;SET MODE AND DISPLAY CURSOR INT 10H ;CALL VIDEO I/O PROCEDURE ;-------------------------------------------- ;TEST.11 ; ADDITIONAL READ/WRITE STORAGE TEST ;DESCRIPTION ; WRITE/READ DATA PATTERNS TO ANY READ/WRITE STORAGE AFTER THE BASIC ; 16K. STORAGE ADDRESSABILITY IS CHECKED. ;-------------------------------------------- ASSUME DS:DATA E19: MOV AX,DATA MOV DS,AX ; DETERMINE RAM SIZE ON PLANAR BOARD MOV AH,BYTE PTR EQUIP_FLAG ;GET SENSE SWS INFO AND AH,0CH ;ISOLATE RAM SIZE SWS MOV AL,4 MUL AH ADD AL,16 ;ADD BASIC 16K MOV DX,AX ;SAVE PLANAR RAM SIZE IN DX MOV BX,AX ; AND IN BX ; DETERMINE IO CHANNEL RAM SIZE IN AL,PORT_C ;READ IO CH RAM SIZE SWS AND AL,0FH ;ISOLATE FROM OTHER BITS MOV AH,32 MUL AH MOV IO_RAM_SIZE,AX ;SAVE IO CHANNEL RAM SIZE CMP BX,40H ;PLANAR RAM SIZE = 64K? JE E20 ;YES - ADD IO CHN RAM SIZE SUB AX,AX ;NO - DON'T ADD ANY IO RAM E20: ; ADD_ID_SIZE: ADD AX,BX ;SUM TOTAL RAM SIZE MOV MEMORY_SIZE,AX ;SETUP MEMORY SIZE PARM CMP RESET_FLAG,1234H ;POD INITIATED BY KBD RESET? JE E22 ;YES - SKIP MEMORY TEST ; TEST ANY OTHER READ/WRITE STORAGE AVAILABLE MOV BX,400H MOV CX,16 E21: CMP DX,CX ;ANY MORE STG TO BE TESTED? JBE E23 ;NO - GO TO NEXT TEST MOV DS,BX ;SETUP STG ADDR IN DS AND ES MOV ES,BX ADD CX,16 ;INCREMENT STG BYTE COUNTER ADD BX,400H ;SET POINTER TO NEXT 16K BLK PUSH CX ;SAVE REGS PUSH BX PUSH DX CALL STGTST ;GO TEST A 16K BLK OF STG POP DX POP BX ;RESTORE REGS POP CX JE E21 ;CHECK IF MORE STG TO TEST ; PRINT FAILING ADDRESS AND XOR'ED PATTERN IF DATA COMPARE ERROR MOV DX,DS ;CONVERT FAILING HIGH-ORDER MOV CH,AL ;SAVE FAILING BIT PATTERN MOV AL,DH ;GET FAILING ADDR (HIGH BYTE) MOV CL,4 SHR AL,CL ;RIGHT-JUSTIFY HIGH BYTE CALL XLAT_PRINT_CODE ;CONVERT AND PRINT CODE MOV AL,DH AND AL,0FH CALL XLAT_PRINT_CODE ;CONVERT AND PRINT CODE MOV AL,CH ;GET FAILING BIT PATTERN MOV CL,4 ; AND ISOLATE LEFTMOST NIBBLE SHR AL,CL CALL XLAT_PRINT_CODE ;CONVERT AND PRINT CODE MOV AL,CH ;GET FAILING BIT PATTERN AND AND AL,0FH ; ISOLATE RIGHTMOST NIBBLE CALL XLAT_PRINT_CODE ;CONVERT AND PRINT CODE MOV SI,OFFSET E1 ;SETUP ADDRESS OF ERROR MSG MOV CX,E1L ;GET MSG BYTE COUNT CALL P_MSG ;PRINT ERROR MSG E22: ; GO_TST12: JMP TST12 ;GO TO NEXT TEST E23: ; STG_TEST_DONE: MOV AX,DATA ;POINT DS TO DATA SEGMENT MOV DS,AX ; CHG MADE 3/27/81 MOV DX,IO_RAM_SIZE ;GET IO CHANNEL RAM SIZE OR DX,DX ;SET FLAG RESULT JZ E22 ;NO IO RAM, GO TO NEXT TEST MOV CX,0 CMP BX,1000H ;HAS IO RAM BEEN TESTED JA E22 ;YES - GO TO NEXT TEST MOV BX,1000H ;SETUP BEG LOC FOR IO RAM JMP SHORT E21 ;GO TEST IO CHANNEL RAM ;-------------------------------------------- ; CONVERT AND PRINT ASCII CODE ; ; AL MUST CONTAIN NUMBER TO BE CONVERTED. ; AX AND BX DESTROYED. ;-------------------------------------------- XLAT_PRINT_CODE PROC NEAR PUSH DS ;SAVE DS VALUE PUSH CS ;POINT DS TO CODE SEG POP DS MOV BX,0E4B7H ; OFFSET ASCII_TBL-XLAT TABLE XLATB MOV AH,14 MOV BH,0 INT 10H ;CALL VIDEO_IO POP DS ;RESTORE ORIG VALUE IN DS RET XLAT_PRINT_CODE ENDP ;--------------------------------------- ; INITIAL RELIABILITY TEST -- PHASE 4 ;--------------------------------------- ASSUME CS:CODE,DS:DATA F1 DB ' 301' F1L EQU $-F1 ; KEYBOARD MESSAGE F2 DB '131' F2L EQU $-F2 ; CASSETTE MESSAGE F3 DB '601' F3L EQU $-F3 ; DISKETTE MESSAGE F4 LABEL WORD ; PRINTER SOURCE TABLE DW 3BCH DW 378H DW 278H F4E LABEL WORD ASCII_TBL DB '0123456789ABCDEF' ;-------------------------------------------- ;TEST.12 ; KEYBOARD TEST ;DESCRIPTION ; RESET THE KEYBOARD AND CHECK THAT SCAN CODE 'AA' IS RETURNED ; TO THE CPU. CHECK FOR STUCK KEYS. ;-------------------------------------------- TST12: MOV AX,DATA ;POINT DS TO DATA SEG MOV DS,AX CMP MFG_TST,1 ;MANUFACTURING TEST MODE? JE F7 ;YES - SKIP KEYBOARD TEST CALL KBD_RESET ;ISSUE SOFTWARE RESET TO KEYBRD JCXZ F6 ;PRINT ERR MSG IF NO INTERRUPT MOV AL,4DH ;ENABLE KEYBOARD OUT PORT_B,AL CMP BL,0AAH ;SCAN CODE AS EXPECTED? JNE F6 ;NO - DISPLAY ERROR MSG ; CHECK FOR STUCK KEYS MOV AL,0CCH ;CLR KBD, SET CLK LINE HIGH OUT PORT_B,AL MOV AL,4CH ;ENABLE KBD,CLK IN NEXT BYTE OUT PORT_B,AL SUB CX,CX F5: ; KBD_WAIT: LOOP F5 ;DELAY FOR A WHILE IN AL,KBD_IN ;CHECK FOR STUCK KEYS CMP AL,0 ;SCAN CODE = 0? JE F7 ;YES - CONTINUE TESTING MOV CH,AL ;SAVE SCAN CODE MOV CL,4 SHR AL,CL ;RIGHT-JUSTIFY HIGH BYTE CALL XLAT_PRINT_CODE ;CONVERT AND PRINT MOV AL,CH ;RECOVER SCAN CODE AND AL,0FH ;ISOLATE LOW ORDER BYTE CALL XLAT_PRINT_CODE ;CONVERT AND PRINT F6: MOV SI,OFFSET F1 ;GET MSG ADDR MOV CX,F1L ;GET MSG BYTE COUNT CALL P_MSG ;PRINT MSG ON SCREEN ; SETUP INTERRUPT VECTOR TABLE F7: ; SETUP_INT_TABLE: SUB AX,AX MOV ES,AX MOV CX,24*2 ;GET VECTOR CNT PUSH CS ;SETUP DS SEG REG POP DS MOV SI,0FEF3H ; OFFSET VECTOR_TABLE MOV DI,OFFSET INT_PTR CLD REP MOVSW ;-------------------------------------------- ;TEST.13 ; CASSETTE DATA WRAP TEST ;DESCRIPTION ; TURN CASSETTE MOTOR OFF. WRITE A BIT OUT TO THE CASSETTE DATA BUS. ; VERIFY THAT CASSETTE DATA READ IS WITHIN A VALID RANGE. ;-------------------------------------------- ; TURN THE CASSETTE MOTOR OFF MOV AX,DATA ;POINT DS REG TO DATA SEG MOV DS,AX MOV AL,04DH ;SET TIMER 2 SPK OUT, AND CASST OUT PORT_B,AL ;OUT BITS ON, CASSETTE MOT OFF ; WRITE A BIT MOV AL,0FFH ;DISABLE TIMER INTERRUPTS OUT INTA01,AL MOV AL,0B6H ;SEL TIM 2, LSB, MSB, MD 3 OUT TIMER+3,AL ;WRITE 8253 CMD/MODE REG MOV AX,1235 ;SET TIMER 2 CNT FOR 1000 USEC OUT TIMER+2,AL ;WRITE TIMER 2 COUNTER REG MOV AL,AH ;WRITE MSB OUT TIMER+2,AL ; READ CASSETTE INPUT IN AL,PORT_C ;READ VALUE OF CASS IN BIT AND AL,10H ;ISOLATE FROM OTHER BITS MOV LAST_VAL,AL CALL READ_HALF_BIT CALL READ_HALF_BIT JCXZ F8 ; CAS_ERR CMP BX,MAX_PERIOD JNC F8 ; CAS_ERR CMP BX,MIN_PERIOD JNC F9 ;GO TO NEXT TEST IF OK F8: ; CAS_ERR: MOV SI,OFFSET F2 ;CASSETTE WRAP FAILED MOV CX,F2L CALL P_MSG ;GO PRINT ERROR MSG ;-------------------------------------------- ;TEST.14 ; DISKETTE ATTACHMENT TEST ;DESCRIPTION ; CHECK IF IPL DISKETTE DRIVE IS ATTACHED TO SYSTEM. IF ATTACHED, ; VERIFY STATUS OF NEC FDC AFTER A RESET. ISSUE A RECAL AND SEEK ; CMD TO FDC AND CHECK STATUS. COMPLETE SYSTEM INITIALIZATION THEN ; PASS CONTROL TO THE BOOT LOADER PROGRAM. ;-------------------------------------------- F9: MOV AL,0FCH ;ENABLE TIMER AND KBD INTS OUT INTA01,AL MOV AL,BYTE PTR EQUIP_FLAG ;GET SENSE SWS INFO TEST AL,01H ;IPL DISKETTE DRIVE ATTCH? JNZ F10 ;YES - TEST DISKETTE CONTR JMP F22 ;NO - SKIP THIS TEST F10: ; DISK-TEST: MOV AL,0BCH ;ENABLE DISKETTE, KEYBOARD, OUT INTA01,AL ; AND TIMER INTERRUPTS MOV AH,0 ;RESET NEC FDC INT 13H ;VERIFY STATUS AFTER RESET TEST AH,0FFH ;STATUS OK? JNZ F13 ;NO - FDC FAILED ; TURN DRIVE 0 MOTOR ON MOV DX,03F2H ;GET ADDR OF FDC CARD MOV AL,1CH ;TURN MOTOR ON, EN DMA/INT OUT DX,AL ;WRITE FDC CONTROL REG SUB CX,CX F11: ; MOTOR_WAIT: LOOP F11 ;WAIT FOR 1 SECOND F12: ; MOTOR_WAIT1: LOOP F12 XOR DX,DX ;SELECT DRIVE 0 MOV CH,1 ;SELECT TRACK 1 MOV SEEK_STATUS,DL CALL SEEK ;RECALIBRATE DISKETTE JC F13 ;GO TO ERR SUBROUTINE IF ERR MOV CH,34 ;SELECT TRACK 34 CALL SEEK ;SEEK TO TRACK 34 JNC F14 ;OK, TURN MOTOR OFF F13: ; DSK_ERR: MOV SI,OFFSET F3 ;GET ADDR OF MSG MOV CX,F3L ;GET MSG BYTE COUNT CALL P_MSG ;GO PRINT ERROR MSG ; TURN DRIVE 0 MOTOR OFF F14: ; DR0_OFF: MOV AL,0CH ;TURN DRIVE 0 MOTOR OFF MOV DX,03F2H ; FDC CTL ADDRESS OUT DX,AL ; SETUP PRINTER AND RS232 BASE ADDRESSES IF DEVICE ATTACHED F15: ; JMP_BOOT: MOV BUFFER_HEAD,OFFSET KB_BUFFER ;SETUP KEYBOARD PARAMETERS MOV BUFFER_TAIL,OFFSET KB_BUFFER MOV BP,OFFSET F4 ; PRT_SRC_TBL MOV SI,0 F16: ; PRT_BASE: MOV DX,CS:[BP] ;GET PRINTER BASE ADDR MOV AL,0AAH ;WRITE DATA TO PORT A OUT DX,AL SUB AL,AL IN AL,DX ;READ PORT A CMP AL,0AAH ;DATA PATTERN SAME JNE F17 ;NO - CHECK NEXT PRT CD MOV PRINTER_BASE[SI],DX ;YES - STORE PRT BASE ADDR INC SI ;INCREMENT TO NEXT WORD INC SI F17: ; NO_STORE: INC BP ;POINT TO NEXT BASE ADDR INC BP CMP BP,OFFSET F4E ;ALL POSSIBLE ADDRS CHECKED? JNE F16 ;PRT_BASE MOV BX,0 ;POINTER TO RS232 TABLE MOV DX,3FAH ;CHECK IF RS232 CD 1 ATTCH? IN AL,DX ;READ INTR ID REG TEST AL,0F8H JNZ F18 MOV RS232_BASE[BX],3F8H ;SETUP RS232 CD #1 ADDR INC BX INC BX F18: MOV DX,2FAH ;CHECK IF RS232 CD 2 ATTCH IN AL,DX ;READ INTERRUPT ID REG TEST AL,0F8H JNZ F19 ;BASE_END MOV RS232_BASE[BX],2F8H ;SETUP RS232 CD #2 INC BX INC BX ;------ SET UP EQUIP FLAG TO INDICATE NUMBER OF PRINTERS AND RS232 CARDS F19: ; BASE_END: MOV AX,SI ; SI HAS 2* NUMBER OF RS232 MOV CL,3 ; SHIFT COUNT ROR AL,CL ; ROTATE RIGHT 3 POSITIONS OR AL,BL ; OR IN THE PRINTER COUNT MOV BYTE PTR EQUIP_FLAG+1,AL ; STORE AS SECOND BYTE MOV DX,201H IN AL,DX TEST AL,0FH JNZ F20 ; NO_GAME_CARD OR BYTE PTR EQUIP_FLAG+1,16 F20: ; NO_GAME_CARD: ; ENABLE NMI INTERRUPTS MOV AL,80H ;ENABLE NMI INTERRUPTS OUT 0A0H,AL CMP MFG_TST,1 ;MFG MODE? JE F21 ; LOAD_BOOT_STRAP MOV DX,1 ; CALL ERR_BEEP ;BEEP 1 SHORT TONE F21: ; LOAD_BOOT_STRAP: JMP BOOT_STRAP ;GO TO THE BOOT LOADER F22: ; LOOP_POD: CMP MFG_TST,1 ;MANUFACTURING TEST MODE? JNE F23 ;NO - GO TO BOOT LOADER JMP START ;YES - LOOP POWER-ON-DIAGS F23: ; GO_TO_BOOT: JMP F15 ; JMP_BOOT ;-------------------------------------------- ; INITIAL RELIABILITY TEST -- SUBROUTINES ;-------------------------------------------- ASSUME CS:CODE,DS:DATA ;-------------------------------------------- ; SUBROUTINES FOR POWER ON DIAGNOSTICS ;-------------------------------------------- ; THIS PROCEDURE WILL ISSUE ONE LONG TONE (3 SECS) AND ONE OR ; MORE SHORT TONES (1 SEC) TO INDICATE A FAILURE ON THE PLANAR ; BOARD, A BAD RAM MODULE, OR A PROBLEM WITH THE CRT. ;ENTRY PARAMETERS: ; DH = NUMBER OF LONG TONES TO BEEP ; DL = NUMBER OF SHORT TONES TO BEEP. ;-------------------------------------------- ERR_BEEP PROC NEAR PUSHF ;SAVE FLAGS CLI ;DISABLE SYSTEM INTERRUPTS PUSH DS ;SAVE DS REG CONTENTS MOV AX,DATA ;POINT DS TO DATA SEG MOV DS,AX OR DH,DH ; ANY LONG ONES TO BEEP JZ G3 ; NO, DO THE SHORT ONES G1: ; LONG_BEEP: MOV BL,6 ; COUNTER FOR BEEPS CALL BEEP ; DO THE BEEP G2: LOOP G2 ; DELAY BETWEEN BEEPS DEC DH ; ANY MORE TO DO JNZ G1 ; DO IT CMP MFG_TST,1 ; MFG TEST MODE? JNE G3 ; YES - CONTINUE BEEPING SPEAKER MOV AL,0CDH ; STOP BLINKING LED OUT PORT_B,AL JMP SHORT G1 G3: ; SHORT_BEEP: MOV BL,1 ; COUNTER FOR A SHORT BEEP CALL BEEP ; DO THE SOUND G4: LOOP G4 ; DELAY BETWEEN BEEPS DEC DL ; DONE WITH SHORTS JNZ G3 ; DO SOME MORE G5: LOOP G5 ; LONG DELAY BEFORE RETURN G6: LOOP G6 POP DS ;RESTORE ORIG CONTENTS OF DS POPF ;RESTORE FLAGS TO ORIG SETTINGS RET ; RETURN TO CALLER ERR_BEEP ENDP ; ROUTINE TO SOUND BEEPER BEEP PROC NEAR MOV AL,10110110B ;SEL TIM 2,LSB,MSB,BINARY OUT TIMER+3,AL ;WRITE THE TIMER MODE REG MOV AX,533H ;DIVISOR FOR 1000 HZ OUT TIMER+2,AL ;WRITE TIMER 2 CNT - LSB MOV AL,AH OUT TIMER+2,AL ;WRITE TIMER 2 CNT - MSB IN AL,PORT_B ;GET CURRENT SETTING OF PORT MOV AH,AL ; SAVE THAT SETTING OR AL,03 ;TURN SPEAKER ON OUT PORT_B,AL SUB CX,CX ;SET CNT TO WAIT 500 MS G7: LOOP G7 ;DELAY BEFORE TURNING OFF DEC BL ;DELAY CNT EXPIRED? JNZ G7 ;NO - CONTINUE BEEPING SPK MOV AL,AH ; RECOVER VALUE OF PORT OUT PORT_B,AL RET ;RETURN TO CALLER BEEP ENDP ;-------------------------------------------- ; THIS PROCEDURE WILL SEND A SOFTWARE RESET TO THE KEYBOARD. ; SCAN CODE 'AA' SHOULD BE RETURNED TO THE CPU. ;-------------------------------------------- KBD_RESET PROC NEAR MOV AL,0CH ;SET KBD CLK LINE LOW OUT PORT_B,AL ;WRITE 8255 PORT B MOV CX,10582 ;HOLD KBD CLK LOW FOR 20 MS G8: LOOP G8 ;LOOP FOR 20 MS MOV AL,0CCH ;SET CLK, ENABLE LINES HIGH OUT PORT_B,AL SP_TEST: ; ENTRY FOR MANUFACTURING TEST 2 MOV AL,4CH ;SET KBD CLK HIGH, ENABLE LOW OUT PORT_B,AL MOV AL,0FDH ;ENABLE KEYBOARD INTERRUPTS OUT INTA01,AL ;WRITE 8255 IMR STI ;ENABLE SYSTEM INTERRUPTS MOV AH,0 ;RESET INTERRUPT INDICATOR SUB CX,CX ;SETUP INTERRUPT TIMEOUT CNT G9: TEST AH,0FFH ;DID A KEYBOARD INTR OCCUR? JNZ G10 ;YES - READ SCAN CODE RETURNED LOOP G9 ;NO - LOOP TILL TIMEOUT G10: IN AL,PORT_A ;READ KEYBOARD SCAN CODE MOV BL,AL ;SAVE SCAN CODE JUST READ MOV AL,0CCH ;CLEAR KEYBOARD OUT PORT_B,AL RET ;RETURN TO CALLER KBD_RESET ENDP ;-------------------------------------------- ; BLINK LED PROCEDURE FOR MFG BURN-IN AND RUN-IN TESTS ; (LED WILL BLINK APPROXIMATELY .25 SECOND) ;-------------------------------------------- BLINK_INT PROC NEAR STI PUSH CX ;SAVE CX REG CONTENTS PUSH AX ;SAVE AX REG CONTENTS IN AL,PORT_B ;READ CURRENT VAL OF PORT B AND AL,0BFH OUT PORT_B,AL ;BLINK LED SUB CX,CX G11: LOOP G11 OR AL,40H ;STOP BLINKING LED OUT PORT_B,AL MOV AL,EOI OUT INTA00,AL POP AX ;RESTORE AX REG POP CX ;RESTORE CX REG IRET BLINK_INT ENDP ;-------------------------------------------- ; THIS SUBROUTINE WILL PRINT A MESSAGE ON THE DISPLAY ; ;ENTRY REQUIREMENTS: ; SI = OFFSET (ADDRESS) OF MESSAGE BUFFER ; CX = MESSAGE BYTE COUNT ; MAXIMUM MESSAGE LENGTH IS 36 CHARACTERS ;-------------------------------------------- P_MSG PROC NEAR MOV AX,DATA ;POINT DS TO DATA SEG MOV DS,AX CMP MFG_TST,1 ;MFG TEST MODE? JNE G12 ;NO - DISPLAY ERROR MSG MOV DH,1 ;YES - SETUP TO BEEP SPEAKER JMP ERR_BEEP ;YES - BEEP SPEAKER G12: ; WRITE_MSG: MOV AL,CS:[SI] ;PUT CHAR IN AL INC SI ; POINT TO NEXT CHAR MOV BH,0 ;SET PAGE # TO ZERO MOV AH,14 ;WRITE CHAR (TTY-INTERFACE) INT 10H ;CALL VIDEO_IO LOOP G12 ;CONTINUE TILL MSG WRITTEN MOV AX,0E0DH ;POSITION CURSOR TO NEXT LINE INT 10H ;SEND CARRIAGE RETURN AND MOV AX,0E0AH ;LINE FEED CHARS INT 10H RET P_MSG ENDP ;--- INT 19 ----------------------------- ;BOOT STRAP LOADER ; IF A 5 1/4" DISKETTE DRIVE IS AVAILABLE ; ON THE SYSTEM, TRACK 0, SECTOR 1 IS READ INTO THE ; BOOT LOCATION (SEGMENT 0, OFFSET 7C00) ; AND CONTROL IS TRANSFERRED THERE. ; ; IF THERE IS NO DISKETTE DRIVE, OR IF THERE IS ; IS A HARDWARE ERROR CONTROL IS TRANSFERRED ; TO THE CASSETTE BASIC ENTRY POINT. ; ; IPL ASSUMPTIONS ; 8255 PORT 60H BIT 0 ; = 1 IF IPL FROM DISKETTE ;----------------------------------------- ASSUME CS:CODE,DS:DATA BOOT_STRAP PROC NEAR STI ; ENABLE INTERRUPTS MOV AX,DATA ; ESTABLISH ADDRESSING MOV DS,AX MOV AX,EQUIP_FLAG ; GET THE EQUIPMENT SWITCHES TEST AL,1 ; ISOLATE IPL SENSE SWITCH JZ H3 ; GO TO CASSETTE BASIC ENTRY POINT ;------ MUST LOAD SYSTEM FROM DISKETTE -- CX HAS RETRY COUNT MOV CX,4 ; SET RETRY COUNT H1: ; IPL_SYSTEM PUSH CX ; SAVE RETRY COUNT MOV AH,0 ; RESET THE DISKETTE SYSTEM INT 13H ; DISKETTE_IO JC H2 ; IF ERROR, TRY AGAIN MOV AH,2 ; READ IN THE SINGLE SECTOR MOV BX,0 ; TO THE BOOT LOCATION MOV ES,BX MOV BX,OFFSET BOOT_LOCN MOV DX,0 ; DRIVE 0, HEAD 0 MOV CX,1 ; SECTOR 1, TRACK 0 MOV AL,1 ; READ ONE SECTOR INT 13H ; DISKETTE_IO H2: POP CX ; RECOVER RETRY COUNT JNC H4 ; CF SET BY UNSUCCESSFUL READ LOOP H1 ; DO IT FOR RETRY TIMES ;------ UNABLE TO IPL FROM THE DISKETTE H3: ; CASSETTE_JUMP: INT 18H ; USE INTERRUPT VECTOR TO GET TO BASIC ;------ IPL WAS SUCCESSFUL H4: JMP BOOT_LOCN BOOT_STRAP ENDP ;-----INT 14--------------------------------- ;RS232_IO ; THIS ROUTINE PROVIDES BYTE STREAM I/O TO THE COMMUNICATIONS ; PORT ACCORDING TO THE PARAMETERS: ; (AH)=0 INITIALIZE THE COMMUNICATIONS PORT ; (AL) HAS PARMS FOR INITIALIZATION ; ; 7 6 5 4 3 2 1 0 ; ----- BAUD RATE -- -PARITY-- STOPBIT --WORD LENGTH-- ; ; 000 - 110 X0 - NONE 0 - 1 10 - 7 BITS ; 001 - 150 01 - ODD 1 - 2 11 - 8 BITS ; 010 - 300 11 - EVEN ; 011 - 600 ; 100 - 1200 ; 101 - 2400 ; 110 - 4800 ; 111 - 9600 ; ON RETURN, CONDITIONS SET AS IN CALL TO COMMO STATUS (AH=3) ; (AH)=1 SEND THE CHARACTER IN (AL) OVER THE COMMO LINE ; (AL) REGISTER IS PRESERVED ; ON EXIT, BIT 7 OF AH IS SET IF THE ROUTINE WAS UNABLE TO ; TO TRANSMIT THE BYTE OF DATA OVER THE LINE. THE ; REMAINDER OF AH IS SET AS IN A STATUS REQUEST, ; REFELECTING THE CURRENT STATUS OF THE LINE. ; (AH)=2 RECEIVE A CHARACTER IN (AL) FROM COMMO LINE BEFORE ; RETURNING TO CALLER ; ON EXIT, AH HAS THE CURRENT LINE STATUS, AS SET BY THE ; THE STATUS ROUTINE, EXCEPT THAT THE ONLY BITS ; LEFT ON ARE THE ERROR BITS (7,4,3,2,1) ; IN THIS CASE, THE TIME OUT BIT INDICATES DATA SET ; READY WAS NOT RECEIVED. ; THUS, AH IS NON ZERO ONLY WHEN AN ERROR OCCURRED. ; (AH)=3 RETURN THE COMMO PORT STATUS IN (AX) ; AH CONTAINS THE LINE CONTROL STATUS ; BIT 7 = TIME OUT ; BIT 6 = TRANS SHIFT REGISTER EMPTY ; BIT 5 = TRAN HOLDING REGISTER EMPTY ; BIT 4 = BREAK DETECT ; BIT 3 = FRAMING ERROR ; BIT 2 = PARITY ERROR ; BIT 1 = OVERRUN ERROR ; BIT 0 = DATA READY ; AL CONTAINS THE MODEM STATUS ; BIT 7 = RECEVED LINE SIGNAL DETECT ; BIT 6 = RING INDICATOR ; BIT 5 = DATA SET READY ; BIT 4 = CLEAR TO SEND ; BIT 3 = DELTA RECEIVE LINE SIGNAL DETECT ; BIT 2 = TRAILING EDGE RING DETECTOR ; BIT 1 = DELTA DATA SET READY ; BIT 0 = DELTA CLEAR TO SEND ; ; (DX) = PARAMETER INDICATING WHICH RS232 CARD (0,1 ALLOWED) ; DATA AREA RS232_BASE CONTAINS THE BASE ADDRESS OF THE 8250 ON THE CARD ; LOCATION 400H CONTAINS UP TO 4 RS232 ADDRESSES POSSIBLE ;OUTPUT ; AX MODIFIED ACCORDING TO PARMS OF CALL ; ALL OTHERS UNCHANGED ;------------------------------------ ASSUME CS:CODE,DS:DATA A1 LABEL WORD DW 1047 ; 110 BAUD ; TABLE OF INIT VALUE DW 768 ; 150 DW 384 ; 300 DW 192 ; 600 DW 96 ; 1200 DW 48 ; 2400 DW 24 ; 4800 DW 12 ; 9600 RS232_IO PROC FAR ;------ VECTOR TO APPROPRIATE ROUTINE STI ; INTERRUPTS BACK ON PUSH DS ; SAVE SEGMENT PUSH DX PUSH SI PUSH DI PUSH CX MOV SI,DX ; RS232 VALUE TO SI SHL SI,1 ; WORD OFFSET MOV DX,DATA MOV DS,DX ; SET UP OUR SEGMENT MOV DX,RS232_BASE[SI] ; GET BASE ADDRESS OR DX,DX ; TEST FOR 0 BASE ADDRESS JZ A3 ; RETURN OR AH,AH ; TEST FOR (AH)=0 JZ A4 ; COMMUN INIT DEC AH ; TEST FOR (AH)=1 JZ A5 ; SEND AL DEC AH ; TEST FOR (AH)=2 JNZ A2 JMP A12 ; RECEIVE INTO AL A2: DEC AH ; TEST FOR (AH)=3 JNZ A3 JMP A18 ; COMMUNICATION STATUS A3: ; RETURN FROM RS232 POP CX POP DI POP SI POP DX POP DS IRET ; RETURN TO CALLER, NO ACTION ;------ INITIALIZE THE COMMUNICATIONS PORT A4: MOV AH,AL ; SAVE INIT PARMS IN AH ADD DX,3 ; POINT TO 8250 CONTROL REGISTER MOV AL,80H OUT DX,AL ; SET DLAB=1 ;------ DETERMINE BAUD RATE DIVISOR MOV DL,AH ; GET PARMS TO DL ROL DL,1 ROL DL,1 ; GET BAUD RATE TERM TO LOW BITS ROL DL,1 ROL DL,1 ; *2 FOR WORD TABLE ACCESS AND DX,0EH ; ISOLATE THEM MOV DI,OFFSET A1 ; BASE OF TABLE ADD DI,DX ; PUT INTO INDEX REGISTER MOV DX,RS232_BASE[SI] ; POINT TO HIGH ORDER OF DIVISOR INC DX MOV AL,CS:[DI]+1 ; GET HIGH ORDER OF DIVISOR OUT DX,AL ; SET MS OF DIV TO 0 DEC DX MOV AL,CS:[DI] ; GET LOW ORDER OF DIVISOR OUT DX,AL ; SET LOW OF DIVISOR ADD DX,3 MOV AL,AH ; GET PARMS BACK AND AL,01FH ; STRIP OFF THE BAUD BITS OUT DX,AL ; LINE CONTROL TO 8 BITS SUB DX,2 MOV AL,0 OUT DX,AL ; INTERRUPT ENABLES ALL OFF JMP SHORT A18 ; COM_STATUS ;------ SEND CHARACTER IN (AL) OVER COMMO LINE A5: PUSH AX ; SAVE CHAR TO SEND ADD DX,4 ; MODEM CONTROL REGISTER MOV AL,3 ; DTR AND RTS OUT DX,AL ; DATA TERMINAL READY, REQUEST TO SEND XOR CX,CX ; INITIALIZE TIME OUT COUNTER ADD DX,2 ; MODEM STATUS REGISTER A6: ; WAIT_DATA_SET_READY IN AL,DX ; GET MODEM STATUS TEST AL,20H ; DATA SET READY JNZ A7 ; TEST_CLEAR_TO_SEND LOOP A6 ; WAIT_DATA_SET_READY POP AX OR AH,80 ; INDICATE TIME OUT JMP A3 ; RETURN A7: ; TEST_CLEAR_TO_SEND SUB CX,CX A8: ; WAIT_CLEAR_TO_SEND IN AL,DX ; GET MODEM STATUS TEST AL,10H ; TEST CLEAR TO SEND JNZ A9 ; CLEAR_TO_SEND LOOP A8 ; WAIT_CLEAR_TO_SEND POP AX ; TIME OUT HAS OCCURRED OR AH,80H JMP A3 ; RETURN A9: ; CLEAR_TO_SEND DEC DX ; LINE STATUS REGISTER SUB CX,CX ; INITIALIZE WAIT COUNT A10: ; WAIT_SEND IN AL,DX ; GET STATUS TEST AL,20H ; IS TRANSMITTER READY JNZ A11 ; OUT_CHAR LOOP A10 ; GO BACK FOR MORE, AND TEST FOR TIME OUT POP AX ; RECOVER ORIGINAL INPUT OR AH,80H ; SET THE TIME OUT BIT JMP A3 ; RETURN A11: ; OUT_CHAR SUB DX,5 ; DATA PORT POP CX ; RECOVER IN CX TEMPORARILY MOV AL,CL ; GET OUT CHAR TO AL FOR OUT, STATUS IN AH OUT DX,AL ; OUTPUT CHARACTER JMP A3 ; RETURN ;------ RECEIVE CHARACTER FROM COMMO LINE A12: AND BIOS_BREAK,07FH ; TURN OFF BREAK BIT IN BYTE ADD DX,4 ; MODEM CONTROL REGISTER MOV AL,1 ; DATA TERMINAL READY OUT DX,AL ADD DX,2 ; MODEM STATUS REGISTER SUB CX,CX ; ESTABLISH TIME OUT COUNT A13: ; WAIT_DSR IN AL,DX ; MODEM STATUS TEST AL,20H ; DATA SET READY JNZ A15 ; IS IT READY YET LOOP A13 ; WAIT UNTIL IT IS A14: ; TIME_OUT_ERR MOV AH,80H ; SET TIME OUT ERROR JMP A3 ; RETURN WITH ERROR A15: ; WAIT_DSR_END DEC DX ; LINE STATUS REGISTER A16: ; WAIT_RECV IN AL,DX ; GET STATUS TEST AL,1 ; RECEIVE BUFFER FULL JNZ A17 ; GET CHAR TEST BIOS_BREAK,80H ; TEST FOR BREAK KEY JZ A16 ; LOOP IF NOT JMP A14 ; SET TIME OUT ERROR A17: ; GET_CHAR AND AL,00011110B ; TEST FOR ERROR CONDITIONS ON RECV CHAR MOV AH,AL ; SAVE THIS PART OF STATUS FOR LATER OPERATION MOV DX,RS232_BASE[SI] ; DATA PORT IN AL,DX ; GET CHARACTER FROM LINE JMP A3 ; RETURN ;------ COMMO PORT STATUS ROUTINE A18: MOV DX,RS232_BASE[SI] ADD DX,5 ; CONTROL PORT IN AL,DX ; GET LINE CONTROL STATUS MOV AH,AL ; PUT IN AH FOR RETURN INC DX ; POINT TO MODEM STATUS REGISTER IN AL,DX ; GET MODEM CONTROL STATUS JMP A3 ; RETURN RS232_IO ENDP ;---- INT 16 -------------------------------- ; KEYBOARD I/O ; THESE ROUTINES PROVIDE KEYBOARD SUPPORT ; INPUT ; (AH)=0 READ THE NEXT ASCII CHARACTER STRUCK FROM THE KEYBOARD ; RETURN THE RESULT IN (AL), SCAN CODE IN (AH) ; (AH)=1 SET THE Z FLAG TO INDICATE IF AN ASCII CHARACTER IS AVAILABLE ; TO BE READ. ; (ZF)=1 -- NO CODE AVAILABLE ; (ZF)=0 -- CODE IS AVAILABLE ; IF ZF = 0, THE NEXT CHARACTER IN THE BUFFER TO BE READ IS ; IN AX, AND THE ENTRY REMAINS IN THE BUFFER ; (AH)=2 RETURN THE CURRENT SHIFT STATUS IN AL REGISTER ; THE BIT SETTINGS FOR THIS CODE ARE INDICATED IN THE ; THE EQUATES FOR KB_FLAG ; OUTPUT ; AS NOTED ABOVE, ONLY AX AND FLAGS CHANGED ; ALL REGISTERS RETAINED ;---------------------------------------- ASSUME CS:CODE,DS:DATA KEYBOARD_IO PROC FAR STI ; INTERRUPTS BACK ON PUSH DS ; SAVE CURRENT DS PUSH BX ; SAVE BX TEMPORARILY MOV BX,DATA ; MOV DS,BX ; ESTABLISH POINTER TO DATA REGION OR AH,AH ; AH=0 JZ K1 ; ASCII_READ DEC AH ; AH=1 JZ K2 ; ASCII_STATUS DEC AH ; AH=2 JZ K3 ; SHIFT_STATUS POP BX ; RECOVER REGISTER POP DS IRET ; INVALID COMMAND ;------ READ THE KEY TO FIGURE OUT WHAT TO DO K1: ; ASCII READ STI ; INTERRUPTS BACK ON DURING LOOP NOP ; ALLOW AN INTERRUPT TO OCCUR CLI ; INTERRUPTS BACK OFF MOV BX,BUFFER_HEAD ; GET POINTER TO HEAD OF BUFFER CMP BX,BUFFER_TAIL ; TEST END OF BUFFER JZ K1 ; LOOP UNTIL SOMETHING IN BUFFER MOV AX,[BX] ; GET SCAN CODE AND ASCII CODE CALL K4 ; MOVE POINTER TO NEXT POSITION MOV BUFFER_HEAD,BX ; STORE VALUE IN VARIABLE POP BX ; RECOVER REGISTER POP DS ; RECOVER SEGMENT IRET ; RETURN TO CALLER ;------ ASCII STATUS K2: CLI ; INTERRUPTS OFF MOV BX,BUFFER_HEAD ; GET HEAD POINTER CMP BX,BUFFER_TAIL ; IF EQUAL (Z=1) THEN NOTHING HERE MOV AX,[BX] STI ; INTERRUPTS BACK ON POP BX ; RECOVER REGISTER POP DS ; RECOVER SEGMENT RET 2 ; THROW AWAY FLAGS ;------ SHIFT STATUS K3: MOV AL,KB_FLAG ; GET THE SHIFT STATUS FLAGS POP BX ; RECOVER REGISTER POP DS ; RECOVER REGISTERS IRET ; RETURN TO CALLER KEYBOARD_IO ENDP ;------ INCREMENT A BUFFER POINTER K4 PROC NEAR ADD BX,2 ; MOVE TO NEXT WORD IN LIST CMP BX,OFFSET KB_BUFFER_END ; AT END OF BUFFER? JNE K5 ; NO, CONTINUE MOV BX,OFFSET KB_BUFFER ; YES, RESET TO BUFFER BEGINNING K5: RET K4 ENDP ;------ TABLE OF SHIFT KEYS AND MASK VALUES K6 LABEL BYTE DB INS_KEY ; INSERT KEY DB CAPS_KEY,NUM_KEY,SCROLL_KEY,ALT_KEY,CTL_KEY DB LEFT_KEY,RIGHT_KEY K6L EQU $-K6 ;------ SHIFT_MASK_TABLE K7 LABEL BYTE DB INS_SHIFT ; INSERT MODE SHIFT DB CAPS_SHIFT,NUM_SHIFT,SCROLL_SHIFT,ALT_SHIFT,CTL_SHIFT DB LEFT_SHIFT,RIGHT_SHIFT ;------ SCAN CODE TABLES K8 DB 27,-1,0,-1,-1,-1,30,-1 DB -1,-1,-1,31,-1,127,-1,17 DB 23,5,18,20,25,21,9,15 DB 16,27,29,10,-1,1,19 DB 4,6,7,8,10,11,12,-1,-1 DB -1,-1,28,26,24,3,22,2 DB 14,13,-1,-1,-1,-1,-1,-1 DB ' ',-1 ;-------- CTL TABLE SCAN K9 LABEL BYTE DB 94,95,96,97,98,99,100,101 DB 102,103,-1,-1,119,-1,132,-1 DB 115,-1,116,-1,117,-1,118,-1 DB -1 ;------- LC TABLE K10 LABEL BYTE DB 01BH,'1234567890-=',08H,09H DB 'qwertyuiop[]',0DH,-1,'asdfghjkl;',027H DB 60H,-1,5CH,'zxcvbnm,./',-1,'*',-1,' ' DB -1 ;------ UC TABLE K11 LABEL BYTE DB 27,'!@#$',37,05EH,'&*()_+',08H,0 DB 'QWERTYUIOP{}',0DH,-1,'ASDFGHJKL:"' DB 07EH,-1,'|ZXCVBNM<>?',-1,0,-1,' ',-1 ;------ UC TABLE SCAN K12 LABEL BYTE DB 84,85,86,87,88,89,90 DB 91,92,93 ;------ ALT TABLE SCAN K13 LABEL BYTE DB 104,105,106,107,108 DB 109,110,111,112,113 ;------ NUM STATE TABLE K14 LABEL BYTE DB '789-456+1230.' ;------ BASE CASE TABLE K15 LABEL BYTE DB 71,72,73,-1,75,-1,77 DB -1,79,80,81,82,83 ;------ KEYBOARD INTERRUPT ROUTINE KB_INT PROC FAR STI ; ALLOW FURTHER INTERRUPTS PUSH AX PUSH BX PUSH CX PUSH DX PUSH SI PUSH DI PUSH DS PUSH ES CLD ; FORWARD DIRECTION MOV AX,DATA MOV DS,AX ; SET UP ADDRESSING IN AL,KB_DATA ; READ IN THE CHARACTER PUSH AX ; SAVE IT IN AL,KB_CTL ; GET THE CONTROL PORT MOV AH,AL ; SAVE VALUE OR AL,80H ; RESET BIT FOR KEYBOARD OUT KB_CTL,AL XCHG AH,AL ; GET BACK ORIGINAL CONTROL OUT KB_CTL,AL ; KB HAS BEEN RESET POP AX ; RECOVER SCAN CODE MOV AH,AL ; SAVE SCAN CODE IN AH ALSO ;------ TEST FOR OVERRUN SCAN CODE FROM KEYBOARD CMP AL,0FFH ; IS THIS AN OVERRUN CHAR JNZ K16 ; NO, TEST FOR SHIFT KEY JMP K62 ; BUFFER_FULL_BEEP ;------ TEST FOR SHIFT KEYS K16: ; TEST_SHIFT AND AL,07FH ; TURN OFF THE BREAK BIT PUSH CS POP ES ; ESTABLISH ADDRESS OF SHIFT TABLE MOV DI,OFFSET K6 ; SHIFT KEY TABLE MOV CX,K6L ; LENGTH REPNE SCASB ; LOOK THROUGH THE TABLE FOR A MATCH MOV AL,AH ; RECOVER SCAN CODE JE K17 ; JUMP IF MATCH FOUND JMP K25 ; IF NO MATCH, THEN SHIFT NOT FOUND ;------ SHIFT KEY FOUND K17: SUB DI,OFFSET K6+1 ; ADJUST PTR TO SCAN CODE MTCH MOV AH,CS:K7[DI] ; GET MASK INTO AH TEST AL,80H ; TEST FOR BREAK KEY JNZ K23 ; BREAK_SHIFT_FOUND ;------ SHIFT MAKE FOUND, DETERMINE SET OR TOGGLE CMP AH,SCROLL_SHIFT JAE K18 ; IF SCROLL SHIFT OR ABOVE, TOGGLE KEY ;------ PLAIN SHIFT KEY, SET SHIFT ON OR KB_FLAG,AH ; TURN ON SHIFT BIT JMP K26 ; INTERRUPT_RETURN ;------ TOGGLED SHIFT KEY, TEST FOR 1ST MAKE OR NOT K18: ; SHIFT-TOGGLE TEST KB_FLAG, CTL_SHIFT ; CHECK CTL SHIFT STATE JNZ K25 ; JUMP IF CTL STATE CMP AL, INS_KEY ; CHECK FOR INSERT KEY JNZ K22 ; JUMP IF NOT INSERT KEY TEST KB_FLAG, ALT_SHIFT ; CHECK FOR ALTERNATE SHIFT JZ K19 ; JUMP IF NOT ALTERNATE SHIFT JMP K25 ; JUMP IF ALTERNATE SHIFT K19: TEST KB_FLAG, NUM_STATE ; CHECK FOR BASE STATE JNZ K21 ; JUMP IF NUM LOCK IS ON TEST KB_FLAG, LEFT_SHIFT+RIGHT_SHIFT JZ K22 ; JUMP IF BASE STATE K20: ; NUMERIC ZERO, NOT INSERT KEY MOV AX, 5230H ; PUT OUT AN ASCII ZERO JMP K57 ; BUFFER_FILL K21: ; MIGHT BE NUMERIC TEST KB_FLAG, LEFT_SHIFT+RIGHT_SHIFT JZ K20 ; JUMP NUMERIC, NOT INSERT K22: ; SHIFT TOGGLE KEY HIT; PROCESS IT TEST AH,KB_FLAG_1 ; IS KEY ALREADY DEPRESSED JNZ K26 ; JUMP IF KEY ALREADY DEPRESSED OR KB_FLAG_1,AH ; INDICATE THAT THE KEY IS DEPRESSED XOR KB_FLAG,AH ; TOGGLE THE SHIFT STATE CMP AL,INS_KEY ; TEST FOR 1ST MAKE OF INSERT KEY JNE K26 ; JUMP IF NOT INSERT KEY MOV AX,INS_KEY*256 ; SET SCAN CODE INTO AH, 0 INTO AL JMP K57 ; PUT INTO OUTPUT BUFFER ;------ BREAK SHIFT FOUND K23: ; BREAK-SHIFT-FOUND CMP AH,SCROLL_SHIFT ; IS THIS A TOGGLE KEY JAE K24 ; YES, HANDLE BREAK TOGGLE NOT AH ; INVERT MASK AND KB_FLAG,AH ; TURN OFF SHIFT BIT CMP AL,ALT_KEY+80H ; IS THIS ALTERNATE SHIFT RELEASE JNE K26 ; INTERRUPT_RETURN ;------ ALTERNATE SHIFT KEY RELEASED, GET THE VALUE INTO BUFFER MOV AL,ALT_INPUT MOV AH,0 ; SCAN CODE OF 0 MOV ALT_INPUT,AH ; ZERO OUT THE FIELD CMP AL,0 ; WAS THE INPUT=0 JE K26 ; INTERRUPT_RETURN JMP K58 ; IT WASN'T, SO PUT IN BUFFER K24: ; BREAK-TOGGLE NOT AH ; INVERT MASK AND KB_FLAG_1,AH ; INDICATE NO LONGER DEPRESSED JMP SHORT K26 ; INTERRUPT_RETURN ;------ TEST FOR HOLD STATE K25: ; NO-SHIFT-FOUND CMP AL,80H ; TEST FOR BREAK KEY JAE K26 ; NOTHING FOR BREAK CHARS FROM HERE ON TEST KB_FLAG_1,HOLD_STATE ; ARE WE IN HOLD STATE JZ K28 ; BRANCH AROUND TEST IF NOT CMP AL,NUM_KEY JE K26 ; CAN'T END HOLD ON NUM_LOCK AND KB_FLAG_1,NOT HOLD_STATE ; TURN OFF THE HOLD STATE BIT K26: ; INTERRUPT-RETURN CLI ; TURN OFF INTERRUPTS MOV AL,EOI ; END OF INTERRUPT COMMAND OUT 020H,AL ; SEND COMMAND TO INTERRUPT CONTROL PORT K27: ; INTERRUPT-RETURN-NO-EOI POP ES POP DS POP DI POP SI POP DX POP CX POP BX POP AX ; RESTORE STATE IRET ; RETURN, INTERRUPTS BACK ON WITH FLAG CHANGE ;------ NOT IN HOLD STATE, TEST FOR SPECIAL CHARS K28: ; NO-HOLD-STATE TEST KB_FLAG,ALT_SHIFT ; ARE WE IN ALTERNATE SHIFT JNZ K29 ; JUMP IF ALTERNATE SHIFT JMP K38 ; JUMP IF NOT ALTERNATE ;------ TEST FOR RESET KEY SENTENCE (CTL ALT DEL) K29: ; TEST-RESET TEST KB_FLAG,CTL_SHIFT ; ARE WE IN CONTROL SHIFT ALSO JZ K31 ; NO_RESET CMP AL,DEL_KEY ; SHIFT STATE IS THERE, TEST KEY JNE K31 ; NO_RESET ;------ CTL-ALT-DEL HAS BEEN FOUND, DO I/O CLEANUP MOV RESET_FLAG, 1234H ; SET FLAG FOR RESET FACTION JMP RESET ; JUMP TO POWER ON DIAGNOSTICS ;------ ALT-INPUT-TABLE K30 LABEL BYTE DB 82,79,80,81,75,76,77 DB 71,72,73 ; 10 NUMBERS ON KEYPAD ;------ SUPER-SHIFT-TABLE DB 16,17,18,19,20,21,22,23 ; A-Z TYPEWRITER CHARS DB 24,25,30,31,32,33,34,35 DB 36,37,38,44,45,46,47,48 DB 49,50 ;------ IN ALTERNATE SHIFT, RESET NOT FOUND K31: ; NO-RESET CMP AL,57 ; TEST FOR SPACE KEY JNE K32 ; NOT THERE MOV AL,' ' ; SET SPACE CHAR JMP K57 ; BUFFER_FILL ;------ LOOK FOR KEY PAD ENTRY K32: ; ALT-KEY-PAD MOV DI,OFFSET K30 ; ALT-INPUT-TABLE MOV CX,10 ; LOOK FOR ENTRY USING KEYPAD REPNE SCASB ; LOOK FOR MATCH JNE K33 ; NO_ALT_KEYPAD SUB DI,OFFSET K30+1 ; DI NOW HAS ENTRY VALUE MOV AL,ALT_INPUT ; GET THE CURRENT BYTE MOV AH,10 ; MULTIPLY BY 10 MUL AH ADD AX,DI ; ADD IN THE LATEST ENTRY MOV ALT_INPUT,AL ; STORE IT AWAY JMP K26 ; THROW AWAY THAT KEYSTROKE ;------ LOOK FOR SUPERSHIFT ENTRY K33: ; NO-ALT-KEYPAD MOV ALT_INPUT,0 ; ZERO ANY PREVIOUS ENTRY INTO INPUT MOV CX,26 ; DI, ES ALREADY POINTING REPNE SCASB ; LOOK FOR MATCH IN ALPHABET JNE K34 ; NOT FOUND, FUNCTION KEY OR OTHER MOV AL,0 ; ASCII CODE OF ZERO JMP K57 ; PUT IT IN THE BUFFER ;------ LOOK FOR TOP ROW OF ALTERNATE SHIFT K34: ; ALT-TOP-ROW CMP AL,2 ; KEY WITH '1' ON IT JB K35 ; NOT ONE OF INTERESTING KEYS CMP AL,14 ; IS IT IN THE REGION JAE K35 ; ALT-FUNCTION ADD AH,118 ; CONVERT PSUEDO SCAN CODE TO RANGE MOV AL,0 ; INDICATE AS SUCH JMP K57 ; BUFFER_FILL ;------ TRANSLATE ALTERNATE SHIFT PSEUDO SCAN CODES K35: ; ALT-FUNCTION CMP AL,59 ; TEST FOR IN TABLE JAE K37 ; ALT-CONTINUE K36: ; CLOSE-RETURN JMP K26 ; IGNORE THE KEY K37: ; ALT-CONTINUE CMP AL,71 ; IN KEYPAD REGION JAE K36 ; IF SO, IGNORE MOV BX,OFFSET K13 ; ALT SHIFT PSEUDO SCAN TABLE JMP K63 ; TRANSLATE THAT ;------ NOT IN ALTERNATE SHIFT K38: ; NOT-ALT-SHIFT TEST KB_FLAG,CTL_SHIFT ; ARE WE IN CONTROL SHIFT JZ K44 ; NOT-CTL-SHIFT ;------ CONTROL SHIFT, TEST SPECIAL CHARACTERS ;------ TEST FOR BREAK AND PAUSE KEYS CMP AL,SCROLL_KEY ; TEST FOR BREAK JNE K39 ; NO-BREAK MOV BX,OFFSET KB_BUFFER ; RESET BUFFER TO EMPTY MOV BUFFER_HEAD,BX ; MOV BUFFER_TAIL,BX ; MOV BIOS_BREAK,80H ; TURN ON BIOS_BREAK BIT INT 1BH ; BREAK INTERRUPT VECTOR MOV AX,0 ; PUT OUT DUMMY CHARACTER JMP K57 ; BUFFER_FILL K39: ; NO-BREAK CMP AL,NUM_KEY ; LOOK FOR PAUSE KEY JNE K41 ; NO-PAUSE OR KB_FLAG_1,HOLD_STATE ; TURN ON THE HOLD FLAG MOV AL,EOI ; END OF INTERRUPT TO CONTROL PORT OUT 020H,AL ; ALLOW FURTHER KEYSTROKE INTS ;------ DURING PAUSE INTERVAL, TURN CRT BACK ON CMP CRT_MODE,7 ; IS THIS BLACK AND WHITE CARD JE K40 ; YES, NOTHING TO DO MOV DX,03D8H ; PORT FOR COLOR CARD MOV AL,CRT_MODE_SET ; GET THE VALUE OF THE CURRENT MODE OUT DX,AL ; SET THE CRT MODE, SO THAT CRT IS ON K40: ; PAUSE-LOOP TEST KB_FLAG_1,HOLD_STATE JNZ K40 ; LOOP UNTIL FLAG TURNED OFF JMP K27 ; INTERRUPT_RETURN_NO_EOI K41: ; NO-PAUSE ;------ TEST SPECIAL CASE KEY 55 CMP AL,55 JNE K42 ; NOT-KEY-55 MOV AX,114*256 ; START/STOP PRINTING SWITCH JMP K57 ; BUFFER_FILL ;------ SET UP TO TRANSLATE CONTROL SHIFT K42: ; NOT-KEY-55 MOV BX,OFFSET K8 ; SET UP TO TRANSLATE CTL CMP AL,59 ; IS IT IN TABLE JAE K43 ; CTL-TABLE-TRANSLATE JMP K56 ; YES, GO TRANSLATE CHAR K43: ; CTL-TABLE-TRANSLATE MOV BX,OFFSET K9 ; CTL TABLE SCAN JMP K63 ; TRANSLATE_SCAN ;------ NOT IN CONTROL SHIFT K44: ; NOT-CTL-SHIFT CMP AL,71 ; TEST FOR KEYPAD REGION JAE K48 ; HANDLE KEYPAD REGION TEST KB_FLAG,LEFT_SHIFT+RIGHT_SHIFT JZ K54 ; TEST FOR SHIFT STATE ;------ UPPER CASE, HANDLE SPECIAL CASES CMP AL,15 ; BACK TAB KEY JNE K45 ; NOT-BACK-TAB MOV AX,15*256 ; SET PSEUDO SCAN CODE JMP K57 ; BUFFER_FILL K45: ; NOT-BACK-TAB CMP AL,55 ; PRINT SCREEN KEY JNE K46 ; NOT-PRINT-SCREEN ;------ ISSUE INTERRUPT TO INDICATE PRINT SCREEN FUNCTION MOV AL,EOI ; END OF CURRENT INTERRUPT OUT 020H,AL ; SO FURTHER THINGS CAN HAPPEN INT 5H ; ISSUE PRINT SCREEN INTERRUPT JMP K27 ; GO BACK WITHOUT EOI OCCURRING K46: ; NOT-PRINT-SCREEN CMP AL,59 ; FUNCTION KEYS JB K47 ; NOT-UPPER-FUNCTION MOV BX,OFFSET K12 ; UPPER CASE PSEUDO SCAN CODES JMP K63 ; TRANSLATE_SCAN K47: ; NOT-UPPER-FUNCTION MOV BX,OFFSET K11 ; POINT TO UPPER CASE TABLE JMP SHORT K56 ; OK, TRANSLATE THE CHAR ;------ KEYPAD KEYS, MUST TEST NUM LOCK FOR DETERMINATION K48: ; KEYPAD-REGION TEST KB_FLAG,NUM_STATE ; ARE WE IN NUM_LOCK JNZ K52 ; TEST FOR SURE TEST KB_FLAG,LEFT_SHIFT+RIGHT_SHIFT ; ARE WE IN SHIFT STATE JNZ K53 ; IF SHIFTED, REALLY NUM STATE ;------ BASE CASE FOR KEYPAD K49: ; BASE-CASE CMP AL,74 ; SPECIAL CASE FOR A COUPLE OF KEYS JE K50 ; MINUS CMP AL,78 JE K51 SUB AL,71 ; CONVERT ORIGIN MOV BX,OFFSET K15 ; BASE CASE TABLE JMP SHORT K64 ; CONVERT TO PSEUDO SCAN K50: MOV AX,74*256+'-' ; MINUS JMP SHORT K57 ; BUFFER_FILL K51: MOV AX,78*256+'+' ; PLUS JMP SHORT K57 ; BUFFER_FILL ;------ MIGHT BE NUM LOCK, TEST SHIFT STATUS K52: ; ALMOST-NUM-STATE TEST KB_FLAG,LEFT_SHIFT+RIGHT_SHIFT JNZ K49 ; SHIFTED TEMP OUT OF NUM STATE K53: ; REALLY_NUM_STATE SUB AL,70 ; CONVERT ORIGIN MOV BX,OFFSET K14 ; NUM STATE TABLE JMP SHORT K56 ; TRANSLATE_CHAR ;------ PLAIN OLD LOWER CASE K54: ; NOT-SHIFT CMP AL,59 ; TEST FOR FUNCTION KEYS JB K55 ; NOT-LOWER-FUNCTION MOV AL,0 ; SCAN CODE IN AH ALREADY JMP SHORT K57 ; BUFFER_FILL K55: ; NOT-LOWER-FUNCTION MOV BX,OFFSET K10 ; LC TABLE ;------TRANSLATE THE CHARACTER K56: ; TRANSLATE-CHAR DEC AL ; CONVERT ORIGIN XLAT CS:K11 ; CONVERT THE SCAN CODE TO ASCII ;------ PUT CHARACTER INTO BUFFER K57: ; BUFFER-FILL CMP AL,-1 ; IS THIS AN IGNORE CHAR JE K59 ; YES, DO NOTHING WITH IT CMP AH,-1 ; LOOK FOR -1 PSEUDO SCAN JE K59 ; NEAR_INTERRUPT_RETURN ;------ HANDLE THE CAPS LOCK PROBLEM K58: ; BUFFER-FILL-NOTEST TEST KB_FLAG,CAPS_STATE ; ARE WE IN CAPS LOCK STATE JZ K61 ; SKIP IF NOT ;------ IN CAPS LOCK STATE TEST KB_FLAG,LEFT_SHIFT+RIGHT_SHIFT ; TEST FOR SHIFT STATE JZ K60 ; IF NOT SHIFT, CONVERT LOWER TO UPPER ;------ CONVERT ANY UPPER CASE TO LOWER CASE CMP AL,'A' ; FIND OUT IF ALPHABETIC JB K61 ; NOT_CAPS_STATE CMP AL,'Z' JA K61 ; NOT_CAPS_STATE ADD AL,'a'-'A' ; CONVERT TO LOWER CASE JMP SHORT K61 ; NOT_CAPS_STATE K59: ; NEAR-INTERRUPT-RETURN JMP K26 ; INTERRUPT_RETURN ;------ CONVERT ANY LOWER CASE TO UPPER CASE K60: ; LOWER-TO-UPPER CMP AL,'a' ; FIND OUT IF ALPHABETIC JB K61 ; NOT_CAPS_STATE CMP AL,'z' JA K61 ; NOT_CAPS_STATE SUB AL,'a'-'A' ; CONVERT TO UPPER CASE K61: ; NOT-CAPS-STATE MOV BX,BUFFER_TAIL ; GET THE END POINTER TO THE BUFFER MOV SI,BX ; SAVE THE VALUE CALL K4 ; ADVANCE THE TAIL CMP BX,BUFFER_HEAD ; HAS THE BUFFER WRAPPED AROUND JE K62 ; BUFFER_FULL_BEEP MOV [SI],AX ; STORE THE VALUE MOV BUFFER_TAIL,BX ; MOVE THE POINTER UP JMP K26 ; INTERRUPT_RETURN ;------ BUFFER IS FULL, SOUND THE BEEPER K62: ; BUFFER-FULL-BEEP CALL ERROR_BEEP JMP K26 ; INTERRUPT_RETURN ;------ TRANSLATE SCAN FOR PSEUDO SCAN CODES K63: ; TRANSLATE-SCAN SUB AL,59 ; CONVERT ORIGIN TO FUNCTION KEYS K64: ; TRANSLATE-SCAN-ORGD XLAT CS:K9 ; CTL TABLE SCAN MOV AH,AL ; PUT VALUE INTO AH MOV AL,0 ; ZERO ASCII CODE JMP K57 ; PUT IT INTO THE BUFFER KB_INT ENDP ERROR_BEEP PROC NEAR PUSH AX ; SAVE REGISTERS PUSH BX PUSH CX MOV BX,0C0H ; NUMBER OF CYCLES FOR 1/8 SECOND TONE IN AL,KB_CTL ; GET CONTROL INFORMATION PUSH AX ; SAVE K65: ; BEEP-CYCLE AND AL,0FCH ; TURN OFF TIMER GATE AND SPEAKER DATA OUT KB_CTL,AL ; OUTPUT TO CONTROL MOV CX,48H ; HALF CYCLE TIME FOR TONE K66: LOOP K66 ; SPEAKER OFF OR AL,2 ; TURN ON SPEAKER BIT OUT KB_CTL,AL ; OUTPUT TO CONTROL MOV CX,48H ; SET UP COUNT K67: LOOP K67 ; ANOTHER HALF CYCLE DEC BX ; TOTAL TIME COUNT JNZ K65 ; DO ANOTHER CYCLE POP AX ; RECOVER CONTROL OUT KB_CTL,AL ; OUTPUT THE CONTROL POP CX ; RECOVER REGISTERS POP BX POP AX RET ERROR_BEEP ENDP ;-- INT 13 ---------------------------------- ;DISKETTE I/O ; THIS INTERFACE PROVIDES ACCESS TO THE 5 1/4" DISKETTE DRIVES ;INPUT ; (AH)=0 RESET DISKETTE SYSTEM ; HARD RESET TO NEC, PREPARE COMMAND, RECAL REQD ON ALL DRIVES ; (AH)=1 READ THE STATUS OF THE SYSTEM INTO (AL) ; DISKETTE_STATUS FROM LAST OP'N IS USED ; REGISTERS FOR READ/WRITE/VERIFY/FORMAT ; (DL) - DRIVE NUMBER (0-3 ALLOWED, VALUE CHECKED) ; (DH) - HEAD NUMBER (0-1 ALLOWED, NOT VALUE CHECKED) ; (CH) - TRACK NUMBER (0-39, NOT VALUE CHECKED) ; (CL) - SECTOR NUMBER (1-8, NOT VALUE CHECKED) ; (AL) - NUMBER OF SECTORS ( MAX = 8, NOT VALUE CHECKED) ; ; (ES:BX) - ADDRESS OF BUFFER ( NOT REQUIRED FOR VERIFY) ; ; (AH)=2 READ THE DESIRED SECTORS INTO MEMORY ; (AH)=3 WRITE THE DESIRED SECTORS FROM MEMORY ; (AH)=4 VERIFY THE DESIRED SECTORS ; (AH)=5 FORMAT THE DESIRED TRACKS ; FOR THE FORMAT OPERATION, THE BUFFER POINTER (ES,BX) MUST ; POINT TO THE COLLECTION OF DESIRED ADDRESS FIELDS FOR THE ; TRACK. EACH FIELD IS COMPOSED OF 4 BYTES, (C,H,R,N), WHERE ; C = TRACK NUMBER, H=HEAD NUMBER, R = SECTOR NUMBER, N= NUMBER ; OF BYTES PER SECTOR (00=128, 01=256, 02=512, 03=1024,) ; THERE MUST BE ONE ENTRY FOR EVERY SECTOR ON THE TRACK. ; THIS INFORMATION IS USED TO FIND THE REQUESTED SECTOR DURING ; READ/WRITE ACCESS. ; DATA VARIABLE -- DISK_POINTER ; DOUBLE WORD POINTER TO THE CURRENT SET OF DISKETTE PARAMETERS ; OUTPUT ; AH = STATUS OF OPERATION ; STATUS BITS ARE DEFINED IN THE EQUATES FOR DISKETTE_STATUS ; VARIABLE IN THE DATA SEGMENT OF THIS MODULE ; CY = 0 SUCCESSFUL OPERATION (AH=0 ON RETURN) ; CY = 1 FAILED OPERATION (AH HAS ERROR REASON) ; FOR READ/WRITE/VERIFY ; DS,BX,DX,CH,CL PRESERVED ; AL = NUMBER OF SECTORS ACTUALLY READ ; ***** AL MAY NOT BE CORRECT IF TIME OUT ERROR OCCURS ; NOTE: IF AN ERROR IS REPORTED BY THE DISKETTE CODE, THE APPROPRIATE ; ACTION IS TO RESET THE DISKETTE, THEN RETRY THE OPERATION. ; ON READ ACCESSES, NO MOTOR START DELAY IS TAKEN, SO THAT ; THREE RETRIES ARE REQUIRED ON READS TO ENSURE THAT THE ; PROBLEM IS NOT DUE TO MOTOR START-UP. ;-------------------------------------------- ASSUME CS:CODE,DS:DATA,ES:DATA DISKETTE_IO PROC FAR STI ; INTERRUPTS BACK ON PUSH BX ; SAVE ADDRESS PUSH CX PUSH DS ; SAVE SEGMENT REGISTER VALUE PUSH SI ; SAVE ALL REGISTERS DURING OPERATION PUSH DI PUSH BP PUSH DX MOV BP,SP ; SET UP POINTER TO HEAD PARM MOV SI,DATA MOV DS,SI ; SET DATA REGION CALL J1 ; CALL THE REST TO ENSURE DS RESTORED MOV BX,4 ; GET THE MOTOR WAIT PARAMETER CALL GET_PARM MOV MOTOR_COUNT,AH ; SET THE TIMER COST FOR THE MOTOR MOV AH,DISKETTE_STATUS ; GET STATUS OF OPERATION CMP AH,1 ; SET THE CARRY FLAG TO INDICATE CMC ; SUCCESS OR FAILURE POP DX ; RESTORE ALL REGISTERS POP BP POP DI POP SI POP DS POP CX POP BX ; RECOVER ADDRESS RET 2 ; THROW AWAY SAVED FLAGS DISKETTE_IO ENDP J1 PROC NEAR MOV DH,AL ; SAVE # SECTORS IN DH AND MOTOR_STATUS,07FH ; INDICATE A READ OPERATION OR AH,AH ; AH=0 JZ DISK_RESET DEC AH ; AH=1 JZ DISK_STATUS MOV DISKETTE_STATUS,0 ; RESET THE STATUS INDICATOR CMP DL,4 ; TEST FOR DRIVE IN 0-3 RANGE JAE J3 ; ERROR IF ABOVE DEC AH ; AH=2 JZ DISK_READ DEC AH ; AH=3 JNZ J2 ; TEST_DISK_VERF JMP DISK_WRITE J2: ; TEST_DISK_VERF DEC AH ; AH=4 JZ DISK_VERF DEC AH ; AH=5 JZ DISK_FORMAT J3: ; BAD_COMMAND MOV DISKETTE_STATUS,BAD_CMD ; ERROR CODE, NO SECTORS TRANSFERRED RET ; UNDEFINED OPERATION J1 ENDP ;------ RESET THE DISKETTE SYSTEM DISK_RESET PROC NEAR MOV DX,03F2H ; ADAPTER CONTROL PORT CLI ; NO INTERRUPTS MOV AL,MOTOR_STATUS ; WHICH MOTOR IS ON MOV CL,4 ; SHIFT COUNT SAL AL,CL ; MOVE MOTOR VALUE TO HIGH NYBBLE TEST AL, 20H ; SELECT CORRESPONDING DRIVE JNZ J5 ; JUMP IF MOTOR ONE IS ON TEST AL, 40H JNZ J4 ; JUMP IF MOTOR TWO IS ON TEST AL, 80H JZ J6 ; JUMP IF MOTOR ZERO IS ON INC AL J4: INC AL J5: INC AL J6: OR AL,8 ; TURN ON INTERRUPT ENABLE OUT DX,AL ; RESET THE ADAPTER MOV SEEK_STATUS,0 ; SET RECAL REQUIRED ON ALL DRIVES MOV DISKETTE_STATUS,0 ; SET OK STATUS FOR DISKETTE OR AL,4 ; TURN OFF RESET OUT DX,AL ; TURN OFF THE RESET STI ; REENABLE THE INTERRUPTS CALL CHK_STAT_2 ; DO SENSE INTERRUPT STATUS FOLLOWING RESET MOV AL,NEC_STATUS ; IGNORE ERROR RETURN AND DO OWN RESET CMP AL,0C0H ; TEST FOR DRIVE READY TRANSITION JZ J7 ; EVERYTHING OK OR DISKETTE_STATUS,BAD_NEC ; SET ERROR CODE JMP SHORT J8 ; RESET_RET ;------ SEND SPECIFY COMMAND TO NEC J7: ; DRIVE_READY MOV AH,03H ; SPECIFY COMMAND CALL NEC_OUTPUT ; OUTPUT THE COMMAND MOV BX,1 ; FIRST BYTE PARM IN BLOCK CALL GET_PARM ; TO THE NEC CONTROLLER MOV BX,3 ; SECOND BYTE PARM IN BLOCK CALL GET_PARM ; TO THE NEC CONTROLLER J8: ; RESET_RET RET ; RETURN TO CALLER DISK_RESET ENDP ;------ DISKETTE STATUS ROUTINE DISK_STATUS PROC NEAR MOV AL,DISKETTE_STATUS RET DISK_STATUS ENDP ;------ DISKETTE READ DISK_READ PROC NEAR MOV AL,046H ; READ COMMAND FOR DMA J9: ; DISK_READ_CONT CALL DMA_SETUP ; SET UP THE DMA MOV AH,066H ; SET UP READ COMMAND FOR NEC CONTROLLER JMP SHORT RW_OPN ; GO DO THE OPERATION DISK_READ ENDP ;------ DISKETTE VERIFY DISK_VERF PROC NEAR MOV AL,042H ; VERIFY COMMAND FOR DMA JMP J9 ; DO AS IF DISK READ DISK_VERF ENDP ;------ DISKETTE FORMAT DISK_FORMAT PROC NEAR OR MOTOR_STATUS,80H ; INDICATE WRITE OPERATION MOV AL,04AH ; WILL WRITE TO THE DISKETTE CALL DMA_SETUP ; SET UP THE DMA MOV AH,04DH ; ESTABLISH THE FORMAT COMMAND JMP SHORT RW_OPN ; DO THE OPERATION J10: ; CONTINUATION OF RW_OPN FOR FMT MOV BX,7 ; GET THE CALL GET_PARM ; BYTES/SECTOR VALUE TO NEC MOV BX,9 ; GET THE CALL GET_PARM ; SECTORS/TRACK VALUE TO NEC MOV BX,15 ; GET THE CALL GET_PARM ; GAP LENGTH VALUE TO NEC MOV BX,17 ; GET THE FILLER BYTE JMP J16 ; TO THE CONTROLLER DISK_FORMAT ENDP ;------ DISKETTE WRITE ROUTINE DISK_WRITE PROC NEAR OR MOTOR_STATUS,80H ; INDICATE WRITE OPERATION MOV AL,04AH ; DMA WRITE COMMAND CALL DMA_SETUP MOV AH,045H ; NEC COMMAND TO WRITE TO DISKETTE DISK_WRITE ENDP ;----- ALLOW WRITE ROUTINE TO FALL INTO RW_OPN ;--------------------------------------- ; RW_OPN ; THIS ROUTINE PERFORMS THE READ/WRITE/VERIFY OPERATION ;--------------------------------------- RW_OPN PROC NEAR JNC J11 ; TEST FOR DMA ERROR MOV DISKETTE_STATUS,DMA_BOUNDARY ; SET ERROR MOV AL,0 ; NO SECTORS TRANSFERRED RET ; RETURN TO MAIN ROUTINE J11: ; DO_RW_OPN PUSH AX ; SAVE THE COMMAND ;------ TURN ON THE MOTOR AND SELECT THE DRIVE PUSH CX ; SAVE THE T/S PARMS MOV CL,DL ; GET DRIVE NUMBER AS SHIFT COUNT MOV AL,1 ; MASK FOR DETERMINING MOTOR BIT SAL AL,CL ; SHIFT THE MASK BIT CLI ; NO INTERRUPTS WHILE DETERMINING MOTOR STATUS MOV MOTOR_COUNT,0FFH ; SET LARGE COUNT DURING OPERATION TEST AL,MOTOR_STATUS ; TEST THAT MOTOR FOR OPERATING JNZ J14 ; IF RUNNING, SKIP THE WAIT AND MOTOR_STATUS,0F0H ; TURN OFF ALL MOTOR BITS OR MOTOR_STATUS,AL ; TURN ON THE CURRENT MOTOR STI ; INTERRUPTS BACK ON MOV AL,10H ; MASK BIT SAL AL,CL ; DEVELOP BIT MASK FOR MOTOR ENABLE OR AL,DL ; GET DRIVE SELECT BITS IN OR AL,0CH ; NO RESET, ENABLE DMA/INT PUSH DX ; SAVE REG MOV DX,03F2H ; CONTROL PORT ADDRESS OUT DX,AL POP DX ; RECOVER REGISTERS ;------ WAIT FOR MOTOR IF WRITE OPERATION TEST MOTOR_STATUS,80H ; IS THIS A WRITE JZ J14 ; NO, CONTINUE WITHOUT WAIT MOV BX,20 ; GET THE MOTOR WAIT CALL GET_PARM ; PARAMETER OR AH,AH ; TEST FOR NO WAIT J12: ; TEST_WAIT_TIME JZ J14 ; EXIT WITH TIME EXPIRED SUB CX,CX ; SET UP 1/8 SECOND LOOP TIME J13: LOOP J13 ; WAIT FOR THE REQUIRED TIME DEC AH ; DECREMENT TIME VALUE JMP J12 ; ARE WE DONE YET J14: ; MOTOR_RUNNING STI ; INTERRUPTS BACK ON FOR BYPASS WAIT POP CX ;------ DO THE SEEK OPERATION CALL SEEK ; MOVE TO CORRECT TRACK POP AX ; RECOVER COMMAND MOV BH,AH ; SAVE COMMAND IN BH MOV DH,0 ; SET NO SECTORS READ IN CASE OF ERROR JC J17 ; IF ERROR, THEN EXIT AFTER MOTOR OFF MOV SI,OFFSET J17 ; DUMMY RETURN ON STACK FOR NEC_OUTPUT PUSH SI ; SO THAT IT WILL RETURN TO MOTOR OFF LOCATION ;------ SEND OUT THE PARAMETERS TO THE CONTROLLER CALL NEC_OUTPUT ; OUTPUT THE OPERATION COMMAND MOV AH,[BP+1] ; GET THE CURRENT HEAD NUMBER SAL AH,1 ; MOVE IT TO BIT 2 SAL AH,1 AND AH,4 ; ISOLATE THAT BIT OR AH,DL ; OR IN THE DRIVE NUMBER CALL NEC_OUTPUT ;------ TEST FOR FORMAT COMMAND CMP BH,04DH ; IS THIS A FORMAT OPERATION JNE J15 ; NO, CONTINUE WITH R/W/V JMP J10 ; IF SO, HANDLE SPECIAL J15: MOV AH,CH ; CYLINDER NUMBER CALL NEC_OUTPUT MOV AH,[BP+1] ; HEAD NUMBER FROM STACK CALL NEC_OUTPUT MOV AH,CL ; SECTOR NUMBER CALL NEC_OUTPUT MOV BX,7 ; BYTES/SECTOR PARM FROM BLOCK CALL GET_PARM ; TO THE NEC MOV BX,9 ; EOT PARM FROM BLOCK CALL GET_PARM ; TO THE NEC MOV BX,11 ; GAP LENGTH PARM FROM BLOCK CALL GET_PARM ; TO THE NEC MOV BX,13 ; DTL PARM FROM BLOCK J16: ; RW_OPN FINISH CALL GET_PARM ; TO THE NEC POP SI ; CAN NOW DISCARD THAT DUMMY RETURN ADDRESS ;------ LET THE OPERATION HAPPEN CALL WAIT_INT ; WAIT FOR THE INTERRUPT J17: ; MOTOR_OFF JC J21 ; LOOK FOR ERROR CALL RESULTS ; GET THE NEC STATUS JC J20 ; LOOK FOR ERROR ;------ CHECK THE RESULTS RETURNED BY THE CONTROLLER CLD ; SET THE CORRECT DIRECTION MOV SI,OFFSET NEC_STATUS ; POINT TO STATUS FIELD LODS NEC_STATUS ; GET ST0 AND AL,0C0H ; TEST FOR NORMAL TERMINATION JZ J22 ; OPN_OK CMP AL,040H ; TEST FOR ABNORMAL TERMINATION JNZ J18 ; NOT ABNORMAL, BAD NEC ;------ ABNORMAL TERMINATION, FIND OUT WHY LODS NEC_STATUS ; GET ST1 SAL AL,1 ; TEST FOR EOT FOUND MOV AH,RECORD_NOT_FND JC J19 ; RW_FAIL SAL AL,1 SAL AL,1 ; TEST FOR CRC ERROR MOV AH,BAD_CRC JC J19 ; RW_FAIL SAL AL,1 ; TEST FOR DMA OVERRUN MOV AH,BAD_DMA JC J19 ; RW_FAIL SAL AL,1 SAL AL,1 ; TEST FOR RECORD NOT FOUND MOV AH,RECORD_NOT_FND JC J19 ; RW_FAIL SAL AL,1 MOV AH,WRITE_PROTECT ; TEST FOR WRITE PROTECT JC J19 ; RW_FAIL SAL AL,1 ; TEST MISSING ADDRESS MARK MOV AH,BAD_ADDR_MARK JC J19 ; RW_FAIL ;------ NEC MUST HAVE FAILED J18: ; RW_NEC_FAIL MOV AH,BAD_NEC J19: ; RW_FAIL OR DISKETTE_STATUS,AH CALL NUM_TRANS ; HOW MANY WERE REALLY TRANSFERRED J20: ; RW_ERR RET ; RETURN TO CALLER J21: ; RW_ERR_RES CALL RESULTS ; FLUSH THE RESULTS BUFFER RET ;------ OPERATION WAS SUCCESSFUL J22: ; OPN_OK CALL NUM_TRANS ; HOW MANY GOT MOVED XOR AH,AH ; NO ERRORS RET RW_OPN ENDP ;-------------------------------------------- ; NEC_OUTPUT ; THIS ROUTINE SENDS A BYTE TO THE NEC CONTROLLER ; AFTER TESTING FOR CORRECT DIRECTION AND CONTROLLER READY ; THIS ROUTINE WILL TIME OUT IF THE BYTE IS NOT ACCEPTED ; WITHIN A REASONABLE AMOUNT OF TIME, SETTING THE DISKETTE STATUS ; ON COMPLETION ; INPUT ; (AH) BYTE TO BE OUTPUT ; OUTPUT ; CY = 0 SUCCESS ; CY = 1 FAILURE -- DISKETTE STATUS UPDATED ; IF A FAILURE HAS OCCURRED, THE RETURN IS MADE ONE LEVEL ; HIGHER THAN THE CALLER OF NEC_OUTPUT ; THIS REMOVES THE REQUIREMENT OF TESTING AFTER EVERY CALL ; OF NEC_OUTPUT ; (AL) DESTROYED ;-------------------------------------------- NEC_OUTPUT PROC NEAR PUSH DX ; SAVE REGISTERS PUSH CX MOV DX,03F4H ; STATUS PORT XOR CX,CX ; COUNT FOR TIME OUT J23: IN AL,DX ; GET STATUS TEST AL,040H ; TEST DIRECTION BIT JZ J25 ; DIRECTION OK LOOP J23 J24: ; TIME_ERROR OR DISKETTE_STATUS,TIME_OUT POP CX POP DX ; SET ERROR CODE AND RESTORE REGS POP AX ; DISCARD THE RETURN ADDRESS STC ; INDICATE ERROR TO CALLER RET J25: XOR CX,CX ; RESET THE COUNT J26: IN AL,DX ; GET THE STATUS TEST AL,080H ; IS IT READY JNZ J27 ; YES, GO OUTPUT LOOP J26 ; COUNT DOWN AND TRY AGAIN JMP J24 ; ERROR CONDITION J27: ; OUTPUT MOV AL,AH ; GET BYTE TO OUTPUT MOV DX,03F5H ; DATA PORT OUT DX,AL ; OUTPUT THE BYTE POP CX ; RECOVER REGISTERS POP DX RET ; CY = 0 FROM TEST INSTRUCTION NEC_OUTPUT ENDP ;------------------------------------------ ; GET_PARM ; THIS ROUTINE FETCHES THE INDEXED POINTER FROM ; THE DISK_BASE BLOCK POINTED AT BY THE DATA ; VARIABLE DISK_POINTER ; A BYTE FROM THAT TABLE IS THEN MOVED INTO AH, ; THE INDEX OF THAT BYTE BEING THE PARM IN BX ; ENTRY -- ; BX = INDEX OF BYTE TO BE FETCHED * 2 ; IF THE LOW BIT OF BX IS ON, THE BYTE IS IMMEDIATELY ; OUTPUT TO THE NEC CONTROLLER ; EXIT -- ; AH = THAT BYTE FROM BLOCK ;-------------------------------------------- GET_PARM PROC NEAR PUSH DS ; SAVE SEGMENT SUB AX,AX ; ZERO TO AX MOV DS,AX ASSUME DS:ABS0 LDS SI,DISK_POINTER ; POINT TO BLOCK SHR BX,1 ; DIVIDE BX BY 2, AND SET FLAG FOR EXIT MOV AH,[SI+BX] ; GET THE WORD POP DS ; RESTORE SEGMENT ASSUME DS:DATA JC NEC_OUTPUT ; IF FLAG SET, OUTPUT TO CONTROLLER RET ; RETURN TO CALLER GET_PARM ENDP ;-------------------------------------------- ; SEEK ; THIS ROUTINE WILL MOVE THE HEAD ON THE NAMED DRIVE ; TO THE NAMED TRACK. IF THE DRIVE HAS NOT BEEN ACCESSED ; SINCE THE DRIVE RESET COMMAND WAS ISSUED, THE DRIVE WILL BE ; RECALIBRATED. ; INPUT ; (DL) = DRIVE TO SEEK ON ; (CH) = TRACK TO SEEK TO ; OUTPUT ; CY = 0 SUCCESS ; CY = 1 FAILURE -- DISKETTE_STATUS SET ACCORDINGLY ; (AX) DESTROYED ;-------------------------------------------- SEEK PROC NEAR MOV AL,1 ; ESTABLISH MASK FOR RECAL TEST PUSH CX ; SAVE INPUT VALUES MOV CL,DL ; GET DRIVE VALUE INTO CL ROL AL,CL ; SHIFT IT BY THE DRIVE VALUE POP CX ; RECOVER TRACK VALUE TEST AL,SEEK_STATUS ; TEST FOR RECAL REQUIRED JNZ J28 ; NO_RECAL OR SEEK_STATUS,AL ; TURN ON THE NO RECAL BIT IN FLAG MOV AH,07H ; RECALIBRATE COMMAND CALL NEC_OUTPUT MOV AH,DL CALL NEC_OUTPUT ; OUTPUT THE DRIVE NUMBER CALL CHK_STAT_2 ; GET THE INTERUPT AN SENSE INT STATUS JC J32 ; SEEK_ERROR ;----- DRIVE IS IN SYNCH WITH CONTROLLER, SEEK TO TRACK J28: MOV AH,0FH ; SEEK COMMAND TO NEC CALL NEC_OUTPUT MOV AH,DL ; DRIVE NUMBER CALL NEC_OUTPUT MOV AH,CH ; TRACK NUMBER CALL NEC_OUTPUT CALL CHK_STAT_2 ; GET ENDING INTERRUPT AND SENSE STATUS ;----- WAIT FOR HEAD SETTLE PUSHF ; SAVE STATE FLAGS MOV BX,18 ; GET HEAD SETTLE PARAMETER CALL GET_PARM PUSH CX ; SAVE REGISTER J29: ; HEAD_SETTLE MOV CX,550 ; 1 MS LOOP OR AH,AH ; TEST FOR TIME EXPIRED JZ J31 J30: LOOP J30 ; DELAY FOR 1 MS DEC AH ; DECREMENT THE COUNT JMP J29 ; DO IT SOME MORE J31: POP CX ; RECOVER STATE POPF J32: ; SEEK ERROR RET ; RETURN TO CALLER SEEK ENDP ;-------------------------------------------- ; DMA_SETUP ; THIS ROUTINE SETS UP THE DMA FOR READ/WRITE/VERIFY ; OPERATIONS. ; INPUT ; (AL) = MODE BYTE FOR THE DMA ; (ES:BX) = ADDRESS TO READ/WRITE THE DATA ; OUTPUT ; (AX) DESTROYED ;-------------------------------------------- DMA_SETUP PROC NEAR PUSH CX ; SAVE THE REGISTER OUT DMA+12,AL ; SET THE FIRST/LAST F/F OUT DMA+11,AL ; OUTPUT THE MODE BYTE MOV AX,ES ; GET THE ES VALUE MOV CL,4 ; SHIFT COUNT ROL AX,CL ; ROTATE LEFT MOV CH,AL ; GET HIGHEST NYBLE OF ES TO CH AND AL,0F0H ; ZERO THE LOW NYBBLE FROM SEGMENT ADD AX,BX ; TEST FOR CARRY FROM ADDITION JNC J33 INC CH ; CARRY MEANS HIGH 4 BITS MUST BE INC J33: PUSH AX ; SAVE START ADDRESS OUT DMA+4,AL ; OUTPUT LOW ADDRESS MOV AL,AH OUT DMA+4,AL ; OUTPUT HIGH ADDRESS MOV AL,CH ; GET HIGH 4 BITS AND AL,0FH OUT 081H,AL ; OUTPUT THE HIGH 4 BITS TO PAGE REGISTER ;------ DETERMINE COUNT MOV AH,DH ; NUMBER OF SECTORS SUB AL,AL ; TIMES 256 INTO AX SHR AX,1 ; SECTORS * 128 INTO AX PUSH AX MOV BX,6 ; GET THE BYTES/SECTOR PARM CALL GET_PARM MOV CL,AH ; USE AS SHIFT COUNT(0=128,1=256 ETC) POP AX SHL AX,CL ; MULTIPLY BY CORRECT AMOUNT DEC AX ; -1 FOR DMA VALUE PUSH AX ; SAVE COUNT VALUE OUT DMA+5,AL ; LOW BYTE OF COUNT MOV AL,AH OUT DMA+5,AL ; HIGH BYTE OF COUNT POP CX ; RECOVER COUNT VALUE POP AX ; RECOVER ADDRESS VALUE ADD AX,CX ; ADD, TEST FOR 64K OVERFLOW POP CX ; RECOVER REGISTER MOV AL,2 ; MODE FOR 8237 OUT DMA+10,AL ; INITIALIZE THE DISKETTE CHANNEL RET ; RETURN TO CALLER, CFL SET BY ABOVE IF ERROR DMA_SETUP ENDP ;--------------------------------------------- ; CHK_STAT_2 ; THIS ROUTINE HANDLES THE INTERRUPT RECEIVED AFTER ; A RECALIBRATE, SEEK, OR RESET TO THE ADAPTER. ; THE INTERRUPT IS WAITED FOR, THE INTERRUPT STATUS SENSED, ; AND THE RESULT RETURNED TO THE CALLER. ; INPUT ; NONE ; OUTPUT ; CY = 0 SUCCESS ; CY = 1 FAILURE -- ERROR IS IN DISKETTE_STATUS ; (AX) DESTROYED ;--------------------------------------------- CHK_STAT_2 PROC NEAR CALL WAIT_INT ; WAIT FOR THE INTERRUPT JC J34 ; IF ERROR, RETURN IT MOV AH,08H ; SENSE INTERRUPT STATUS COMMAND CALL NEC_OUTPUT CALL RESULTS ; READ IN THE RESULTS JC J34 ; CHK2_RETURN MOV AL,NEC_STATUS ; GET THE FIRST STATUS BYTE AND AL,060H ; ISOLATE THE BITS CMP AL,060H ; TEST FOR CORRECT VALUE JZ J35 ; IF ERROR, GO MARK IT CLC ; GOOD RETURN J34: RET ; RETURN TO CALLER J35: ; CHK2_ERROR OR DISKETTE_STATUS,BAD_SEEK STC ; ERROR RETURN CODE RET CHK_STAT_2 ENDP ;------------------------------------------ ; WAIT_INT ; THIS ROUTINE WAITS FOR AN INTERRUPT TO OCCUR ; A TIME OUT ROUTINE TAKES PLACE DURING THE WAIT, SO ; THAT AN ERROR MAY BE RETURNED IF THE DRIVE IS NOT READY ; INPUT ; NONE ; OUTPUT ; CY = 0 SUCCESS ; CY = 1 FAILURE -- DISKETTE_STATUS IS SET ACCORDINGLY ; (AX) DESTROYED ;------------------------------------------ WAIT_INT PROC NEAR STI ; TURN ON INTERRUPTS, JUST IN CASE PUSH BX PUSH CX ; SAVE REGISTERS MOV BL,2 ; CLEAR THE COUNTERS XOR CX,CX ; FOR 2 SECOND WAIT J36: TEST SEEK_STATUS,INT_FLAG ; TEST FOR INTERRUPT OCCURRING JNZ J37 LOOP J36 ; COUNT DOWN WHILE WAITING DEC BL ; SECOND LEVEL COUNTER JNZ J36 OR DISKETTE_STATUS,TIME_OUT ; NOTHING HAPPENED STC ; ERROR RETURN J37: PUSHF ; SAVE CURRENT CARRY AND SEEK_STATUS,NOT INT_FLAG ; TURN OFF INTERRUPT FLAG POPF ; RECOVER CARRY POP CX POP BX ; RECOVER REGISTERS RET ; GOOD RETURN CODE COMES FROM TEST INST WAIT_INT ENDP ;------------------------------------------- ; DISK_INT ; THIS ROUTINE HANDLES THE DISKETTE INTERRUPT ; INPUT ; NONE ; OUTPUT ; THE INTERRUPT FLAG IS SET IS SEEK_STATUS ;-------------------------------------------- DISK_INT PROC FAR STI ; RE ENABLE INTERRUPTS PUSH DS PUSH AX MOV AX,DATA MOV DS,AX OR SEEK_STATUS,INT_FLAG MOV AL,20H ; END OF INTERRUPT MARKER OUT 20H,AL ; INTERRUPT CONTROL PORT POP AX POP DS ; RECOVER SYSTEM IRET ; RETURN FROM INTERRUPT DISK_INT ENDP ;--------------------------------------------- ; RESULTS ; THIS ROUTINE WILL READ ANYTHING THAT THE NEC CONTROLLER ; HAS TO SAY FOLLOWING AN INTERRUPT. ; INPUT ; NONE ; OUTPUT ; CY = 0 SUCCESSFUL TRANSFER ; CY = 1 FAILURE -- TIME OUT IN WAITING FOR STATUS ; NEC_STATUS AREA HAS STATUS BYTE LOADED INTO IT ; (AH) DESTROYED ;-------------------------------------------- RESULTS PROC NEAR CLD MOV DI,OFFSET NEC_STATUS ; POINTER TO DATA AREA PUSH CX ; SAVE COUNTER PUSH DX PUSH BX MOV BL,7 ; MAX STATUS BYTES ;------ WAIT FOR REQUEST FOR MASTER J38: ; INPUT_LOOP XOR CX,CX ; COUNTER MOV DX,03F4H ; STATUS PORT J39: ; WAIT FOR MASTER IN AL,DX ; GET STATUS TEST AL,080H ; MASTER READY JNZ J40A ; TEST_DIR LOOP J39 ; WAIT MASTER OR DISKETTE_STATUS,TIME_OUT J40: ; RESULTS_ERROR STC ; SET ERROR RETURN POP BX POP DX POP CX RET ;------ TEST THE DIRECTION BIT J40A: IN AL,DX ; GET STATUS REG AGAIN TEST AL,040H ; TEST DIRECTION BIT JNZ J42 ; OK TO READ STATUS J41: ; NEC_FAIL OR DISKETTE_STATUS,BAD_NEC JMP J40 ; RESULTS ERROR ;------ READ IN THE STATUS J42: ; INPUT STATUS INC DX ; POINT AT DATA PORT IN AL,DX ; GET THE DATA MOV [DI],AL ; STORE THE BYTE INC DI ; INCREMENT THE POINTER MOV CX,10 ; LOOP TO KILL TIME FOR NEC J43: LOOP J43 DEC DX ; POINT AT STATUS PORT IN AL,DX ; GET STATUS TEST AL,010H ; TEST FOR NEC STILL BUSY JZ J44 ; RESULTS DONE DEC BL ; DECREMENT THE STATUS COUNTER JNZ J38 ; GO BACK FOR MORE JMP J41 ; CHIP HAS FAILED ;------ RESULT OPERATION IS DONE J44: POP BX POP DX POP CX ; RECOVER REGISTERS RET ; GOOD RETURN CODE FROM TEST INST ;-------------------------------------------- ; NUM_TRANS ; THIS ROUTINE CALCULATES THE NUMBER OF SECTORS THAT ; WERE ACTUALLY TRANSFERRED TO/FROM THE DISKETTE ; INPUT ; (CH) = CYLINDER OF OPERATION ; (CL) = START SECTOR OF OPERATION ; OUTPUT ; (AL) = NUMBER ACTUALLY TRANSFERRED ; NO OTHER REGISTERS MODIFIED ;------------------------------------------- NUM_TRANS PROC NEAR MOV AL,NEC_STATUS+3 ; GET CYLINDER ENDED UP ON CMP AL,CH ; SAME AS THE STARTED MOV AL,NEC_STATUS+5 ; GET ENDING SECTOR JZ J45 ; IF ON SAME CYL, THEN NO ADJUST MOV BX,8 CALL GET_PARM ; GET EOT VALUE MOV AL,AH ; INTO AL INC AL ; USE EOT+1 FOR CALCULATION J45: SUB AL,CL ; SUBTRACT START FROM END RET NUM_TRANS ENDP RESULTS ENDP ;-------------------------------------------- ; DISK_BASE ; THIS IS THE SET OF PARAMETERS REQUIRED FOR ; DISKETTE OPERATION, THEY ARE POINTED AT BY THE ; DATA VARIABLE DISK_POINTER. TO MODIFY THE PARAMETERS, ; BUILD ANOTHER PARAMETER BLOCK AND POINT AT IT ;-------------------------------------------- DISK_BASE LABEL BYTE DB 11001111B ; SRT=C, HD UNLOAD=0F - 1ST SPECIFY BYTE DB 2 ; HD LOAD=1, MODE=DMA - 2ND SPECIFY BYTE DB MOTOR_WAIT ; WAIT AFTER OPN TIL MOTOR OFF DB 2 ; 512 BYTES/SECTOR DB 8 ; EOT (LAST SECTOR ON TRACK) DB 02AH ; GAP LENGTH DB 0FFH ; DTL DB 050H ; GAP LENGTH FOR FORMAT DB 0F6H ; FILL BYTE FOR FORMAT DB 25 ; HEAD SETTLE TIME (MILLISECONDS) DB 4 ; MOTOR START TIME (1/8 SECONDS) ;--- INT 17 --------------------------------- ;PRINTER_IO ; THIS ROUTINE PROVIDES COMMUNICATION WITH THE PRINTER ; (AH)=0 PRINT THE CHARACTER IN (AL) ; ON RETURN, AH=1 IF CHARACTER COULD NOT BE PRINTED (TIME OUT) ; OTHER BITS SET AS ON NORMAL STATUS CALL ; (AH)=1 INITIALIZE THE PRINTER PORT ; RETURNS WITH (AH) SET WITH PRINTER STATUS ; (AH)=2 READ THE PRINTER STATUS INTO (AH) ; 7 6 5 4 3 2-1 0 ; | | | | | | _ TIME OUT ; | | | | | _ UNUSED ; | | | | _ 1 = I/O ERROR ; | | | _ 1 = SELECTED ; | | _ 1 = OUT OF PAPER ; | _ 1 = ACKNOWLEDGE ; _ 1 = BUSY ; ; (DX) = PRINTER TO BE USED (0,1,2) CORRESPONDING TO ACTUAL VALUES ; IN PRINTER_BASE AREA ; DATA AREA PRINTER BASE CONTAINS THE BASE ADDRESS OF THE PRINTER CARD(S) ; AVAILABLE (LOCATED AT BEGINNING OF DATA SEGMENT, 408H ABSOLUTE, 3 WORDS) ;REGISTERS AH IS MODIFIED ; ALL OTHERS UNCHANGED ;-------------------------------------------- ASSUME CS:CODE,DS:DATA PRINTER_IO PROC FAR STI ; INTERRUPTS BACK PUSH DS ; SAVE SEGMENT PUSH DX PUSH SI PUSH CX PUSH BX MOV SI,DATA MOV DS,SI ; ESTABLISH PRINTER SEGMENT MOV SI,DX ; GET PRINTER PARM SHL SI,1 ; WORD OFFSET INTO TABLE MOV DX,PRINTER_BASE[SI] ; GET BASE ADDRESS FOR PRINTER CARD OR DX,DX ; TEST DX FOR ZERO, INDICATING NO PRINTER JZ B1 ; RETURN OR AH,AH ; TEST FOR (AH)=0 JZ B2 ; PRINT_AL DEC AH ; TEST FOR (AH)=1 JZ B8 ; INIT_PRT DEC AH ; TEST FOR (AH)=2 JZ B5 ; PRINTER STATUS B1: ; RETURN POP BX POP CX POP SI ; RECOVER REGISTERS POP DX ; RECOVER REGISTERS POP DS IRET ;------ PRINT THE CHARACTER IN (AL) B2: PUSH AX ; SAVE VALUE TO PRINT MOV BL,10 ; TIME OUT VALUE XOR CX,CX ; ESTABLISH SHIFT COUNT OUT DX,AL ; OUTPUT CHAR TO PORT INC DX ; POINT TO STATUS PORT B3: ; WAIT_BUSY IN AL,DX ; GET STATUS MOV AH,AL ; STATUS TO AH ALSO TEST AL,80H ; IS THE PRINTER CURRENTLY BUSY JNZ B4 ; OUT_STROBE LOOP B3 ; DECREMENT COUNT ON TIME OUT DEC BL JNZ B3 ; WAIT FOR NOT BUSY OR AH,1 ; SET ERROR FLAG AND AH,0F9H ; TURN OFF THE OTHER BITS JMP SHORT B7 ; RETURN WITH ERROR FLAG SET B4: ; OUT_STROBE MOV AL,0DH ; SET THE STROBE HIGH INC DX ; STROBE IS BIT 0 OF PORT C OF 8255 OUT DX,AL MOV AL,0CH ; SET THE STROBE LOW OUT DX,AL POP AX ; RECOVER THE OUTPUT CHAR ;------ PRINTER STATUS B5: PUSH AX ; SAVE AL REG B6: MOV DX,PRINTER_BASE[SI] INC DX IN AL,DX ; GET PRINTER STATUS MOV AH,AL AND AH,0F8H ; TURN OFF USED BITS B7: ; STATUS_SET POP DX ; RECOVER AL REG MOV AL,DL ; GET CHARACTER INTO AL XOR AH,48H ; FLIP A COUPLE OF BITS JMP B1 ; RETURN FROM ROUTINE ;------ INITIALIZE THE PRINTER PORT B8: PUSH AX ; SAVE AL ADD DX,2 ; POINT TO OUTPUT PORT MOV AL,8 ; SET INIT LINE LOW OUT DX,AL MOV AX,1000 B9: ; INIT_LOOP DEC AX ; LOOP FOR RESET TO TAKE JNZ B9 ; INIT_LOOP MOV AL,0CH ; NO INTERRUPTS, NON AUTO LF, INIT HIGH OUT DX,AL JMP B6 ; PRT_STATUS_1 PRINTER_IO ENDP ;--- INT 10 --------------------------------- ; VIDEO_IO ; THESE ROUTINES PROVIDE THE CRT INTERFACE ; THE FOLLOWING FUNCTIONS ARE PROVIDED: ; (AH)=0 SET MODE (AL) CONTAINS MODE VALUE ; (AL)=0 40X25 BW (POWER ON DEFAULT) ; (AL)=1 40X25 COLOR ; (AL)=2 80X25 BW ; (AL)=3 80X25 COLOR ; GRAPHICS MODES ; (AL)=4 320X200 COLOR ; (AL)=5 320X200 BW ; (AL)=6 640X200 BW ; CRT MODE = 7 80X25 B&W CARD (USED INTERNAL TO VIDEO ONLY) ; *** NOTE BW MODES OPERATE SAME AS COLOR MODES, BUT COLOR ; BURST IS NOT ENABLED ; (AH)=1 SET CURSOR TYPE ; (CH) = BITS 4-0 = START LINE FOR CURSOR ; ** HARDWARE WILL ALWAYS CAUSE BLINK ; ** SETTING BIT 5 OR 6 WILL CAUSE ERRATIC BLINKING ; OR NO CURSOR AT ALL ; (CL) = BITS 4-0 = END LINE FOR CURSOR ; (AH)=2 SET CURSOR POSITION ; (DH,DL) = ROW,COLUMN (0,0) IS UPPER LEFT ; (DH) = PAGE NUMBER (MUST BE 0 FOR GRAPHICS MODES) ; (AH)=3 READ CURSOR POSITION ; (BH) = PAGE NUMBER (MUST BE 0 FOR GRAPHICS MODES) ; ON EXIT (DH,DL) = ROW,COLUMN OF CURRENT CURSOR ; (CH,CL) = CURSOR MODE CURRENTLY SET ; (AH)=4 READ LIGHT PEN POSITION ; ON EXIT: ; (AH) = 0 -- LIGHT PEN SWITCH NOT DOWN/NOT TRIGGERED ; (AH) = 1 -- VALID LIGHT PEN VALUE IN REGISTERS ; (DH,DL) = ROW, COLUMN OF CHARACTER LP POSN ; (CH) = RASTER LINE (0-199) ; (BX) = PIXEL COLUMN (0-319,639) ; (AH)=5 SELECT ACTIVE DISPLAY PAGE (VALID ONLY FOR ALPHA MODES) ; (AL)=NEW PAGE VALUE (0-7 FOR MODES 0&1, 0-3 FOR MODES 2&3) ; (AH)=6 SCROLL ACTIVE PAGE UP ; (AL) = NUMBER OF LINES, INPUT LINES BLANKED AT BOTTOM OF WINDOW ; AL = 0 MEANS BLANK ENTIRE WINDOW ; (CH,CL) = ROW,COLUMN OF UPPER LEFT CORNER OF SCROLL ; (DH,DL) = ROW,COLUMN OF LOWER RIGHT CORNER OF SCROLL ; (BH) = ATTRIBUTE TO BE USED ON BLANK LINE ; (AH)=7 SCROLL ACTIVE PAGE DOWN ; (AL) = NUMBER OF LINES, INPUT LINES BLANKED AT TOP OF WINDOW ; AL = 0 MEANS BLANK ENTIRE WINDOW ; (CH,CL) = ROW,COLUMN OF UPPER LEFT CORNER OF SCROLL ; (DH,DL) = ROW,COLUMN OF LOWER RIGHT CORNER OF SCROLL ; (BH) = ATTRIBUTE TO BE USED ON BLANK LINE ; ; CHARACTER HANDLING ROUTINES ; ; (AH) = 8 READ ATTRIBUTE/CHARACTER AT CURRENT CURSOR POSITION ; (BH) = DISPLAY PAGE (VALID FOR ALPHA MODES ONLY) ; ON EXIT: ; (AL) = CHAR READ ; (AH) = ATTRIBUTE OF CHARACTER READ (ALPHA MODES ONLY) ; (AH) = 9 WRITE ATTRIBUTE/CHARACTER AT CURRENT CURSOR POSITION ; (BH) = DISPLAY PAGE (VALID FOR ALPHA MODES ONLY) ; (CX) = COUNT OF CHARACTERS TO WRITE ; (AL) = CHAR TO WRITE ; (BL) = ATTRIBUTE OF CHARACTER (ALPHA)/COLOR OF CHAR (GRAPHICS) ; SEE NOTE ON WRITE DOT FOR BIT 7 OF BL = 1. ; (AH) = 10 WRITE CHARACTER ONLY AT CURRENT CURSOR POSITION ; (BH) = DISPLAY PAGE (VALID FOR ALPHA MODES ONLY) ; (CX) = COUNT OF CHARACTERS TO WRITE ; (AL) = CHAR TO WRITE ; FOR READ/WRITE CHARACTER INTERFACE WHILE IN GRAPHICS MODE, THE ; CHARACTERS ARE FORMED FROM A CHARACTER GENERATOR IMAGE ; MAINTAINED IN THE SYSTEM ROM. ONLY THE 1ST 128 CHARS ; ARE CONTAINED THERE. TO READ/WRITE THE SECOND 128 CHARS. ; THE USER MUST INITIALIZE THE POINTER AT INTERRUPT 1FH ; (LOCATION 0007CH) TO POINT TO THE 1K BYTE TABLE CONTAINING ; THE CODE POINTS FOR THE SECOND 128 CHARS (128-255). ; FOR WRITE CHARACTER INTERFACE IN GRAPHICS MODE, THE REPLICATION FACTOR ; CONTAINED IN (CX) ON ENTRY WILL PRODUCE VALID RESULTS ONLY ; FOR CHARACTERS CONTAINED ON THE SAME ROW. CONTINUATION TO ; SUCCEEDING LINES WILL NOT PRODUCE CORRECTLY. ; ; GRAPHICS INTERFACE ; (AH) = 11 SET COLOR PALETTE ; (BH) = PALLETTE COLOR ID BEING SET (0-127) ; (BL) = COLOR VALUE TO BE USED WITH THAT COLOR ID ; NOTE: FOR THE CURRENT COLOR CARD, THIS ENTRY POINT HAS ; MEANING ONLY FOR 320X200 GRAPHICS. ; COLOR ID = 0 SELECTS THE BACKGROUND COLOR (0-15) ; COLOR ID = 1 SELECTS THE PALLETTE TO BE USED: ; 0 = GREEN(1)/RED(2)/YELLOW(3) ; 1 = CYAN(1)/MAGENTA(2)/WHITE(3) ; IN 40X25 OR 80X25 ALPHA MODES, THE VALUE SET FOR ; PALLETTE COLOR 0 INDICATES THE BORDER COLOR ; TO BE USED (VALUES 0-31, WHERE 16-31 SELECT THE ; HIGH INTENSITY BACKGROUND SET. ; (AH) = 12 WRITE DOT ; (DX) = ROW NUMBER ; (CX) = COLUMN NUMBER ; (AL) = COLOR VALUE ; IF BIT 7 OF AL = 1, THEN THE COLOR VALUE IS EXCLUSIVE ; OR'D WITH THE CURRENT CONTENTS OF THE DOT ; (AH) = 13 READ DOT ; (DX) = ROW NUMBER ; (CX) = COLUMN NUMBER ; (AL) RETURNS THE DOT READ ; ; ASCII TELETYPE ROUTINE FOR OUTPUT ; ; (AH) = 14 WRITE TELETYPE ; (AL) = CHAR TO WRITE ; (BL) = FOREGROUND COLOR IN GRAPHICS MODE ; (BH) = DISPLAY PAGE IN ALPHA MODE ; NOTE -- SCREEN WIDTH IS CONTROLLED BY PREVIOUS MODE SET ; ; (AH) = 15 CURRENT VIDEO STATE ; RETURNS THE CURRENT VIDEO STATE ; (AL) = MODE CURRENTLY SET (SEE AH=0 FOR EXPLANATION) ; (AH) = NUMBER OF CHARACTER COLUMNS ON SCREEN ; (BH) = CURRENT ACTIVE DISPLAY PAGE ; ; CS,SS,DS,ES,BX,CX,DX PRESERVED DURING CALL ; ALL OTHERS DESTROYED ;-------------------------------------------- ASSUME CS:CODE,DS:DATA,ES:VIDEO_RAM M1 LABEL WORD ; TABLE OF ROUTINES WITHIN VIDEO I/O DW OFFSET SET_MODE DW OFFSET SET_CTYPE DW OFFSET SET_CPOS DW OFFSET READ_CURSOR DW OFFSET READ_LPEN DW OFFSET ACT_DISP_PAGE DW OFFSET SCROLL_UP DW OFFSET SCROLL_DOWN DW OFFSET READ_AC_CURRENT DW OFFSET WRITE_AC_CURRENT DW OFFSET WRITE_C_CURRENT DW OFFSET SET_COLOR DW OFFSET WRITE_DOT DW OFFSET READ_DOT DW OFFSET WRITE_TTY DW OFFSET VIDEO_STATE M1L EQU $-M1 VIDEO_IO PROC NEAR STI ; INTERRUPTS BACK ON CLD ; SET DIRECTION FORWARD PUSH ES PUSH DS ; SAVE SEGMENT REGISTERS PUSH DX PUSH CX PUSH BX PUSH SI PUSH DI PUSH AX ; SAVE AX VALUE MOV AL,AH ; GET INTO LOW BYTE XOR AH,AH ; ZERO TO HIGH BYTE SAL AX,1 ; *2 FOR TABLE LOOKUP MOV SI,AX ; PUT INTO SI FOR BRANCH CMP AX,M1L ; TEST FOR WITHIN RANGE JB M2 ; BRANCH AROUND BRANCH POP AX ; THROW AWAY THE PARAMETER JMP VIDEO_RETURN ; DO NOTHING IF NOT IN RANGE M2: MOV AX,DATA MOV DS,AX MOV AX,0B800H ; SEGMENT FOR COLOR CARD MOV DI,EQUIP_FLAG ; GET EQUIPMENT SETTING AND DI,30H ; ISOLATE CRT SWITCHES CMP DI,30H ; IS SETTING FOR BW CARD? JNE M3 MOV AX,0B000H ; SEGMENT FOR BW CARD M3: MOV ES,AX ; SET UP TO POINT AT VIDEO RAM AREAS POP AX ; RECOVER VALUE MOV AH,CRT_MODE ; GET CURRENT MODE INTO AH JMP WORD PTR CS:[SI+OFFSET M1] VIDEO_IO ENDP ;------------------------------------------ ; SET_MODE ; THIS ROUTINE INITIALIZES THE ATTACHMENT TO ; THE SELECTED MODE. THE SCREEN IS BLANKED. ; INPUT ; (AL) = MODE SELECTED (RANGE 0-9) ; OUTPUT ; NONE ;------------------------------------------ ;------ TABLES FOR USE IN SETTING OF MODE VIDEO_PARMS LABEL BYTE ;------ INIT_TABLE DB 38H,28H,2DH,0AH,1FH,6,19H ; SET UP FOR 40X25 DB 1CH,2,7,6,7 DB 0,0,0,0 M4 EQU $-VIDEO_PARMS DB 71H,50H,5AH,0AH,1FH,6,19H ; SET UP FOR 80X25 DB 1CH,2,7,6,7 DB 0,0,0,0 DB 38H,28H,2DH,0AH,7FH,6,64H ; SET UP FOR GRAPHICS DB 70H,2,1,6,7 DB 0,0,0,0 DB 61H,50H,52H,0FH,19H,6,19H ; SET UP FOR 80X25 B&W CARD DB 19H,2,0DH,0BH,0CH DB 0,0,0,0 M5 LABEL WORD ; TABLE OF REGEN LENGTHS DW 2048 ; 40X25 DW 4096 ; 80X25 DW 16384 ; GRAPHICS DW 16384 ; ;------ COLUMNS M6 LABEL BYTE DB 40,40,80,80,40,40,80,80 ;------ C_REG_TAB M7 LABEL BYTE ; TABLE OF MODE SETS DB 2CH,28H,2DH,29H,2AH,2EH,1EH,29H SET_MODE PROC NEAR MOV DX,03D4H ; ADDRESS OF COLOR CARD MOV BL,0 ; MODE SET FOR COLOR CARD CMP DI,30H ; IS BW CARD INSTALLED JNE M8 ; OK WITH COLOR MOV AL,7 ; INDICATE BW CARD MODE MOV DX,03B4H ; ADDRESS OF BW CARD INC BL ; MODE SET FOR BW CARD M8: MOV AH,AL ; SAVE MODE IN AH MOV CRT_MODE,AL ; SAVE IN GLOBAL VARIABLE MOV ADDR_6845,DX ; SAVE ADDRESS OF BASE PUSH DS ; SAVE POINTER TO DATA SEGMENT PUSH AX ; SAVE MODE PUSH DX ; SAVE OUTPUT PORT VALUE ADD DX,4 ; POINT TO CONTROL REGISTER MOV AL,BL ; GET MODE SET FOR CARD OUT DX,AL ; RESET VIDEO POP DX ; BACK TO BASE REGISTER SUB AX,AX ; SET UP FOR ABS0 SEGMENT MOV DS,AX ; ESTABLISH VECTOR TABLE ADDRESSING ASSUME DS:ABS0 LDS BX,PARM_PTR ; GET POINTER TO VIDEO PARMS POP AX ; RECOVER PARMS ASSUME DS:CODE MOV CX,M4 ; LENGTH OF EACH ROW OF TABLE CMP AH,2 ; DETERMINE WHICH ONE TO USE JC M9 ; MODE IS 0 OR 1 ADD BX,CX ; MOVE TO NEXT ROW OF INIT_TABLE CMP AH,4 JC M9 ; MODE IS 2 OR 3 ADD BX,CX ; MOVE TO GRAPHICS ROW OF INIT_TABLE CMP AH,7 JC M9 ; MODE IS 4,5, OR 6 ADD BX,CX ; MOVE TO BW CARD ROW OF INIT_TABLE ;------ BX POINTS TO CORRECT ROW OF INITIALIZATION TABLE M9: ; OUT_INIT PUSH AX ; SAVE MODE IN AH XOR AH,AH ; AH WILL SERVE AS REGISTER NUMBER DURING LOOP ;------ LOOP THROUGH TABLE, OUTPUTTING REG ADDRESS, THEN VALUE FROM TABLE M10: ; INIT LOOP MOV AL,AH ; GET 6845 REGISTER NUMBER OUT DX,AL INC DX ; POINT TO DATA PORT INC AH ; NEXT REGISTER VALUE MOV AL,[BX] ; GET TABLE VALUE OUT DX,AL ; OUT TO CHIP INC BX ; NEXT IN TABLE DEC DX ; BACK TO POINTER REGISTER LOOP M10 ; DO THE WHOLE TABLE POP AX ; GET MODE BACK POP DS ; RECOVER SEGMENT VALUE ASSUME DS:DATA ;------ FILL REGEN AREA WITH BLANK XOR DI,DI ; SET UP POINTER FOR REGEN MOV CRT_START,DI ; START ADDRESS SAVED IN GLOBAL MOV ACTIVE_PAGE,0 ; SET PAGE VALUE MOV CX,8192 ; NUMBER OF WORDS IN COLOR CARD CMP AH,4 ; TEST FOR GRAPHICS JC M12 ; NO_GRAPHICS_INIT CMP AH,7 ; TEST FOR BW CARD JE M11 ; BW_CARD_INIT XOR AX,AX ; FILL FOR GRAPHICS MODE JMP SHORT M13 ; CLEAR_BUFFER M11: ; BW_CARD_INIT MOV CX,2048 ; BUFFER SIZE ON BW CARD M12: ; NO_GRAPHICS_INIT MOV AX,' '+7*256 ; FILL CHAR FOR ALPHA M13: ; CLEAR BUFFER REP STOSW ; FILL THE REGEN BUFFER WITH BLANKS ;------ ENABLE VIDEO AND CORRECT PORT SETTING MOV CURSOR_MODE,67H ; SET CURRENT CURSOR MODE MOV AL,CRT_MODE ; GET THE MODE XOR AH,AH ; INTO AX REGISTER MOV SI,AX ; TABLE POINTER, INDEXED BY MODE MOV DX,ADDR_6845 ; PREPARE TO OUTPUT TO VIDEO ENABLE PORT ADD DX,4 MOV AL,CS:[SI+OFFSET M7] OUT DX,AL ; SET VIDEO ENABLE PORT MOV CRT_MODE_SET,AL ; SAVE THAT VALUE ;------ DETERMINE NUMBER OF COLUMNS, BOTH FOR ENTIRE DISPLAY ;------ AND THE NUMBER TO BE USED FOR TTY INTERFACE MOV AL,CS:[SI + OFFSET M6] XOR AH,AH MOV CRT_COLS,AX ; NUMBER OF COLUMNS IN THIS SCREEN ;------ SET CURSOR POSITIONS AND SI,0EH ; WORD OFFSET INTO CLEAR LENGTH TABLE MOV CX,CS:[SI+OFFSET M5] ; LENGTH TO CLEAR MOV CRT_LEN,CX ; SAVE LENGTH OF CRT -- NOT USED FOR BW MOV CX,8 ; CLEAR ALL CURSOR POSITIONS MOV DI,OFFSET CURSOR_POSN PUSH DS ; ESTABLISH SEGMENT POP ES ; ADDRESSING XOR AX,AX REP STOSW ; FILL WITH ZEROES ;------ SET UP OVERSCAN REGISTER INC DX ; SET OVERSCAN PORT TO A DEFAULT MOV AL,30H ; VALUE OF 30H FOR ALL MODES EXCEPT 640X200 CMP CRT_MODE,6 ; SEE IF THE MODE IS 640X200 BW JNZ M14 ; IF IT ISNT 640X200, THEN GOTO REGULAR MOV AL,3FH ; IF IT IS 640X200, THEN PUT IN 3FH M14: OUT DX,AL ; OUTPUT THE CORRECT VALUE TO 3D9 PORT MOV CRT_PALLETTE,AL ; SAVE THE VALUE FOR FUTURE USE ;------ NORMAL RETURN FROM ALL VIDEO RETURNS VIDEO_RETURN: POP DI POP SI POP BX M15: ; VIDEO_RETURN_C POP CX POP DX POP DS POP ES ; RECOVER SEGMENTS IRET ; ALL DONE SET_MODE ENDP ;-------------------------------------------- ; SET_CTYPE ; THIS ROUTINE SETS THE CURSOR VALUE ; INPUT ; (CX) HAS CURSOR VALUE CH-START LINE, CL-STOP LINE ; OUTPUT ; NONE ;-------------------------------------------- SET_CTYPE PROC NEAR MOV AH,10 ; 6845 REGISTER FOR CURSOR SET MOV CURSOR_MODE,CX ; SAVE IN DATA AREA CALL M16 ; OUTPUT CX REG JMP VIDEO_RETURN ;------ THIS ROUTINE OUTPUTS THE CX REGISTER TO THE 6845 REGS NAMED IN AH M16: MOV DX,ADDR_6845 ; ADDRESS REGISTER MOV AL,AH ; GET VALUE OUT DX,AL ; REGISTER SET INC DX ; DATA REGISTER MOV AL,CH ; DATA OUT DX,AL DEC DX MOV AL,AH INC AL ; POINT TO OTHER DATA REGISTER OUT DX,AL ; SET FOR SECOND REGISTER INC DX MOV AL,CL ; SECOND DATA VALUE OUT DX,AL RET ; ALL DONE SET_CTYPE ENDP ;-------------------------------------------- ; SET_CPOS ; THIS ROUTINE SETS THE CURRENT CURSOR POSITION TO THE ; NEW X-Y VALUES PASSED ; INPUT ; DX - ROW, COLUMN OF NEW CURSOR ; BH - DISPLAY PAGE OF CURSOR ; OUTPUT ; CURSOR IS SET AT 6845 IF DISPLAY PAGE IS CURRENT DISPLAY ;-------------------------------------------- SET_CPOS PROC NEAR MOV CL,BH XOR CH,CH ; ESTABLISH LOOP COUNT SAL CX,1 ; WORD OFFSET MOV SI,CX ; USE INDEX REGISTER MOV [SI+OFFSET CURSOR_POSN],DX ; SAVE THE POINTER CMP ACTIVE_PAGE,BH JNZ M17 ; SET_CPOS_RETURN MOV AX,DX ; GET ROW/COLUMN TO AX CALL M18 ; CURSOR_SET M17: ; SET_CPOS_RETURN JMP VIDEO_RETURN SET_CPOS ENDP ;------ SET CURSOR POSITION, AX HAS ROW/COLUMN FOR CURSOR M18 PROC NEAR CALL POSITION ; DETERMINE LOCATION IN REGEN BUFFER MOV CX,AX ADD CX,CRT_START ; ADD IN THE START ADDRESS FOR THIS PAGE SAR CX,1 ; DIVIDE BY 2 FOR CHAR ONLY COUNT MOV AH,14 ; REGISTER NUMBER FOR CURSOR CALL M16 ; OUTPUT THE VALUE TO THE 6845 RET M18 ENDP ;-------------------------------------------- ; READ_CURSOR ; THIS ROUTINE READS THE CURRENT CURSOR VALUE FROM THE ; 6845, FORMATS IT, AND SENDS IT BACK TO THE CALLER ; INPUT ; BH - PAGE OF CURSOR ; OUTPUT ; DX - ROW, COLUMN OF THE CURRENT CURSOR POSITION ; CX - CURRENT CURSOR MODE ;------------------------------------------- READ_CURSOR PROC NEAR MOV BL,BH XOR BH,BH SAL BX,1 ; WORD OFFSET MOV DX,[BX+OFFSET CURSOR_POSN] MOV CX,CURSOR_MODE POP DI POP SI POP BX POP AX ; DISCARD SAVED CX AND DX POP AX POP DS POP ES IRET READ_CURSOR ENDP ;-------------------------------------------- ; ACT_DISP_PAGE ; THIS ROUTINE SETS THE ACTIVE DISPLAY PAGE, ALLOWING ; THE FULL USE OF THE RAM SET ASIDE FOR THE VIDEO ATTACHMENT ; INPUT ; AL HAS THE NEW ACTIVE DISPLAY PAGE ; OUTPUT ; THE 6845 IS RESET TO DISPLAY THAT PAGE ;-------------------------------------------- ACT_DISP_PAGE PROC NEAR MOV ACTIVE_PAGE,AL ; SAVE ACTIVE PAGE VALUE MOV CX,CRT_LEN ; GET SAVED LENGTH OF REGEN BUFFER CBW ; CONVERT AL TO WORD PUSH AX ; SAVE PAGE VALUE MUL CX ; DISPLAY PAGE TIMES REGEN LENGTH MOV CRT_START,AX ; SAVE START ADDRESS FOR LATER REQUIREMENTS MOV CX,AX ; START ADDRESS TO CX SAR CX,1 ; DIVIDE BY 2 FOR 6845 HANDLING MOV AH,12 ; 6845 REGISTER FOR START ADDRESS CALL M16 POP BX ; RECOVER PAGE VALUE SAL BX,1 ; *2 FOR WORD OFFSET MOV AX,[BX+OFFSET CURSOR_POSN] ; GET CURSOR FOR THIS PAGE CALL M18 ; SET THE CURSOR POSITION JMP VIDEO_RETURN ACT_DISP_PAGE ENDP ;-------------------------------------------- ; SET_COLOR ; THIS ROUTINE WILL ESTABLISH THE BACKGROUND COLOR, THE OVERSCAN COLOR, ; AND THE FOREGROUND COLOR SET FOR MEDIUM RESOLUTION GRAPHICS ; INPUT ; (BH) HAS COLOR ID ; IF BH=0, THE BACKGROUND COLOR VALUE IS SET ; FROM THE LOW BITS OF BL (0-31) ; IF BH=1, THE PALLETTE SELECTION IS MADE ; BASED ON THE LOW BIT OF BL: ; 0 = GREEN, RED, YELLOW FOR COLORS 1,2,3 ; 1 = BLUE, CYAN, MAGENTA FOR COLORS 1,2,3 ; (BL) HAS THE COLOR VALUE TO BE USED ; OUTPUT ; THE COLOR SELECTION IS UPDATED ;-------------------------------------------- SET_COLOR PROC NEAR MOV DX,ADDR_6845 ; I/O PORT FOR PALETTE ADD DX,5 ; OVERSCAN PORT MOV AL,CRT_PALLETTE ; GET THE CURRENT PALLETTE VALUE OR BH,BH ; IS THIS COLOR 0? JNZ M20 ; OUTPUT COLOR 1 ;------ HANDLE COLOR 0 BY SETTING THE BACKGROUND COLOR AND AL,0E0H ; TURN OFF LOW 5 BITS OF CURRENT AND BL,01FH ; TURN OFF HIGH 3 BITS OF INPUT VALUE OR AL,BL ; PUT VALUE INTO REGISTER M19: ; OUTPUT THE PALLETTE OUT DX,AL ; OUTPUT COLOR SELECTION TO 3D9 PORT MOV CRT_PALLETTE,AL ; SAVE THE COLOR VALUE JMP VIDEO_RETURN ;------ HANDLE COLOR 1 BY SELECTING THE PALLETTE TO BE USED M20: AND AL,0DFH ; TURN OFF PALLETTE SELECT BIT SHR BL,1 ; TEST THE LOW ORDER BIT OF BL JNC M19 ; ALREADY DONE OR AL,20H ; TURN ON PALLETTE SELECT BIT JMP M19 ; GO DO IT SET_COLOR ENDP ;-------------------------------------------- ;VIDEO_STATE ; RETURNS THE CURRENT VIDEO STATE IN AX ; AH = NUMBER OF COLUMNS ON THE SCREEN ; AL = CURRENT VIDEO MODE ; BH = CURRENT ACTIVE PAGE ;------------------------------------------- VIDEO_STATE PROC NEAR MOV AH,BYTE PTR CRT_COLS ; GET NUMBER OF COLUMNS MOV AL,CRT_MODE ; CURRENT MODE MOV BH,ACTIVE_PAGE ; GET CURRENT ACTIVE PAGE POP DI ; RECOVER REGISTERS POP SI ; POP CX ; DISCARD SAVED BX JMP M15 ; RETURN TO CALLER VIDEO_STATE ENDP ;----------------------------------- ; POSITION ; THIS SERVICE ROUTINE CALCULATES THE REGEN BUFFER ADDRESS ; OF A CHARACTER IN THE ALPHA MODE ; INPUT ; AX = ROW, COLUMN POSITION ; OUTPUT ; AX = OFFSET OF CHAR POSITION IN REGEN BUFFER ;------------------------------------ POSITION PROC NEAR PUSH BX ; SAVE REGISTER MOV BX,AX MOV AL,AH ; ROWS TO AL MUL BYTE PTR CRT_COLS ; DETERMINE BYTES TO ROW XOR BH,BH ADD AX,BX ; ADD IN COLUMN VALUE SAL AX,1 ; * 2 FOR ATTRIBUTE BYTES POP BX RET POSITION ENDP ;------------------------------------------ ; SCROLL_UP ; THIS ROUTINE MOVES A BLOCK OF CHARACTERS UP ; ON THE SCREEN ; INPUT ; (AH) = CURRENT CRT MODE ; (AL) = NUMBER OF ROWS TO SCROLL ; (CX) = ROW/COLUMN OF UPPER LEFT CORNER ; (DX) = ROW/COLUMN OF LOWER RIGHT CORNER ; (BH) = ATTRIBUTE TO BE USED ON BLANKED LINE ; (DS) = DATA SEGMENT ; (ES) = REGEN BUFFER SEGMENT ; OUTPUT ; NONE -- THE REGEN BUFFER IS MODIFIED ;------------------------------------------- ASSUME CS:CODE,DS:DATA,ES:DATA SCROLL_UP PROC NEAR MOV BL,AL ; SAVE LINE COUNT IN BL CMP AH,4 ; TEST FOR GRAPHICS MODE JC N1 ; HANDLE SEPARATELY CMP AH,7 ; TEST FOR BW CARD JE N1 JMP GRAPHICS_UP N1: ; UP_CONTINUE PUSH BX ; SAVE FILL ATTRIBUTE IN BH MOV AX,CX ; UPPER LEFT POSITION CALL SCROLL_POSITION ; DO SETUP FOR SCROLL JZ N7 ; BLANK_FIELD ADD SI,AX ; FROM ADDRESS MOV AH,DH ; # ROWS IN BLOCK SUB AH,BL ; # ROWS TO BE MOVED N2: ; ROW_LOOP CALL N10 ; MOVE ONE ROW ADD SI,BP ADD DI,BP ; POINT TO NEXT LINE IN BLOCK DEC AH ; COUNT OF LINES TO MOVE JNZ N2 ; ROW_LOOP N3: ; CLEAR_ENTRY POP AX ; RECOVER ATTRIBUTE IN AH MOV AL,' ' ; FILL WITH BLANKS N4: ; CLEAR_LOOP CALL N11 ; CLEAR THE ROW ADD DI,BP ; POINT TO NEXT LINE DEC BL ; COUNTER OF LINES TO SCROLL JNZ N4 ; CLEAR_LOOP N5: ; SCROLL_END MOV AX,DATA ; GET LOCATION MOV DS,AX CMP CRT_MODE,7 ; IS THIS THE BLACK AND WHITE CARD JE N6 ; IF SO, SKIP THE MODE RESET MOV AL,CRT_MODE_SET ; GET THE VALUE OF THE MODE SET MOV DX,03D8H ; ALWAYS SET COLOR CARD PORT OUT DX,AL N6: ; VIDEO_RET_HERE JMP VIDEO_RETURN N7: ; BLANK_FIELD MOV BL,DH ; GET ROW COUNT JMP N3 ; GO CLEAR THAT AREA SCROLL_UP ENDP ;----- HANDLE COMMON SCROLL SET UP HERE SCROLL_POSITION PROC NEAR CMP CRT_MODE,2 ; TEST FOR SPECIAL CASE HERE JB N9 ; HAVE TO HANDLE 80X25 SEPARATELY CMP CRT_MODE,3 JA N9 ;------ 80X25 COLOR CARD SCROLL PUSH DX MOV DX,3DAH ; GUARANTEED TO BE COLOR CARD HERE PUSH AX N8: ; WAIT_DISP_ENABLE IN AL,DX ; GET PORT TEST AL,8 ; WAIT FOR VERTICAL RETRACE JZ N8 ; WAIT_DISP_ENABLE MOV AL,25H MOV DX,03D8H OUT DX,AL ; TURN OFF VIDEO POP AX ; DURING VERTICAL RETRACE POP DX N9: CALL POSITION ; CONVERT TO REGEN POINTER ADD AX,CRT_START ; OFFSET OF ACTIVE PAGE MOV DI,AX ; TO ADDRESS FOR SCROLL MOV SI,AX ; FROM ADDRESS FOR SCROLL SUB DX,CX ; DX = #ROWS, #COLS IN BLOCK INC DH INC DL ; INCREMENT FOR 0 ORIGIN XOR CH,CH ; SET HIGH BYTE OF COUNT TO ZERO MOV BP,CRT_COLS ; GET NUMBER OF COLUMNS IN DISPLAY ADD BP,BP ; TIMES 2 FOR ATTRIBUTE BYTE MOV AL,BL ; GET LINE COUNT MUL BYTE PTR CRT_COLS ; DETERMINE OFFSET TO FROM ADDRESS ADD AX,AX ; *2 FOR ATTRIBUTE BYTE PUSH ES ; ESTABLISH ADDRESSING TO REGEN BUFFER POP DS ; FOR BOTH POINTERS CMP BL,0 ; 0 SCROLL MEANS BLANK FIELD RET ; RETURN WITH FLAGS SET SCROLL_POSITION ENDP ;----- MOVE_ROW N10 PROC NEAR MOV CL,DL ; GET # OF COLS TO MOVE PUSH SI PUSH DI ; SAVE START ADDRESS REP MOVSW ; MOVE THAT LINE ON SCREEN POP DI POP SI ; RECOVER ADDRESSES RET N10 ENDP ;------ CLEAR_ROW N11 PROC NEAR MOV CL,DL ; GET # COLUMNS TO CLEAR PUSH DI REP STOSW ; STORE THE FILL CHARACTER POP DI RET N11 ENDP ;----------------------------------- ; SCROLL_DOWN ; THIS ROUTINE MOVES THE CHARACTERS WITHIN A DEFINED ; BLOCK DOWN ON THE SCREEN, FILLING THE TOP LINES ; WITH A DEFINED CHARACTER ; INPUT ; (AH) = CURRENT CRT MODE ; (AL) = NUMBER OF LINES TO SCROLL ; (CX) = UPPER LEFT CORNER OF REGION ; (DX) = LOWER RIGHT CORNER OF REGION ; (BH) = FILL CHARACTER ; (DS) = DATA SEGMENT ; (ES) = REGEN SEGMENT ; OUTPUT ; NONE -- SCREEN IS SCROLLED ;----------------------------------- SCROLL_DOWN PROC NEAR STD ; DIRECTION FOR SCROLL MOV BL,AL ; LINE COUNT TO BL CMP AH,4 ; TEST FOR GRAPHICS JC N12 CMP AH,7 ; TEST FOR BW CARD JE N12 JMP GRAPHICS_DOWN N12: ; CONTINUE DOWN PUSH BX ; SAVE ATTRIBUTE IN BH MOV AX,DX ; LOWER RIGHT CORNER CALL SCROLL_POSITION ; GET REGEN LOCATION JZ N16 SUB SI,AX ; SI IS FROM ADDRESS MOV AH,DH ; GET TOTAL # ROWS SUB AH,BL ; COUNT TO MOVE IN SCROLL N13: CALL N10 ; MOVE ONE ROW SUB SI,BP SUB DI,BP DEC AH JNZ N13 N14: POP AX ; RECOVER ATTRIBUTE IN AH MOV AL,' ' N15: CALL N11 ; CLEAR ONE ROW SUB DI,BP ; GO TO NEXT ROW DEC BL JNZ N15 JMP N5 ; SCROLL_END N16: MOV BL,DH JMP N14 SCROLL_DOWN ENDP ;------------------------------------------ ; READ_AC_CURRENT ; THIS ROUTINE READS THE ATTRIBUTE AND CHARACTER AT THE CURRENT ; CURSOR POSITION AND RETURNS THEM TO THE CALLER ; INPUT ; (AH) = CURRENT CRT MODE ; (BH) = DISPLAY PAGE (ALPHA MODES ONLY) ; (DS) = DATA SEGMENT ; (ES) = REGEN SEGMENT ; OUTPUT ; (AL) = CHAR READ ; (AH) = ATTRIBUTE READ ;------------------------------------------ ASSUME CS:CODE,DS:DATA,ES:DATA READ_AC_CURRENT PROC NEAR CMP AH,4 ; IS THIS GRAPHICS JC P1 CMP AH,7 ; IS THIS BW CARD JE P1 JMP GRAPHICS_READ P1: ; READ_AC_CONTINUE CALL FIND_POSITION MOV SI,BX ; ESTABLISH ADDRESSING IN SI ;------ WAIT FOR HORIZONTAL RETRACE MOV DX,ADDR_6845 ; GET BASE ADDRESS ADD DX,6 ; POINT AT STATUS PORT PUSH ES ; POP DS ; GET SEGMENT FOR QUICK ACCESS P2: ; WAIT FOR RETRACE LOW IN AL,DX ; GET STATUS TEST AL,1 ; IS HORZ RETRACE LOW JNZ P2 ; WAIT UNTIL IT IS CLI ; NO MORE INTERRUPTS P3: ; WAIT FOR RETRACE HIGH IN AL,DX ; GET STATUS TEST AL,1 ; IS IT HIGH JZ P3 ; WAIT UNTIL IT IS LODSW ; GET THE CHAR/ATTR JMP VIDEO_RETURN READ_AC_CURRENT ENDP FIND_POSITION PROC NEAR MOV CL,BH ; DISPLAY PAGE TO CX XOR CH,CH MOV SI,CX ; MOVE TO SI FOR INDEX SAL SI,1 ; * 2 FOR WORD OFFSET MOV AX,[SI+OFFSET CURSOR_POSN] ; GET ROW/COLUMN OF THAT PAGE XOR BX,BX ; SET START ADDRESS TO ZERO JCXZ P5 ; NO_PAGE P4: ; PAGE_LOOP ADD BX,CRT_LEN ; LENGTH OF BUFFER LOOP P4 P5: ; NO_PAGE CALL POSITION ; DETERMINE LOCATION IN REGEN ADD BX,AX ; ADD TO START OF REGEN RET FIND_POSITION ENDP ;----------------------------------------- ; WRITE_AC_CURRENT ; THIS ROUTINE WRITES THE ATTRIBUTE AND CHARACTER AT ; THE CURRENT CURSOR POSITION ; INPUT ; (AH) = CURRENT CRT MODE ; (BH) = DISPLAY PAGE ; (CX) = COUNT OF CHARACTERS TO WRITE ; (AL) = CHAR TO WRITE ; (BL) = ATTRIBUTE OF CHAR TO WRITE ; (DS) = DATA SEGMENT ; (ES) = REGEN SEGMENT ; OUTPUT ; NONE ;------------------------------------------ WRITE_AC_CURRENT PROC NEAR CMP AH,4 ; IS THIS GRAPHICS JC P6 CMP AH,7 ; IS THIS BW CARD JE P6 JMP GRAPHICS_WRITE P6: ; WRITE_AC_CONTINUE MOV AH,BL ; GET ATTRIBUTE TO AH PUSH AX ; SAVE ON STACK PUSH CX ; SAVE WRITE COUNT CALL FIND_POSITION MOV DI,BX ; ADDRESS TO DI REGISTER POP CX ; WRITE COUNT POP BX ; CHARACTER IN BX REG P7: ; WRITE_LOOP ;------ WAIT FOR HORIZONTAL RETRACE MOV DX,ADDR_6845 ; GET BASE ADDRESS ADD DX,6 ; POINT AT STATUS PORT P8: IN AL,DX ; GET STATUS TEST AL,1 ; IS IT LOW JNZ P8 ; WAIT UNTIL IT IS CLI ; NO MORE INTERRUPTS P9: IN AL,DX ; GET STATUS TEST AL,1 ; IS IT HIGH JZ P9 ; WAIT UNTIL IT IS MOV AX,BX ; RECOVER THE CHAR/ATTR STOSW ; PUT THE CHAR/ATTR STI ; INTERRUPTS BACK ON LOOP P7 ; AS MANY TIMES AS REQUESTED JMP VIDEO_RETURN WRITE_AC_CURRENT ENDP ;----------------------------------------- ; WRITE_C_CURRENT ; THIS ROUTINE WRITES THE CHARACTER AT ; THE CURRENT CURSOR POSITION, ATTRIBUTE UNCHANGED ; INPUT ; (AH) = CURRENT CRT MODE ; (BH) = DISPLAY PAGE ; (CX) = COUNT OF CHARACTERS TO WRITE ; (AL) = CHAR TO WRITE ; (DS) = DATA SEGMENT ; (ES) = REGEN SEGMENT ;OUTPUT ; NONE ;------------------------------------------ WRITE_C_CURRENT PROC NEAR CMP AH,4 ; IS THIS GRAPHICS JC P10 CMP AH,7 ; IS THIS BW CARD JE P10 JMP GRAPHICS_WRITE P10: PUSH AX ; SAVE ON STACK PUSH CX ; SAVE WRITE COUNT CALL FIND_POSITION MOV DI,BX ; ADDRESS TO DI POP CX ; WRITE COUNT POP BX ; BL HAS CHAR TO WRITE P11: ; WRITE_LOOP ;------ WAIT FOR HORIZONTAL RETRACE MOV DX,ADDR_6845 ; GET BASE ADDRESS ADD DX,6 ; POINT AT STATUS PORT P12: IN AL,DX ; GET STATUS TEST AL,1 ; IS IT LOW JNZ P12 ; WAIT UNTIL IT IS CLI ; NO MORE INTERRUPTS P13: IN AL,DX ; GET STATUS TEST AL,1 ; IS IT HIGH JZ P13 ; WAIT UNTIL IT IS MOV AL,BL ; RECOVER CHAR STOSB ; PUT THE CHAR/ATTR INC DI ; BUMP POINTER PAST ATTRIBUTE LOOP P11 ; AS MANY TIMES AS REQUESTED JMP VIDEO_RETURN WRITE_C_CURRENT ENDP ;-------------------------------------------- ; READ DOT -- WRITE DOT ; THESE ROUTINES WILL WRITE A DOT, OR READ THE ; DOT AT THE INDICATED LOCATION ; ENTRY -- ; DX = ROW (0-199) (THE ACTUAL VALUE DEPENDS ON THE MODE) ; CX = COLUMN (0-639) ( THE VALUES ARE NOT RANGE CHECKED ) ; AL = DOT VALUE TO WRITE (1,2 OR 4 BITS DEPENDING ON MODE, ; REQ'D FOR WRITE DOT ONLY, RIGHT JUSTIFIED) ; BIT 7 OF AL = 1 INDICATES XOR THE VALUE INTO THE LOCATION ; DS = DATA SEGMENT ; ES = REGEN SEGMENT ; ; EXIT ; AL = DOT VALUE READ, RIGHT JUSTIFIED, READ ONLY ;-------------------------------------------- ASSUME CS:CODE,DS:DATA,ES:DATA READ_DOT PROC NEAR CALL R3 ; DETERMINE BYTE POSITION OF DOT MOV AL,ES:[SI] ; GET THE BYTE AND AL,AH ; MASK OFF THE OTHER BITS IN THE BYTE SHL AL,CL ; LEFT JUSTIFY THE VALUE MOV CL,DH ; GET NUMBER OF BITS IN RESULT ROL AL,CL ; RIGHT JUSTIFY THE RESULT JMP VIDEO_RETURN ; RETURN FROM VIDEO IO READ_DOT ENDP WRITE_DOT PROC NEAR PUSH AX ; SAVE DOT VALUE PUSH AX ; TWICE CALL R3 ; DETERMINE BYTE POSITION OF THE DOT SHR AL,CL ; SHIFT TO SET UP THE BITS FOR OUTPUT AND AL,AH ; STRIP OFF THE OTHER BITS MOV CL,ES:[SI] ; GET THE CURRENT BYTE POP BX ; RECOVER XOR FLAG TEST BL,80H ; IS IT ON JNZ R2 ; YES, XOR THE DOT NOT AH ; SET THE MASK TO REMOVE THE INDICATED BITS AND CL,AH OR AL,CL ; OR IN THE NEW VALUE OF THOSE BITS R1: ; FINISH_DOT MOV ES:[SI],AL ; RESTORE THE BYTE IN MEMORY POP AX JMP VIDEO_RETURN ; RETURN FROM VIDEO IO R2: ; XOR_DOT XOR AL,CL ; EXCLUSIVE OR THE DOTS JMP R1 ; FINISH UP THE WRITING WRITE_DOT ENDP ;-------------------------------------------- ; THIS SUBROUTINE DETERMINES THE REGEN BYTE LOCATION OF THE ; INDICATED ROW COLUMN VALUE IN GRAPHICS MODE. ; ENTRY -- ; DX = ROW VALUE (0-199) ; CX = COLUMN VALUE (0-639) ; EXIT -- ; SI = OFFSET INTO REGEN BUFFER FOR BYTE OF INTEREST ; AH = MASK TO STRIP OFF THE BITS OF INTEREST ; CL = BITS TO SHIFT TO RIGHT JUSTIFY THE MASK IN AH ; DH = BITS IN RESULT ;-------------------------------------------- R3 PROC NEAR PUSH BX ; SAVE BX DURING OPERATION PUSH AX ; WILL SAVE AL DURING OPERATION ;------ DETERMINE 1ST BYTE IN INDICATED ROW BY MULTIPLYING ROW VALUE BY 40 ;------ ( LOW BIT OF ROW DETERMINES EVEN/ODD, 80 BYTES/ROW MOV AL,40 PUSH DX ; SAVE ROW VALUE AND DL,0FEH ; STRIP OFF ODD/EVEN BIT MUL DL ; AX HAS ADDRESS OF 1ST BYTE OF INDICATED ROW POP DX ; RECOVER IT TEST DL,1 ; TEST FOR EVEN/ODD JZ R4 ; JUMP IF EVEN ROW ADD AX,2000H ; OFFSET TO LOCATION OF ODD ROWS R4: ; EVEN_ROW MOV SI,AX ; MOVE POINTER TO SI POP AX ; RECOVER AL VALUE MOV DX,CX ; COLUMN VALUE TO DX ;------ DETERMINE GRAPHICS MODE CURRENTLY IN EFFECT ; SET UP THE REGISTERS ACCORDING TO THE MODE ; CH = MASK FOR LOW OF COLUMN ADDRESS (7/3 FOR HIGH/MED RES) ; CL = # OF ADDRESS BITS IN COLUMN VALUE (3/2 FOR H/M) ; BL = MASK TO SELECT BITS FROM POINTED BYTE (80H/C0H FOR H/M) ; BH = NUMBER OF VALID BITS IN POINTED BYTE (1/2 FOR H/M) MOV BX,2C0H MOV CX,302H ; SET PARMS FOR MED RES CMP CRT_MODE,6 JC R5 ; HANDLE IF MED RES MOV BX,180H MOV CX,703H ; SET PARMS FOR HIGH RES ;------ DETERMINE BIT OFFSET IN BYTE FROM COLUMN MASK R5: AND CH,DL ; ADDRESS OF PEL WITHIN BYTE TO CH ;------ DETERMINE BYTE OFFSET FOR THIS LOCATION IN COLUMN SHR DX,CL ; SHIFT BY CORRECT AMOUNT ADD SI,DX ; INCREMENT THE POINTER MOV DH,BH ; GET THE # OF BITS IN RESULT TO DH ;------ MULTIPLY BH (VALID BITS IN BYTE) BY CH (BIT OFFSET) SUB CL,CL ; ZERO INTO STORAGE LOCATION R6: ROR AL,1 ; LEFT JUSTIFY THE VALUE IN AL (FOR WRITE) ADD CL,CH ; ADD IN THE BIT OFFSET VALUE DEC BH ; LOOP CONTROL JNZ R6 ; ON EXIT, CL HAS SHIFT COUNT TO RESTORE BITS MOV AH,BL ; GET MASK TO AH SHR AH,CL ; MOVE THE MASK TO CORRECT LOCATION POP BX ; RECOVER REG RET ; RETURN WITH EVERYTHING SET UP R3 ENDP ;-------------------------------------------- ; SCROLL UP ; THIS ROUTINE SCROLLS UP THE INFORMATION ON THE CRT ; ENTRY -- ; CH,CL = UPPER LEFT CORNER OF REGION TO SCROLL ; DH,DL = LOWER RIGHT CORNER OF REGION TO SCROLL ; BOTH OF THE ABOVE ARE IN CHARACTER POSITIONS ; BH = FILL VALUE FOR BLANKED LINES ; AL = # LINES TO SCROLL (AL=0 MEANS BLANK THE ENTIRE FIELD) ; DS = DATA SEGMENT ; ES = REGEN SEGMENT ; EXIT -- ; NOTHING, THE SCREEN IS SCROLLED ;-------------------------------------------- GRAPHICS_UP PROC NEAR MOV BL,AL ; SAVE LINE COUNT IN BL MOV AX,CX ; GET UPPER LEFT POSITION INTO AX REG ;------ USE CHARACTER SUBROUTINE FOR POSITIONING ;------ ADDRESS RETURNED IS MULTIPLIED BY 2 FROM CORRECT VALUE CALL GRAPH_POSN MOV DI,AX ; SAVE RESULT AS DESTINATION ADDRESS ;------ DETERMINE SIZE OF WINDOW SUB DX,CX ADD DX,101H ; ADJUST VALUES SAL DH,1 ; MULTIPLY # ROWS BY 4 SINCE 8 VERT DOTS/CHAR SAL DH,1 ; AND EVEN/ODD ROWS ;------ DETERMINE CRT MODE CMP CRT_MODE,6 ; TEST FOR MEDIUM RES JNC R7 ; FIND_SOURCE ;------ MEDIUM RES UP SAL DL,1 ; # COLUMNS * 2, SINCE 2 BYTES/CHAR SAL DI,1 ; OFFSET *2 SINCE 2 BYTES/CHAR ;------ DETERMINE THE SOURCE ADDRESS IN THE BUFFER R7: ; FIND_SOURCE PUSH ES ; GET SEGMENTS BOTH POINTING TO REGEN POP DS SUB CH,CH ; ZERO TO HIGH OF COUNT REG SAL BL,1 ; MULTIPLY NUMBER OF LINES BY 4 SAL BL,1 JZ R11 ; IF ZERO, THEN BLANK ENTIRE FIELD MOV AL,BL ; GET NUMBER OF LINES IN AL MOV AH,80 ; 80 BYTES MUL AH ; DETERMINE OFFSET TO SOURCE MOV SI,DI ; SET UP SOURCE ADD SI,AX ; ADD IN OFFSET TO IT MOV AH,DH ; NUMBER OF ROWS IN FIELD SUB AH,BL ; DETERMINE NUMBER TO MOVE ;------ LOOP THROUGH, MOVING ONE ROW AT A TIME, BOTH EVEN AND ODD FIELDS R8: ; ROW_LOOP CALL R17 ; MOVE ONE ROW SUB SI,2000H-80 ; MOVE TO NEXT ROW SUB DI,2000H-80 DEC AH ; NUMBER OF ROWS TO MOVE JNZ R8 ; CONTINUE TILL ALL MOVED ;------ FILL IN THE VACATED LINE(S) R9: ; CLEAR_ENTRY MOV AL,BH ; ATTRIBUTE TO FILL WITH R10: CALL R18 ; CLEAR THAT ROW SUB DI,2000H-80 ; POINT TO NEXT LINE DEC BL ; NUMBER OF LINES TO FILL JNZ R10 ; CLEAR_LOOP JMP VIDEO_RETURN ; EVERYTHING DONE R11: ; BLANK_FIELD MOV BL,DH ; SET BLANK COUNT TO EVERYTHING IN FIELD JMP R9 ; CLEAR THE FIELD GRAPHICS_UP ENDP ;-------------------------------------------- ; SCROLL DOWN ; THIS ROUTINE SCROLLS DOWN THE INFORMATION ON THE CRT ; ENTRY -- ; CH,CL = UPPER LEFT CORNER OF REGION TO SCROLL ; DH,DL = LOWER RIGHT CORNER OF REGION TO SCROLL ; BOTH OF THE ABOVE ARE IN CHARACTER POSITIONS ; BH = FILL VALUE FOR BLANKED LINES ; AL = # LINES TO SCROLL (AL=0 MEANS BLANK THE ENTIRE FIELD) ; DS = DATA SEGMENT ; ES = REGEN SEGMENT ; EXIT -- ; NOTHING, THE SCREEN IS SCROLLED ;--------------------------------------------- GRAPHICS_DOWN PROC NEAR STD ; SET DIRECTION MOV BL,AL ; SAVE LINE COUNT IN BL MOV AX,DX ; GET LOWER RIGHT POSITION INTO AX REG ;------ USE CHARACTER SUBROUTINE FOR POSITIONING ;------ ADDRESS RETURNED IS MULTIPLIED BY 2 FROM CORRECT VALUE CALL GRAPH_POSN MOV DI,AX ; SAVE RESULT AS DESTINATION ADDRESS ;------ DETERMINE SIZE OF WINDOW SUB DX,CX ADD DX,101H ; ADJUST VALUES SAL DH,1 ; MULTIPLY # ROWS BY 4 SINCE 8 VERT DOTS/CHAR SAL DH,1 ; AND EVEN/ODD ROWS ;------ DETERMINE CRT MODE CMP CRT_MODE,6 ; TEST FOR MEDIUM RES JNC R12 ; FIND_SOURCE_DOWN ;------ MEDIUM RES DOWN SAL DL,1 ; # COLUMNS * 2, SINCE 2 BYTES/CHAR (OFFSET OK) SAL DI,1 ; OFFSET *2 SINCE 2 BYTES/CHAR INC DI ; POINT TO LAST BYTE ;------ DETERMINE THE SOURCE ADDRESS IN THE BUFFER R12: ; FIND_SOURCE_DOWN PUSH ES ; BOTH SEGMENTS TO REGEN POP DS SUB CH,CH ; ZERO TO HIGH OF COUNT REG ADD DI,240 ; POINT TO LAST ROW OF PIXELS SAL BL,1 ; MULTIPLY NUMBER OF LINES BY 4 SAL BL,1 JZ R16 ; IF ZERO, THEN BLANK ENTIRE FIELD MOV AL,BL ; GET NUMBER OF LINES IN AL MOV AH,80 ; 80 BYTES/ROW MUL AH ; DETERMINE OFFSET TO SOURCE MOV SI,DI ; SET UP SOURCE SUB SI,AX ; SUBTRACT THE OFFSET MOV AH,DH ; NUMBER OF ROWS IN FIELD SUB AH,BL ; DETERMINE NUMBER TO MOVE ;------ LOOP THROUGH, MOVING ONE ROW AT A TIME, BOTH EVEN AND ODD FIELDS R13: ; ROW_LOOP_DOWN CALL R17 ; MOVE ONE ROW SUB SI,2000H+80 ; MOVE TO NEXT ROW SUB DI,2000H+80 DEC AH ; NUMBER OF ROWS TO MOVE JNZ R13 ; CONTINUE TILL ALL MOVED ;------ FILL IN THE VACATED LINE(S) R14: ; CLEAR_ENTRY_DOWN MOV AL,BH ; ATTRIBUTE TO FILL WITH R15: ; CLEAR_LOOP_DOWN CALL R18 ; CLEAR A ROW SUB DI,2000H+80 ; POINT TO NEXT LINE DEC BL ; NUMBER OF LINES TO FILL JNZ R15 ; CLEAR_LOOP_DOWN CLD ; RESET THE DIRECTION FLAG JMP VIDEO_RETURN ; EVERYTHING DONE R16: ; BLANK_FIELD_DOWN MOV BL,DH ; SET BLANK COST TO EVERYTHING IN FIELD JMP R14 ; CLEAR THE FIELD GRAPHICS_DOWN ENDP ;------ ROUTINE TO MOVE ONE ROW OF INFORMATION R17 PROC NEAR MOV CL,DL ; NUMBER OF BYTES IN THE ROW PUSH SI PUSH DI ; SAVE POINTERS REP MOVSB ; MOVE THE EVEN FIELD POP DI POP SI ADD SI,2000H ADD DI,2000H ; POINT TO THE ODD FIELD PUSH SI PUSH DI ; SAVE THE POINTERS MOV CL,DL ; COUNT BACK REP MOVSB ; MOVE THE ODD FIELD POP DI POP SI ; POINTERS BACK RET ; RETURN TO CALLER R17 ENDP ;------ CLEAR A SINGLE ROW R18 PROC NEAR MOV CL,DL ; NUMBER OF BYTES IN FIELD PUSH DI ; SAVE POINTER REP STOSB ; STORE THE NEW VALUE POP DI ; POINTER BACK ADD DI,2000H ; POINT TO ODD FIELD PUSH DI MOV CL,DL REP STOSB ; FILL THE ODD FIELD POP DI RET ; RETURN TO CALLER R18 ENDP ;-------------------------------------------- ; GRAPHICS WRITE ; THIS ROUTINE WRITES THE ASCII CHARACTER TO THE CURRENT ; POSITION ON THE SCREEN. ; ENTRY -- ; AL = CHARACTER TO WRITE ; BL = COLOR ATTRIBUTE TO BE USED FOR FOREGROUND COLOR ; IF BIT 7 IS SET, THE CHAR IS XOR'D INTO THE REGEN BUFFER ; (0 IS USED FOR THE BACKGROUND COLOR) ; CX = NUMBER OF CHARS TO WRITE ; DS = DATA SEGMENT ; ES = REGEN SEGMENT ; EXIT -- ; NOTHING IS RETURNED ; ; GRAPHICS READ ; THIS ROUTINE READS THE ASCII CHARACTER AT THE CURRENT CURSOR ; POSITION ON THE SCREEN BY MATCHING THE DOTS ON THE SCREEN TO THE ; CHARACTER GENERATOR CODE POINTS ; ENTRY -- ; NONE (0 IS ASSUMED AS THE BACKGROUND COLOR) ; EXIT -- ; AL = CHARACTER READ AT THAT POSITION (0 RETURNED IF NONE FOUND) ; ; FOR BOTH ROUTINES, THE IMAGES USED TO FORM CHARS ARE CONTAINED IN ROM ; FOR THE 1ST 128 CHARS. TO ACCESS CHARS IN THE SECOND HALF, THE USER ; MUST INITIALIZE THE VECTOR AT INTERRUPT 1FH (LOCATION 0007CH) TO ; POINT TO THE USER SUPPLIED TABLE OF GRAPHIC IMAGES (8X8 BOXES). ; FAILURE TO DO SO WILL CAUSE IN STRANGE RESULTS ;-------------------------------------------- ASSUME CS:CODE,DS:DATA,ES:DATA GRAPHICS_WRITE PROC NEAR MOV AH,0 ; ZERO TO HIGH OF CODE POINT PUSH AX ; SAVE CODE POINT VALUE ;------ DETERMINE POSITION IN REGEN BUFFER TO PUT CODE POINTS CALL S26 ; FIND LOCATION IN REGEN BUFFER MOV DI,AX ; REGEN POINTER IN DI ;------ DETERMINE REGION TO GET CODE POINTS FROM POP AX ; RECOVER CODE POINT CMP AL,80H ; IS IT IN SECOND HALF JAE S1 ; YES ;------ IMAGE IS IN FIRST HALF, CONTAINED IN ROM MOV SI,0FA6EH ; OFFSET CRT_CHAR_GEN-OFFSET OF IMAGES PUSH CS ; SAVE SEGMENT ON STACK JMP SHORT S2 ; DETERMINE_MODE ;------ IMAGE IS IN SECOND HALF, IN USER RAM S1: ; EXTEND_CHAR SUB AL,80H ; ZERO ORIGIN FOR SECOND HALF PUSH DS ; SAVE DATA POINTER SUB SI,SI MOV DS,SI ; ESTABLISH VECTOR ADDRESSING ASSUME DS:ABS0 LDS SI,EXT_PTR ; GET THE OFFSET OF THE TABLE MOV DX,DS ; GET THE SEGMENT OF THE TABLE ASSUME DS:DATA POP DS ; RECOVER DATA SEGMENT PUSH DX ; SAVE TABLE SEGMENT ON STACK ;------ DETERMINE GRAPHICS MODE IN OPERATION S2: ; DETERMINE_MODE SAL AX,1 ; MULTIPLY CODE POINT SAL AX,1 ; VALUE BY 8 SAL AX,1 ADD SI,AX ; SI HAS OFFSET OF DESIRED CODES CMP CRT_MODE,6 POP DS ; RECOVER TABLE POINTER SEGMENT JC S7 ; TEST FOR MEDIUM RESOLUTION MODE ;------ HIGH RESOLUTION MODE S3: ; HIGH_CHAR PUSH DI ; SAVE REGEN POINTER PUSH SI ; SAVE CODE POINTER MOV DH,4 ; NUMBER OF LINES THROUGH LOOP S4: LODSB ; GET BYTE FROM CODE POINTS TEST BL,80H ; SHOULD WE USE THE FUNCTION JNZ S6 ; TO PUT CHAR IN STOSB ; STORE IN REGEN BUFFER LODSB S5: ; MOV ES:[DI+2000H-1],AL ; STORE IN SECOND HALF ADD DI,79 ; MOVE TO NEXT ROW IN REGEN DEC DH ; DONE WITH LOOP JNZ S4 POP SI POP DI ; RECOVER REGEN POINTER INC DI ; POINT TO NEXT CHAR POSITION LOOP S3 ; MORE CHARS TO WRITE JMP VIDEO_RETURN S6: XOR AL,ES:[DI] ; EXCLUSIVE OR WITH CURRENT STOSB ; STORE THE CODE POINT LODSB ; AGAIN FOR ODD FIELD XOR AL,ES:[DI+2000H-1] ; JMP S5 ; BACK TO MAINSTREAM ;------ MEDIUM RESOLUTION WRITE S7: ; MED_RES_WRITE MOV DL,BL ; SAVE HIGH COLOR BIT SAL DI,1 ; OFFSET*2 SINCE 2 BYTES/CHAR CALL S19 ; EXPAND BL TO FULL WORD OF COLOR S8: ; MED_CHAR PUSH DI ; SAVE REGEN POINTER PUSH SI ; SAVE THE CODE POINTER MOV DH,4 ; NUMBER OF LOOPS S9: LODSB ; GET CODE POINT CALL S21 ; DOUBLE UP ALL THE BITS AND AX,BX ; CONVERT THEM TO FOREGROUND COLOR ( 0 BACK ) TEST DL,80H ; IS THIS XOR FUNCTION JZ S10 ; NO, STORE IT IN AS IT IS XOR AH,ES:[DI] ; DO FUNCTION WITH HALF XOR AL,ES:[DI+1] ; AND WITH OTHER HALF S10: ; MOV ES:[DI],AH ; STORE FIRST BYTE MOV ES:[DI+1],AL ; STORE SECOND BYTE LODSB ; GET CODE POINT CALL S21 AND AX,BX ; CONVERT TO COLOR TEST DL,80H ; AGAIN, IS THIS XOR FUNCTION JZ S11 ; NO, JUST STORE THE VALUES XOR AH,ES:[DI+2000H] ; FUNCTION WITH FIRST HALF XOR AL,ES:[DI+2001H] ; AND WITH SECOND HALF S11: ; MOV ES:[DI+2000H],AH MOV ES:[DI+2000H+1],AL ; STORE IN SECOND PORTION OF BUFFER ADD DI,80 ; POINT TO NEXT LOCATION DEC DH JNZ S9 ; KEEP GOING POP SI ; RECOVER CODE POINTER POP DI ; RECOVER REGEN POINTER ADD DI,2 ; POINT TO NEXT CHAR POSITION LOOP S8 ; MORE TO WRITE JMP VIDEO_RETURN GRAPHICS_WRITE ENDP ;----------------------------------------------- ; GRAPHICS READ ;----------------------------------------------- GRAPHICS_READ PROC NEAR CALL S26 ; CONVERTED TO OFFSET IN REGEN MOV SI,AX ; SAVE IN SI SUB SP,8 ; ALLOCATE SPACE TO SAVE THE READ CODE POINTER MOV BP,SP ; POINTER TO SAVE AREA ;------ DETERMINE GRAPHICS MODES CMP CRT_MODE,6 PUSH ES POP DS ; POINT TO REGEN SEGMENT JC S13 ; MEDIUM RESOLUTION ;------ HIGH RESOLUTION READ ;------ GET VALUES FROM REGEN BUFFER AND CONVERT TO CODE POINT MOV DH,4 ; NUMBER OF PASSES S12: MOV AL,[SI] ; GET FIRST BYTE MOV [BP],AL ; SAVE IN STORAGE AREA INC BP ; NEXT LOCATION MOV AL,[SI+2000H] ; GET LOWER REGION BYTE MOV [BP],AL ; ADJUST AND STORE INC BP ADD SI,80 ; POINTER INTO REGEN DEC DH ; LOOP CONTROL JNZ S12 ; DO IT SOME MORE JMP S15 ; GO MATCH THE SAVED CODE POINTS ;------ MEDIUM RESOLUTION READ S13: ; MED_RES_READ SAL SI,1 ; OFFSET*2 SINCE 2 BYTES/CHAR MOV DH,4 ; NUMBER OF PASSES S14: CALL S23 ; GET PAIR BYTES FROM REGEN INTO SINGLE SAVE ADD SI,2000H ; GO TO LOWER REGION CALL S23 ; GET THIS PAIR INTO SAVE SUB SI,2000H-80 ; ADJUST POINTER BACK INTO UPPER DEC DH JNZ S14 ; KEEP GOING UNTIL ALL 8 DONE ;-------- SAVE AREA HAS CHARACTER IN IT, MATCH IT S15: ; FIND_CHAR MOV DI,0FA6EH ; OFFSET CRT_CHAR_GEN-ESTABLISH ADDRESSING PUSH CS POP ES ; CODE POINTS IN CS SUB BP,8 ; ADJUST POINTER TO BEGINNING OF SAVE AREA MOV SI,BP CLD ; ENSURE DIRECTION MOV AL,0 ; CURRENT CODE POINT BEING MATCHED S16: PUSH SS ; ESTABLISH ADDRESSING TO STACK POP DS ; FOR THE STRING COMPARE MOV DX,128 ; NUMBER TO TEST AGAINST S17: PUSH SI ; SAVE SAVE AREA POINTER PUSH DI ; SAVE CODE POINTER MOV CX,8 ; NUMBER OF BYTES TO MATCH REPE CMPSB ; COMPARE THE 8 BYTES POP DI ; RECOVER THE POINTERS POP SI JZ S18 ; IF ZERO FLAG SET, THEN MATCH OCCURRED INC AL ; NO MATCH, MOVE ON TO NEXT ADD DI,8 ; NEXT CODE POINT DEC DX ; LOOP CONTROL JNZ S17 ; DO ALL OF THEM ;------ CHAR NOT MATCHED, MIGHT BE IN USER SUPPLIED SECOND HALF CMP AL,0 ; AL<> 0 IF ONLY 1ST HALF SCANNED JE S18 ; IF = 0, THEN ALL HAS BEEN SCANNED SUB AX,AX MOV DS,AX ; ESTABLISH ADDRESSING TO VECTOR ASSUME DS:ABS0 LES DI,EXT_PTR ; GET POINTER MOV AX,ES ; SEE IF THE POINTER REALLY EXISTS OR AX,DI ; IF ALL 0, THEN DOESN'T EXIST JZ S18 ; NO SENSE LOOKING MOV AL,128 ; ORIGIN FOR SECOND HALF JMP S16 ; GO BACK AND TRY FOR IT ASSUME DS:DATA ;------ CHARACTER IS FOUND ( AL=0 IF NOT FOUND ) S18: ADD SP,8 ; READJUST THE STACK, THROW AWAY SAVE JMP VIDEO_RETURN ; ALL DONE GRAPHICS_READ ENDP ;-------------------------------------------- ; EXPAND_MED_COLOR ; THIS ROUTINE EXPANDS THE LOW 2 BITS IN BL TO ; FILL THE ENTIRE BX REGISTER ; ENTRY -- ; BL = COLOR TO BE USED ( LOW 2 BITS ) ; EXIT -- ; BX = COLOR TO BE USED ( 8 REPLICATIONS OF THE 2 COLOR BITS ) ;-------------------------------------------- S19 PROC NEAR AND BL,3 ; ISOLATE THE COLOR BITS MOV AL,BL ; COPY TO AL PUSH CX ; SAVE REGISTER MOV CX,3 ; NUMBER OF TIMES TO DO THIS S20: SAL AL,1 SAL AL,1 ; LEFT SHIFT BY 2 OR BL,AL ; ANOTHER COLOR VERSION INTO BL LOOP S20 ; FILL ALL OF BL MOV BH,BL ; FILL UPPER PORTION POP CX ; REGISTER BACK RET ; ALL DONE S19 ENDP ;-------------------------------------------- ; EXPAND_BYTE ; THIS ROUTINE TAKES THE BYTE IN AL AND DOUBLES ALL ; OF THE BITS, TURNING THE 8 BITS INTO 16 BITS. ; THE RESULT IS LEFT IN AX ;-------------------------------------------- S21 PROC NEAR PUSH DX ; SAVE REGISTERS PUSH CX PUSH BX MOV DX,0 ; RESULT REGISTER MOV CX,1 ; MASK REGISTER S22: MOV BX,AX ; BASE INTO TEMP AND BX,CX ; USE MASK TO EXTRACT A BIT OR DX,BX ; PUT INTO RESULT REGISTER SHL AX,1 SHL CX,1 ; SHIFT BASE AND MASK BY 1 MOV BX,AX ; BASE TO TEMP AND BX,CX ; EXTRACT THE SAME BIT OR DX,BX ; PUT INTO RESULT SHL CX,1 ; SHIFT ONLY MASK NOW, MOVING TO NEXT BASE JNC S22 ; USE MASK BIT COMING OUT TO TERMINATE MOV AX,DX ; RESULT TO PARM REGISTER POP BX POP CX ; RECOVER REGISTERS POP DX RET ; ALL DONE S21 ENDP ;-------------------------------------------- ; MED_READ_BYTE ; THIS ROUTINE WILL TAKE 2 BYTES FROM THE REGEN BUFFER, ; COMPARE AGAINST THE CURRENT FOREGROUND COLOR, AND PLACE ; THE CORRESPONDING ON/OFF BIT PATTERN INTO THE CURRENT ; POSITION IN THE SAVE AREA ; ENTRY -- ; SI,DS = POINTER TO REGEN AREA OF INTEREST ; BX = EXPANDED FOREGROUND COLOR ; BP = POINTER TO SAVE AREA ; EXIT -- ; BP IS INCREMENT AFTER SAVE ;--------------------------------------------- S23 PROC NEAR MOV AH,[SI] ; GET FIRST BYTE MOV AL,[SI+1] ; GET SECOND BYTE MOV CX,0C000H ; 2 BIT MASK TO TEST THE ENTRIES MOV DL,0 ; RESULT REGISTER S24: TEST AX,CX ; IS THIS SECTION BACKGROUND? CLC ; CLEAR CARRY IN HOPES THAT IT IS JZ S25 ; IF ZERO, IT IS BACKGROUND STC ; WASN'T, SO SET CARRY S25: RCL DL,1 ; MOVE THAT BIT INTO THE RESULT SHR CX,1 SHR CX,1 ; MOVE THE MASK TO THE RIGHT BY 2 BITS JNC S24 ; DO IT AGAIN IF MASK DIDN'T FALL OUT MOV [BP],DL ; STORE RESULT IN SAVE AREA INC BP ; ADJUST POINTER RET ; ALL DONE S23 ENDP ;----------------------------------------- ; V4_POSITION ; THIS ROUTINE TAKES THE CURSOR POSITION CONTAINED IN ; THE MEMORY LOCATION, AND CONVERTS IT INTO AN OFFSET ; INTO THE REGEN BUFFER, ASSUMING ONE BYTE/CHAR. ; FOR MEDIUM RESOLUTION GRAPHICS, THE NUMBER MUST ; BE DOUBLED. ; ENTRY -- NO REGISTERS,MEMORY LOCATION CURSOR_POSN IS USED ; EXIT-- ; AX CONTAINS OFFSET INTO REGEN BUFFER ;----------------------------------------- S26 PROC NEAR MOV AX,CURSOR_POSN ; GET CURRENT CURSOR GRAPH_POSN LABEL NEAR PUSH BX ; SAVE REGISTER MOV BX,AX ; SAVE A COPY OF CURRENT CURSOR MOV AL,AH ; GET ROWS TO AL MUL BYTE PTR CRT_COLS ; MULTIPLY BY BYTES/COLUMN SHL AX,1 ; MULTIPLY * 4 SINCE 4 ROWS/BYTE SHL AX,1 SUB BH,BH ; ISOLATE COLUMN VALUE ADD AX,BX ; DETERMINE OFFSET POP BX ; RECOVER POINTER RET ; ALL DONE S26 ENDP ;-------------------------------------------- ; WRITE_TTY ; THIS INTERFACE PROVIDES A TELETYPE LIKE INTERFACE TO THE ; VIDEO CARD. THE INPUT CHARACTER IS WRITTEN TO THE CURRENT ; CURSOR POSITION, AND THE CURSOR IS MOVED TO THE NEXT POSITION. ; IF THE CURSOR LEAVES THE LAST COLUMN OF THE FIELD, THE COLUMN ; IS SET TO ZERO, AND THE ROW VALUE IS INCREMENTED. IF THE ROW ; ROW VALUE LEAVES THE FIELD, THE CURSOR IS PLACED ON THE LAST ROW, ; FIRST COLUMN, AND THE ENTIRE SCREEN IS SCROLLED UP ONE LINE. ; WHEN THE SCREEN IS SCROLLED UP, THE ATTRIBUTE FOR FILLING THE ; NEWLY BLANKED LINE IS READ FROM THE CURSOR POSITION ON THE PREVIOUS ; LINE BEFORE THE SCROLL, IN CHARACTER MODE. IN GRAPHICS MODE, ; THE 0 COLOR IS USED. ; ENTRY -- ; (AH) = CURRENT CRT MODE ; (AL) = CHARACTER TO BE WRITTEN ; NOTE THAT BACK SPACE, CAR RET, BELL AND LINE FEED ARE HANDLED ; AS COMMANDS RATHER THAN AS DISPLAYABLE GRAPHICS ; (BL) = FOREGROUND COLOR FOR CHAR WRITE IF CURRENTLY IN A GRAPHICS MODE ; EXIT -- ; ALL REGISTERS SAVED ;--------------------------------------------- ASSUME CS:CODE,DS:DATA WRITE_TTY PROC NEAR PUSH AX ; SAVE REGISTERS PUSH AX ; SAVE CHAR TO WRITE MOV AH,3 INT 10H ; READ THE CURRENT CURSOR POSITION POP AX ; RECOVER CHAR ;------ DX NOW HAS THE CURRENT CURSOR POSITION CMP AL,8 ; IS IT A BACKSPACE JE U8 ; BACK_SPACE CMP AL,0DH ; IS IT CARRIAGE RETURN JE U9 ; CAR_RET CMP AL,0AH ; IS IT A LINE FEED JE U10 ; LINE_FEED CMP AL,07H ; IS IT A BELL JE U11 ; BELL ;------ WRITE THE CHAR TO THE SCREEN MOV BH,ACTIVE_PAGE ; GET THE CURRENT ACTIVE PAGE MOV AH,10 ; WRITE CHAR ONLY MOV CX,1 ; ONLY ONE CHAR INT 10H ; WRITE THE CHAR ;------ POSITION THE CURSOR FOR NEXT CHAR INC DL CMP DL,BYTE PTR CRT_COLS ; TEST FOR COLUMN OVERFLOW JNZ U7 ; SET CURSOR MOV DL,0 ; COLUMN FOR CURSOR CMP DH,24 JNZ U6 ; SET_CURSOR_INC ;------ SCROLL REQUIRED U1: MOV AH,2 MOV BH,0 INT 10H ; SET THE CURSOR ;------ DETERMINE VALUE TO FILL WITH DURING SCROLL MOV AL,CRT_MODE ; GET THE CURRENT MODE CMP AL,4 JC U2 ; READ_CURSOR CMP AL,7 MOV BH,0 ; FILL WITH BACKGROUND JNE U3 ; SCROLL_UP U2: ; READ_CURSOR MOV AH,8 INT 10H ; READ CHAR/ATTR AT CURRENT CURSOR MOV BH,AH ; STORE IN BH U3: ; SCROLL_UP MOV AX,601H ; SCROLL ONE LINE MOV CX,0 ; UPPER LEFT CORNER MOV DH,24 ; LOWER RIGHT ROW MOV DL,BYTE PTR CRT_COLS ; LOWER RIGHT COLUMN DEC DL U4: ; VIDEO_CALL_RETURN INT 10H ; SCROLL UP THE SCREEN U5: ; TTY-RETURN POP AX ; RESTORE THE CHARACTER JMP VIDEO_RETURN ; RETURN TO CALLER U6: ; SET_CURSOR_INC INC DH ; NEXT ROW U7: ; SET_CURSOR MOV AH,2 JMP U4 ; ESTABLISH THE NEW CURSOR ;------ BACK SPACE FOUND U8: CMP DL,0 ; ALREADY AT END OF LINE JE U7 ; SET_CURSOR DEC DL ; NO -- JUST MOVE IT BACK JMP U7 ; SET_CURSOR ;------ CARRIAGE RETURN FOUND U9: MOV DL,0 ; MOVE TO FIRST COLUMN JMP U7 ; SET_CURSOR ;------ LINE FEED FOUND U10: CMP DH,24 ; BOTTOM OF SCREEN JNE U6 ; YES, SCROLL THE SCREEN JMP U1 ; NO, JUST SET THE CURSOR ;------ BELL FOUND U11: MOV BL,2 ; SET UP COUNT FOR BEEP CALL BEEP ; SOUND THE POD BELL JMP U5 ; TTY_RETURN WRITE_TTY ENDP ;------------------------------------------- ; LIGHT PEN ; THIS ROUTINE TESTS THE LIGHT PEN SWITCH AND THE LIGHT ; PEN TRIGGER. IF BOTH ARE SET, THE LOCATION OF THE LIGHT ; PEN IS DETERMINED. OTHERWISE, A RETURN WITH NO INFORMATION ; IS MADE. ; ON EXIT: ; (AH) = 0 IF NO LIGHT PEN INFORMATION IS AVAILABLE ; BX,CX,DX ARE DESTROYED ; (AH) = 1 IF LIGHT PEN IS AVAILABLE ; (DH,DL) = ROW,COLUMN OF CURRENT LIGHT PEN POSITION ; (CH) = RASTER POSITION ; (BX) = BEST GUESS AT PIXEL HORIZONTAL POSITION ;-------------------------------------------- ASSUME CS:CODE,DS:DATA ;------ SUBTRACT_TABLE V1 LABEL BYTE DB 3,3,5,5,3,3,3,4 ; READ_LPEN PROC NEAR ;------ WAIT FOR LIGHT PEN TO BE DEPRESSED MOV AH,0 ; SET NO LIGHT PEN RETURN CODE MOV DX,ADDR_6845 ; GET BASE ADDRESS OF 6845 ADD DX,6 ; POINT TO STATUS REGISTER IN AL,DX ; GET STATUS REGISTER TEST AL,4 ; TEST LIGHT PEN SWITCH JNZ V6 ; NOT SET, RETURN ;------ NOW TEST FOR LIGHT PEN TRIGGER TEST AL,2 ; TEST LIGHT PEN TRIGGER JZ V7 ; RETURN WITHOUT RESETTING TRIGGER ;------ TRIGGER HAS BEEN SET, READ THE VALUE IN MOV AH,16 ; LIGHT PEN REGISTERS IN 6845 ;------ INPUT REGS POINTED TO BY AH, AND CONVERT TO ROW COLUMN IN DX MOV DX,ADDR_6845 ; ADDRESS REGISTER FOR 6845 MOV AL,AH ; REGISTER TO READ OUT DX,AL ; SET IT UP INC DX ; DATA REGISTER IN AL,DX ; GET THE VALUE MOV CH,AL ; SAVE IN CX DEC DX ; ADDRESS REGISTER INC AH MOV AL,AH ; SECOND DATA REGISTER OUT DX,AL INC DX ; POINT TO DATA REGISTER IN AL,DX ; GET SECOND DATA VALUE MOV AH,CH ; AX HAS INPUT VALUE ;------ AX HAS THE VALUE READ IN FROM THE 6845 MOV BL,CRT_MODE SUB BH,BH ; MODE VALUE TO BX MOV BL,CS:V1[BX] ; DETERMINE AMOUNT TO SUBTRACT SUB AX,BX ; TAKE IT AWAY SUB AX,CRT_START ; CONVERT TO CORRECT PAGE ORIGIN JNS V2 ; IF POSITIVE, DETERMINE MODE MOV AX,0 ; <0 PLAYS AS 0 ;------ DETERMINE MODE OF OPERATION V2: ; DETERMINE_MODE MOV CL,3 ; SET *8 SHIFT COUNT CMP CRT_MODE,4 ; DETERMINE IF GRAPHICS OR ALPHA JB V4 ; ALPHA_PEN CMP CRT_MODE,7 JE V4 ; ALPHA_PEN ;------ GRAPHICS MODE MOV DL,40 ; DIVISOR FOR GRAPHICS DIV DL ; DETERMINE ROW(AL) AND COLUMN(AH) ; AL RANGE 0-99, AH RANGE 0-39 ;------ DETERMINE GRAPHIC ROW POSITION MOV CH,AL ; SAVE ROW VALUE IN CH ADD CH,CH ; *2 FOR EVEN/ODD FIELD MOV BL,AH ; COLUMN VALUE TO BX SUB BH,BH ; MULTIPLY BY 8 FOR MEDIUM RES CMP CRT_MODE,6 ; DETERMINE MEDIUM OR HIGH RES JNE V3 ; NOT_HIGH_RES MOV CL,4 ; SHIFT VALUE FOR HIGH RES SAL AH,1 ; COLUMN VALUE TIMES 2 FOR HIGH RES V3: ; NOT_HIGH_RES SHL BX,CL ; MULTIPLY *16 FOR HIGH RES ;------ DETERMINE ALPHA CHAR POSITION MOV DL,AH ; COLUMN VALUE FOR RETURN MOV DH,AL ; ROW VALUE SHR DH,1 ; DIVIDE BY 4 SHR DH,1 ; FOR VALUE IN 0-24 RANGE JMP SHORT V5 ; LIGHT_PEN_RETURN_SET ;------ ALPHA MODE ON LIGHT PEN V4: ; ALPHA_PEN DIV BYTE PTR CRT_COLS ; DETERMINE ROW,COLUMN VALUE MOV DH,AL ; ROWS TO DH MOV DL,AH ; COLS TO DL SAL AL,CL ; MULTIPLY ROWS *8 MOV CH,AL ; GET RASTER VALUE TO RETURN REG MOV BL,AH ; COLUMN VALUE XOR BH,BH ; TO BX SAL BX,CL V5: ; LIGHT_PEN_RETURN_SET MOV AH,1 ; INDICATE EVERTHING SET V6: ; LIGHT_PEN_RETURN PUSH DX ; SAVE RETURN VALUE (IN CASE) MOV DX,ADDR_6845 ; GET BASE ADDRESS ADD DX,7 ; POINT TO RESET PARM OUT DX,AL ; ADDRESS, NOT DATA, IS IMPORTANT POP DX ; RECOVER VALUE V7: ; RETURN_NO_RESET POP DI POP SI POP DS ; DISCARD SAVED BX,CX,DX POP DS POP DS POP DS POP ES IRET READ_LPEN ENDP ;--- INT 12 --------------------------------- ; MEMORY_SIZE_DETERMINE ; THIS ROUTINE DETERMINES THE AMOUNT OF MEMORY IN THE SYSTEM ; AS REPRESENTED BY THE SWITCHES ON THE PLANAR. NOTE THAT ; THE SYSTEM MAY NOT BE ABLE TO USE I/O MEMORY UNLESS THERE ; IS A FULL COMPLEMENT OF 64K BYTES ON THE PLANAR. ; INPUT ; NO REGISTERS ; THE MEMORY_SIZE VARIABLE IS SET DURING POWER ON DIAGNOSTICS ; ACCORDING TO THE FOLLOWING HARDWARE ASSUMPTIONS: ; PORT 60 BITS 3,2 = 00 - 16K BASE RAM ; 01 - 32K BASE RAM ; 10 - 48K BASE RAM ; 11 - 64K BASE RAM ; PORT 62 BITS 3-0 INDICATE AMOUNT OF I/O RAM IN 32K INCREMENTS ; E.G., 0000 - NO RAM IN I/O CHANNEL ; 0010 - 64K RAM IN I/O CHANNEL, ETC. ; OUTPUT ; (AX) = NUMBER OF CONTIGUOUS 1K BLOCKS OF MEMORY ;-------------------------------------------- ASSUME CS:CODE,DS:DATA MEMORY_SIZE_DETERMINE PROC FAR STI ; INTERRUPTS BACK ON PUSH DS ; SAVE SEGMENT MOV AX,DATA ; ESTABLISH ADDRESSING MOV DS,AX MOV AX,MEMORY_SIZE ; GET VALUE POP DS ; RECOVER SEGMENT IRET ; RETURN TO CALLER MEMORY_SIZE_DETERMINE ENDP ;--- INT 11 ----------------------------------- ; EQUIPMENT DETERMINATION ; THIS ROUTINE ATTEMPTS TO DETERMINE WHAT OPTIONAL ; DEVICES ARE ATTACHED TO THE SYSTEM. ; INPUT ; NO REGISTERS ; THE EQUIP_FLAG VARIABLE IS SET DURING THE POWER ON DIAGNOSTICS ; USING THE FOLLOWING HARDWARE ASSUMPTIONS: ; PORT 60 = LOW ORDER BYTE OF EQUIPMENT ; PORT 3FA = INTERRUPT ID REGISTER OF 8250 ; BITS 7-3 ARE ALWAYS 0 ; PORT 378 = OUTPUT PORT OF PRINTER -- 8255 PORT THAT ; CAN BE READ AS WELL AS WRITTEN ; OUTPUT ; (AX) IS SET, BIT SIGNIFICANT, TO INDICATE ATTACHED I/O ; BIT 15,14 = NUMBER OF PRINTERS ATTACHED ; BIT 13 NOT USED ; BIT 12 = GAME I/O ATTACHED ; BIT 11,10,9 = NUMBER OF RS232 CARDS ATTACHED ; BIT 8 UNUSED ; BIT 7,6 = NUMBER OF DISKETTE DRIVES ; 00=1, 01=2, 10-3, 11=4 ONLY IF BIT 0 = 1 ; BIT 5,4 = INITIAL VIDEO MODE ; 00 - UNUSED ; 01 - 40X25 BW USING COLOR CARD ; 10 - 80X25 BW USING COLOR CARD ; 11 - 80X25 BW USING BW CARD ; BIT 3,2 = PLANAR RAM SIZE (00=16K,01=32K,10=48K,11=64K) ; BIT 1 NOT USED ; BIT 0 = IPL FROM DISKETTE -- THIS BIT INDICATES THAT THERE ARE DISKETTE ; DRIVES ON THE SYSTEM ; ; NO OTHER REGISTERS AFFECTED ;--------------------------------------------- ASSUME CS:CODE,DS:DATA EQUIPMENT PROC FAR STI ; INTERRUPTS BACK ON PUSH DS ; SAVE SEGMENT REGISTER MOV AX,DATA ; ESTABLISH ADDRESSING MOV DS,AX MOV AX,EQUIP_FLAG ; GET THE CURRENT SETTINGS POP DS ; RECOVER SEGMENT IRET ; RETURN TO CALLER EQUIPMENT ENDP ;--- INT 15 -------------------------------- ; CASSETTE I/O ; (AH) = 0 TURN CASSETTE MOTOR ON ; (AH) = 1 TURN CASSETTE MOTOR OFF ; (AH) = 2 READ 1 OR MORE 256 BYTE BLOCKS FROM CASSETTE ; (ES,BX) = POINTER TO DATA BUFFER ; (CX) = COUNT OF BYTES TO READ ; ON EXIT: ; (ES,BX) = POINTER TO LAST BYTE READ + 1 ; (DX) = COUNT OF BYTES ACTUALLY READ ; (CY) = 0 IF NO ERROR OCCURRED ; = 1 IF ERROR OCCURRED ; (AH) = ERROR RETURN IF (CY)= 1 ; = 01 IF CRC ERROR WAS DETECTED ; = 02 IF DATA TRANSITIONS ARE LOST ; = 04 IF NO DATA WAS FOUND ; (AH) = 3 WRITE 1 OR MORE 256 BYTE BLOCKS TO CASSETTE ; (ES,BX) = POINTER TO DATA BUFFER ; (CX) = COUNT OF BYTES TO WRITE ; ON EXIT: ; (EX,BX) = POINTER TO LAST BYTE WRITTEN + 1 ; (CX) = 0 ; (AH) = ANY OTHER THAN ABOVE VALUES CAUSES (CY)= 1 ; AND (AH)= 80 TO BE RETURNED (INVALID COMMAND). ;-------------------------------------------- ASSUME DS:DATA,ES:NOTHING,SS:NOTHING,CS:CODE CASSETTE_IO PROC FAR STI ; INTERRUPTS BACK ON PUSH DS ; ESTABLISH ADDRESSING TO DATA PUSH AX MOV AX,DATA MOV DS,AX AND BIOS_BREAK, 7FH ; MAKE SURE BREAK FLAG IS OFF POP AX CALL W1 ; CASSETTE_IO_CONT POP DS RET 2 ; INTERRUPT RETURN CASSETTE_IO ENDP W1 PROC NEAR ;-------------------------------------------- ; PURPOSE: ; TO CALL APPROPRIATE ROUTINE DEPENDING ON REG AH ; ; AH ROUTINE ;-------------------------------------------- ; 0 MOTOR ON ; 1 MOTOR OFF ; 2 READ CASSETTE BLOCK ; 3 WRITE CASSETTE BLOCK ;-------------------------------------------- OR AH,AH ;TURN ON MOTOR? JZ MOTOR_ON ;YES, DO IT DEC AH ;TURN OFF MOTOR? JZ MOTOR_OFF ;YES, DO IT DEC AH ;READ CASSETTE BLOCK? JZ READ_BLOCK ;YES, DO IT DEC AH ;WRITE CASSETTE BLOCK? JNZ W2 ; NOT_DEFINED JMP WRITE_BLOCK ;YES, DO IT W2: ;COMMAND NOT DEFINED MOV AH,080H ;ERROR, UNDEFINED OPERATION STC ;ERROR FLAG RET W1 ENDP MOTOR_ON PROC NEAR ;-------------------------------- ; PURPOSE: ; TO TURN ON CASSETTE MOTOR ;--------------------------------- IN AL,PORT_B ;READ CASSETTE OUTPUT AND AL,NOT 08H ; CLEAR BIT TO TURN ON MOTOR W3: OUT PORT_B,AL ;WRITE IT OUT SUB AH,AH ;CLEAR AH RET MOTOR_ON ENDP MOTOR_OFF PROC NEAR ;---------------------------------- ; PURPOSE: ; TO TURN CASSETTE MOTOR OFF ;----------------------------------- IN AL,PORT_B ;READ CASSETTE OUTPUT OR AL,08H ; SET BIT TO TURN OFF JMP W3 ;WRITE IT, CLEAR ERROR, RETURN MOTOR_OFF ENDP READ_BLOCK PROC NEAR ;-------------------------------------------- ; PURPOSE: ; TO READ 1 OR MORE 256 BYTE BLOCKS FROM CASSETTE ; ; ON ENTRY: ; ES IS SEGMENT FOR MEMORY BUFFER (FOR COMPACT CODE) ; BX POINTS TO START OF MEMORY BUFFER ; CX CONTAINS NUMBER OF BYTES TO READ ; ON EXIT: ; BX POINTS 1 BYTE PAST LAST BYTE PUT IN MEM ; CX CONTAINS DECREMENTED BYTE COUNT ; DX CONTAINS NUMBER OF BYTES ACTUALLY READ ; ; CARRY FLAG IS CLEAR IF NO ERROR DETECTED ; CARRY FLAG IS SET IF CRC ERROR DETECTED ;-------------------------------------------- PUSH BX ;SAVE BX PUSH CX ;SAVE CX PUSH SI ; SAVE SI MOV SI, 7 ; SET UP RETRY COUNT FOR LEADER CALL BEGIN_OP ; BEGIN BY STARTING MOTOR W4: ; SEARCH FOR LEADER IN AL,PORT_C ;GET INTIAL VALUE AND AL,010H ;MASK OFF EXTRANEOUS BITS MOV LAST_VAL,AL ;SAVE IN LOC LAST_VAL MOV DX,16250 ; # OF TRANSITIONS TO LOOK FOR W5: ; WAIT_FOR_EDGE TEST BIOS_BREAK,80H ; CHECK FOR BREAK KEY JZ W6 ; JUMP IF NO BREAK KEY JMP W17 ; JUMP IF BREAK KEY HIT W6: DEC DX JNZ W7 ; JUMP IF BEGINNING OF LEADER JMP W17 ; JUMP IF NO LEADER FOUND W7: CALL READ_HALF_BIT ;IGNORE FIRST EDGE JCXZ W5 ; JUMP IF NO EDGE DETECTED MOV DX,0378H ; CHECK FOR HALF BITS MOV CX,200H ;MUST HAVE AT LEAST THIS MANY ONE SIZE ;PULSES BEFORE CHECKNG FOR SYNC BIT (0) IN AL, 021H ; INTERRUPT MASK REGISTER OR AL, 1 ; DISABLE TIMER INTERRUPTS OUT 021H, AL W8: ; SEARCH_LDR TEST BIOS_BREAK, 80H ; CHECK FOR BREAK KEY JNZ W17 ; JUMP IF BREAK KEY HIT PUSH CX ;SAVE REG CX CALL READ_HALF_BIT ;GET PULSE WIDTH OR CX,CX ; CHECK FOR TRANSITION POP CX ;RESTORE ONE BIT COUNTER JZ W4 ; JUMP IF NO TRANSITION CMP DX,BX ;CHECK PULSE WIDTH JCXZ W9 ;IF CX=0 THEN WE CAN LOOK ;FOR SYNC BIT (0) JNC W4 ; JUMP IF ZERO BIT (NOT GOOD LEADER) LOOP W8 ;DEC CX AND READ ANOTHER HALF ONE BIT W9: ; FIND_SYNC JC W8 ; JUMP IF ONE BIT (STILL LEADER) ; A SYNCH BIT HAS BEEN FOUND. READ SYN CHARACTER: CALL READ_HALF_BIT ;SKIP OTHER HALF OF SYNC BIT (0) CALL READ_BYTE ; READ SYN BYTE CMP AL, 16H ; SYNCHRONIZATION CHARACTER JNE W16 ; JUMP IF BAD LEADER FOUND. ;------ GOOD CRC SO READ DATA BLOCK(S) POP SI ; RESTORE REGS POP CX POP BX ;-------------------------------------------- ; READ 1 OR MORE 256 BYTE BLOCKS FROM CASSETTE ; ; ON ENTRY: ; ES IS SEGMENT FOR MEMORY BUFFER (FOR COMPACT CODE) ; BX POINTS TO START OF MEMORY BUFFER ; CX CONTAINS NUMBER OF BYTES TO READ ; ON EXIT: ; BX POINTS 1 BYTE PAST LAST BYTE PUT IN MEM ; CX CONTAINS DECREMENTED BYTE COUNT ; DX CONTAINS NUMBER OF BYTES ACTUALLY READ ;-------------------------------------------- PUSH CX ;SAVE BYTE COUNT W10: ;COME HERE BEFORE EACH ;256 BYTE BLOCK IS READ MOV CRC_REG,0FFFFH ;INIT CRC REG MOV DX,256 ;SET CX TO DATA BLOCK SIZE W11: ; RD_BLK TEST BIOS_BREAK, 80H ; CHECK FOR BREAK KEY JNZ W13 ; JUMP IF BREAK KEY HIT CALL READ_BYTE ;READ BYTE FROM CASSETTE JC W13 ;CY SET INDICATES NO DATA TRANSITIONS JCXZ W12 ;IF WE'VE ALREADY REACHED ;END OF MEMORY BUFFER ;SKIP REST OF BLOCK MOV ES:[BX],AL ;STORE DATA BYTE AT BYTE PTR INC BX ;INC BUFFER PTR DEC CX ;DEC BYTE COUNTER W12: ; LOOP UNTIL DATA BLOCK HAS BEEN READ FROM CASSETTE. DEC DX ;DEC BLOCK CNT JG W11 ; RD_BLK CALL READ_BYTE ;NOW READ TWO CRC BYTES CALL READ_BYTE SUB AH,AH ;CLEAR AN CMP CRC_REG,1D0FH ;IS THE CRC CORRECT JNE W14 ;IF NOT EQUAL CRC IS BAD JCXZ W15 ;IF BYTE COUNT IS ZERO ;THEN WE HAVE READ ENOUGH ;SO WE WILL EXIT JMP W10 ;STILL MORE, SO READ ANOTHER BLOCK W13: ;MISSING_DATA ;NO DATA TRANSITIONS SO MOV AH,01H ;SET AH=02 TO INDICATE ;DATA TIMEOUT W14: ; BAD_CRC INC AH ;EXIT EARLY ON ERROR ;SET AH=01 TO INDICATE CRC ERROR W15: ; RD_BLK_EX POP DX ;CALCULATE COUNT OF SUB DX,CX ;DATA BYTES ACTUALLY READ ;RETURN COUNT IN REG DX PUSH AX ;SAVE AX (RET CODE) TEST AH, 03H ; CHECK FOR ERRORS JNZ W18 ; JUMP IF ERROR DETECTED CALL READ_BYTE ;READ TRAILER JMP SHORT W18 ;SKIP TO TURN OFF MOTOR W16: ; BAD_LEADER DEC SI ; CHECK RETRIES JZ W17 ; JUMP IF TOO MANY RETRIES JMP W4 ; JUMP IF NOT TOO MANY RETRIES W17: ;NO VALID DATA FOUND ;------ NO DATA FROM CASSETTE ERROR, I.E. TIMEOUT POP SI ; RESTORE REGS POP CX ;RESTORE REGS POP BX SUB DX,DX ;ZERO NUMBER OF BYTES READ MOV AH,04H ;TIME OUT ERROR (NO LEADER) PUSH AX W18: ; MOT-OFF IN AL, 021H ; RE_ENABLE INTERRUPTS AND AL, 0FFH-1 OUT 021H, AL CALL MOTOR_OFF ;TURN OFF MOTOR POP AX ;RESTORE RETURN CODE CMP AH,01H ;SET CARRY IF ERROR (AH>0) CMC RET ;FINISHED READ_BLOCK ENDP ;------------------------------------------ READ_BYTE PROC NEAR ; PURPOSE: ; TO READ A BYTE FROM CASSETTE ; ; ON EXIT REG AL CONTAINS READ DATA BYTE ;------------------------------------------- PUSH BX ;SAVE REGS BX,CX PUSH CX MOV CL,8H ; SET BIT COUNTER FOR 8 BITS W19: ; BYTE_ASM PUSH CX ; SAVE CX ;------------------------------------------- ; READ DATA BIT FROM CASSETTE ;------------------------------------------- CALL READ_HALF_BIT ;READ ONE PULSE JCXZ W21 ;IF CX=0 THEN TIMEOUT ;BECAUSE OF NO DATA TRANSITIONS PUSH BX ;SAVE 1ST HALF BIT'S ;PULSE WIDTH (IN BX) CALL READ_HALF_BIT ;READ COMPLEMENTARY PULSE POP AX ;COMPUTE DATA BIT JCXZ W21 ;IF CX=0 THEN TIMEOUT DUE TO ;NO DATA TRANSITIONS ADD BX,AX ;PERIOD CMP BX, 06F0H ; CHECK FOR ZERO BIT CMC ; CARRY IS SET IF ONE BIT LAHF ;SAVE CARRY IN AH POP CX ;RESTORE CX ;NOTE: ; MS BIT OF BYTE IS READ FIRST. ; REG CH IS SHIFTED LEFT WITH ; CARRY BEING INSERTED INTO LS ; BIT OF CH. ; AFTER ALL 8 BITS HAVE BEEN ; READ, THE MS BIT OF THE DATA BYTE ; WILL BE IN THE MS BIT OF REG CH RCL CH,1 ;ROTATE REG CH LEFT WITH CARRY TO ; LS BIT OF REG CH SAHF ;RESTORE CARRY FOR CRC ROUTINE CALL CRC_GEN ;GENERATE CRC FOR BIT DEC CL ;LOOP TILL ALL 8 BITS OF DATA ;ASSEMBLED IN REG CH JNZ W19 ; BYTE_ASM MOV AL,CH ;RETURN DATA BYTE IN REG AL CLC W20: ; RD_BYT_EX POP CX ;RESTORE REGS CX,BX POP BX RET ;FINISHED W21: ; NO_DATA POP CX ;RESTORE CX STC ;INDICATE ERROR JMP W20 ; RD_BYT_EX READ_BYTE ENDP ;-------------------------------------------- READ_HALF_BIT PROC NEAR ; PURPOSE ; TO COMPUTE TIME TILL NEXT DATA ; TRANSITION (EDGE) ; ; ON ENTRY: ; EDGE_CNT CONTAINS LAST EDGE COUNT ; ; ON EXIT: ; AX CONTAINS OLD LAST EDGE COUNT ; BX CONTAINS PULSE WIDTH (HALF BIT) ;---------------------------------------- MOV CX, 100 ; SET TIME TO WAIT FOR BIT MOV AH,LAST_VAL ;GET PRESENT INPUT VALUE W22: ; RD-H-BIT IN AL,PORT_C ;INPUT DATA BIT AND AL,010H ;MASK OFF EXTRANEOUS BITS CMP AL,AH ;SAME AS BEFORE? LOOPE W22 ;LOOP TILL IT CHANGES MOV LAST_VAL,AL ;UPDATE LAST_VAL WITH NEW VALUE MOV AL,0 ;READ TIMER'S COUNTER COMMAND OUT TIM_CTL,AL ;LATCH COUNTER IN AL,TIMER0 ;GET LS BYTE MOV AH,AL ;SAVE IN AH IN AL,TIMER0 ;GET MS BYTE XCHG AL,AH ;XCHG AL,AH MOV BX,EDGE_CNT ;BX GETS LAST EDGE COUNT SUB BX,AX ;SET BX EQUAL TO HALF BIT PERIOD MOV EDGE_CNT,AX ;UPDATE EDGE COUNT; RET READ_HALF_BIT ENDP ;----------------------------------------- WRITE_BLOCK PROC NEAR ; ; WRITE 1 OR MORE 256 BYTE BLOCKS TO CASSETTE. ; THE DATA IS PADDED TO FILL OUT THE LAST 256 BYTE BLOCK. ; ; ON ENTRY: ; BX POINTS TO MEMORY BUFFER ADDRESS ; CX CONTAINS NUMBER OF BYTES TO WRITE ; ; ON EXIT: ; BX POINTS 1 BYTE PAST LAST BYTE WRITTEN TO CASSETTE ; CX IS ZERO ;-------------------------------------------- PUSH BX PUSH CX IN AL,PORT_B ;DISABLE SPEAKER AND AL,NOT 02H OR AL, 01H ; ENABLE TIMER OUT PORT_B,AL MOV AL,0B6H ; SET UP TIMER -- MODE 3 SQUARE WAVE OUT TIM_CTL,AL CALL BEGIN_OP ; START MOTOR AND DELAY MOV AX,1184 ; SET NORMAL BIT SIZE CALL W31 ; SET_TIMER MOV CX,0800H ;SET CX FOR LEADER BYTE COUNT W23: ; WRITE LEADER STC ; WRITE ONE BITS CALL WRITE_BIT ; LOOP W23 ; LOOP 'TIL LEADER IS WRITTEN CLC ;WRITE SYNC BIT (0) CALL WRITE_BIT POP CX ;RESTORE REGS CX,BX POP BX MOV AL, 16H ; WRITE SYN CHARACTER CALL WRITE_BYTE ; ;------------------------------------------- ; WRITE 1 OR MORE 256 BYTE BLOCKS TO CASSETTE ; ; ON ENTRY: ; BX POINTS TO MEMORY BUFFER ADDRESS ; CX CONTAINS NUMBER OF BYTES TO WRITE ; ; ON EXIT: ; BX POINTS 1 BYTE PAST LAST BYTE WRITTEN TO CASSETTE ; CX IS ZERO ;------------------------------------------ WR_BLOCK: MOV CRC_REG,0FFFFH ;INIT CRC MOV DX,256 ;FOR 256 BYTES W24: ; WR_BLK MOV AL,ES:[BX] ;READ BYTE FROM MEM CALL WRITE_BYTE ;WRITE IT TO CASSETTE JCXZ W25 ;UNLESS CX=0, ADVANCE PTRS & DEC COUNT INC BX ;INC BUFFER POINTER DEC CX ;DEC BYTE COUNTER W25: ; SKIP_ADV DEC DX ;DEC BLOCK CNT JG W24 ;LOOP TILL 256 BYTE BLOCK ; IS WRITTEN TO TAPE ;------------------- WRITE CRC -------------- ; WRITE 1'S COMPLEMENT OF CRC REG TO CASSETTE ; WHICH IS CHECKED FOR CORRECTNESS WHEN THE BLOCK IS READ ; ; REG AX IS MODIFIED ;------------------------------------------ MOV AX,CRC_REG ;WRITE THE ONE'S COMPLEMENT OF THE ; TWO BYTE CRC TO TAPE NOT AX ;FOR 1'S COMPLEMENT PUSH AX ;SAVE IT XCHG AH,AL ;WRITE MS BYTE FIRST CALL WRITE_BYTE ;WRITE IT POP AX ;GET IT BACK CALL WRITE_BYTE ;NOW WRITE LS BYTE OR CX,CX ;IS BYTE COUNT EXHAUSTED? JNZ WR_BLOCK ;JUMP IF NOT DONE YET PUSH CX ;SAVE REG CX MOV CX, 32 ;WRITE OUT TRAILER BITS W26: ; TRAIL_LOOP STC CALL WRITE_BIT LOOP W26 ; WRITE UNTIL TRAILER WRITTEN POP CX ;RESTORE REG CX MOV AL, 0B0H ; TURN TIMER2 OFF OUT TIM_CTL,AL MOV AX, 1 CALL W31 ; SET_TIMER CALL MOTOR_OFF ;TURN MOTOR OFF SUB AX,AX ;NO ERRORS REPORTED ON WRITE OP RET ;FINISHED WRITE_BLOCK ENDP ;------------------------------------------ WRITE_BYTE PROC NEAR ; WRITE A BYTE TO CASSETTE. ; BYTE TO WRITE IS IN REG AL. ;-------------------------------------------- PUSH CX ;SAVE REGS CX,AX PUSH AX MOV CH,AL ;AL=BYTE TO WRITE. ; (MS BIT WRITTEN FIRST) MOV CL,8 ;FOR 8 DATA BITS IN BYTE. ; NOTE: TWO EDGES PER BIT W27: ; DISASSEMBLE THE DATA BIT RCL CH,1 ;ROTATE MS BIT INTO CARRY PUSHF ;SAVE FLAGS. ; NOTE: DATA BIT IS IN CARRY CALL WRITE_BIT ;WRITE DATA BIT POPF ;RESTORE CARRY FOR CRC CALC CALL CRC_GEN ;COMPUTE CRC ON DATA BIT DEC CL ;LOOP TILL ALL 8 BITS DONE JNZ W27 ; JUMP IF NOT DONE YET POP AX ;RESTORE REGS AX,CX POP CX RET ;WE ARE FINISHED WRITE_BYTE ENDP ;--------------------------------------- WRITE_BIT PROC NEAR ; PURPOSE: ; ; TO WRITE A DATA BIT TO CASSETTE ; CARRY FLAG CONTAINS DATA BIT ; I.E. IF SET DATA BIT IS A ONE ; IF CLEAR DATA BIT IS A ZERO ; ; NOTE: TWO EDGES ARE WRITTEN PER BIT ; ONE BIT HAS 500 USEC BETWEEN EDGES ; FOR A 1000 USEC PERIOD (1 MILLISEC) ; ; ZERO BIT HAS 250 USEC BETWEEN EDGES ; FOR A 500 USEC PERIOD (.5 MILLISEC) ; CARRY FLAG IS DATA BIT ;------------------------------------------- ;ASSUME IT'S A '1' MOV AX,1184 ; SET AX TO NOMINAL ONE SIZE JC W28 ; JUMP IF ONE BIT MOV AX,592 ; NO, SET TO NOMINAL ZERO SIZE W28: ; WRITE_BIT_AX PUSH AX ;WRITE BIT WITH PERIOD EQ TO VALUE AX W29: IN AL,PORT_C ;INPUT TIMER_0 OUTPUT AND AL,020H JZ W29 ;LOOP TILL HIGH W30: IN AL,PORT_C ;NOW WAIT TILL TIMER'S OUTPUT IS LOW AND AL,020H JNZ W30 ;RELOAD TIMER WITH PERIOD ;FOR NEXT DATA BIT POP AX ;RESTORE PERIOD COUNT W31: ; SET TIMER OUT 042H, AL ; SET LOW BYTE OF TIMER 2 MOV AL, AH OUT 042H, AL ; SET HIGH BYTE OF TIMER 2 RET WRITE_BIT ENDP ;----------------------------------------- CRC_GEN PROC NEAR ; UPDATE CRC REGISTER WITH NEXT DATA BIT ; ; CRC IS USED TO DETECT READ ERRORS ; ; ASSUMES DATA BIT IS IN CARRY ; ; REG AX IS MODIFIED ; FLAGS ARE MODIFIED ;----------------------------------------- MOV AX,CRC_REG ;THE FOLLOWING INSTUCTIONS ;WILL SET THE OVERFLOW FLAG ;IF CARRY AND MS BIT OF CRC ;ARE UNEQUAL RCR AX,1 RCL AX,1 CLC ;CLEAR CARRY JNO W32 ;SKIP IF NO OVERFLOW ;IF DATA BIT XORED WITH ; CRC REG BIT 15 IS ONE XOR AX,0810H ;THEN XOR CRC REG WITH ; 0810H STC ;SET CARRY W32: RCL AX,1 ;ROTATE CARRY (DATA BIT) ; INTO CRC REG MOV CRC_REG,AX ;UPDATE CRC_REG RET ;FINISHED CRC_GEN ENDP ;-------------------------------------------- BEGIN_OP PROC NEAR ; START TAPE AND DELAY ; ;-------------------------------------------- CALL MOTOR_ON ;TURN ON MOTOR MOV BL,42H ;DELAY FOR TAPE DRIVE ;TO GET UP TO SPEED (1/2 SEC) W33: MOV CX,700H ;INNER LOOP= APPROX. 10 MILLISEC W34: LOOP W34 DEC BL JNZ W33 RET BEGIN_OP ENDP ;---------------------------------------- ; CHARACTER GENERATOR GRAPHICS FOR 320X200 AND 640X200 GRAPHICS ;---------------------------------------- CRT_CHAR_GEN LABEL BYTE DB 000H,000H,000H,000H,000H,000H,000H,000H ; D_00 DB 07EH,081H,0A5H,081H,0BDH,099H,081H,07EH ; D_01 DB 07EH,0FFH,0DBH,0FFH,0C3H,0E7H,0FFH,07EH ; D_02 DB 06CH,0FEH,0FEH,0FEH,07CH,038H,010H,000H ; D_03 DB 010H,038H,07CH,0FEH,07CH,038H,010H,008H ; D_04 DB 038H,07CH,038H,0FEH,0FEH,07CH,038H,07CH ; D_05 DB 010H,010H,038H,07CH,0FEH,07CH,038H,07CH ; D_06 DB 000H,000H,018H,03CH,03CH,018H,000H,000H ; D_07 DB 0FFH,0FFH,0E7H,0C3H,0C3H,0E7H,0FFH,0FFH ; D_08 DB 000H,03CH,066H,042H,042H,066H,03CH,000H ; D_09 DB 0FFH,0C3H,099H,0BDH,0BDH,099H,0C3H,0FFH ; D_0A DB 00FH,007H,00FH,07DH,0CCH,0CCH,0CCH,078H ; D_08 DB 03CH,066H,066H,066H,03CH,018H,07EH,018H ; D_0C DB 03FH,033H,03FH,030H,030H,070H,0F0H,0E0H ; D_0D DB 07FH,063H,07FH,063H,063H,067H,0E6H,0C0H ; D_0E DB 099H,05AH,03CH,0E7H,0E7H,03CH,05AH,099H ; D_0F DB 080H,0E0H,0F8H,0FEH,0F8H,0E0H,080H,000H ; D_10 DB 002H,00EH,03EH,0FEH,03EH,00EH,002H,000H ; D_11 DB 018H,03CH,07EH,018H,018H,07EH,03CH,018H ; D_12 DB 066H,066H,066H,066H,066H,000H,066H,000H ; D_13 DB 07FH,0DBH,0DBH,07BH,01BH,01BH,01BH,000H ; D_14 DB 03EH,063H,038H,06CH,06CH,038H,0CCH,078H ; D_15 DB 000H,000H,000H,000H,07EH,07EH,07EH,000H ; D_16 DB 018H,03CH,07EH,018H,07EH,03CH,018H,0FFH ; D_17 DB 018H,03CH,07EH,018H,018H,018H,018H,000H ; D_18 DB 018H,018H,018H,018H,07EH,03CH,018H,000H ; D_19 DB 000H,018H,00CH,0FEH,00CH,018H,000H,000H ; D_1A DB 000H,030H,060H,0FEH,060H,030H,000H,000H ; D_1B DB 000H,000H,0C0H,0C0H,0C0H,0FEH,000H,000H ; D_1C DB 000H,024H,066H,0FFH,066H,024H,000H,000H ; D_1D DB 000H,018H,03CH,07EH,0FFH,0FFH,000H,000H ; D_1E DB 000H,0FFH,0FFH,07EH,03CH,018H,000H,000H ; D_1F DB 000H,000H,000H,000H,000H,000H,000H,000H ; SP D_20 DB 030H,078H,078H,030H,030H,000H,030H,000H ; ! D_21 DB 06CH,06CH,06CH,000H,000H,000H,000H,000H ; " D_22 DB 06CH,06CH,0FEH,06CH,0FEH,06CH,06CH,000H ; # D_23 DB 030H,07CH,0C0H,078H,00CH,0F8H,030H,000H ; $ D_24 DB 000H,0C6H,0CCH,018H,030H,066H,0C6H,000H ; PER CENT D_25 DB 038H,06CH,038H,076H,0DCH,0CCH,076H,000H ; & D_26 DB 060H,060H,0C0H,000H,000H,000H,000H,000H ; ' D_27 DB 018H,030H,060H,060H,060H,030H,018H,000H ; ( D_28 DB 060H,030H,018H,018H,018H,030H,060H,000H ; ) D_29 DB 000H,066H,03CH,0FFH,03CH,066H,000H,000H ; * D_2A DB 000H,030H,030H,0FCH,030H,030H,000H,000H ; + D_2B DB 000H,000H,000H,000H,000H,030H,030H,060H ; , D_2C DB 000H,000H,000H,0FCH,000H,000H,000H,000H ; - D_2D DB 000H,000H,000H,000H,000H,030H,030H,000H ; . D_2E DB 006H,00CH,018H,030H,060H,0C0H,080H,000H ; / D_2F DB 07CH,0C6H,0CEH,0DEH,0F6H,0E6H,07CH,000H ; 0 D_30 DB 030H,070H,030H,030H,030H,030H,0FCH,000H ; 1 D_31 DB 078H,0CCH,00CH,038H,060H,0CCH,0FCH,000H ; 2 D_32 DB 078H,0CCH,00CH,038H,00CH,0CCH,078H,000H ; 3 D_33 DB 01CH,03CH,06CH,0CCH,0FEH,00CH,01EH,000H ; 4 D_34 DB 0FCH,0C0H,0F8H,00CH,00CH,0CCH,078H,000H ; 5 D_35 DB 038H,060H,0C0H,0F8H,0CCH,0CCH,078H,000H ; 6 D_36 DB 0FCH,0CCH,00CH,018H,030H,030H,030H,000H ; 7 D_37 DB 078H,0CCH,0CCH,078H,0CCH,0CCH,078H,000H ; 8 D_38 DB 078H,0CCH,0CCH,07CH,00CH,018H,070H,000H ; 9 D_39 DB 000H,030H,030H,000H,000H,030H,030H,000H ; : D_3A DB 000H,030H,030H,000H,000H,030H,030H,060H ; ; D_3B DB 018H,030H,060H,0C0H,060H,030H,018H,000H ; < D_3C DB 000H,000H,0FCH,000H,000H,0FCH,000H,000H ; = D_3D DB 060H,030H,018H,00CH,018H,030H,060H,000H ; > D_3E DB 078H,0CCH,00CH,018H,030H,000H,030H,000H ; ? D_3F DB 07CH,0C6H,0DEH,0DEH,0DEH,0C0H,078H,000H ; @ D_40 DB 030H,078H,0CCH,0CCH,0FCH,0CCH,0CCH,000H ; A D_41 DB 0FCH,066H,066H,07CH,066H,066H,0FCH,000H ; B D_42 DB 03CH,066H,0C0H,0C0H,0C0H,066H,03CH,000H ; C D_43 DB 0F8H,06CH,066H,066H,066H,06CH,0F8H,000H ; D D_44 DB 0FEH,062H,068H,078H,068H,062H,0FEH,000H ; E D_45 DB 0FEH,062H,068H,078H,068H,060H,0F0H,000H ; F D_46 DB 03CH,066H,0C0H,0C0H,0CEH,066H,03EH,000H ; G D_47 DB 0CCH,0CCH,0CCH,0FCH,0CCH,0CCH,0CCH,000H ; H D_48 DB 078H,030H,030H,030H,030H,030H,078H,000H ; I D_49 DB 01EH,00CH,00CH,00CH,0CCH,0CCH,078H,000H ; J D_4A DB 0E6H,066H,06CH,078H,06CH,066H,0E6H,000H ; K D_4B DB 0F0H,060H,060H,060H,062H,066H,0FEH,000H ; L D_4C DB 0C6H,0EEH,0FEH,0FEH,0D6H,0C6H,0C6H,000H ; M D_4C DB 0C6H,0E6H,0F6H,0DEH,0CEH,0C6H,0C6H,000H ; N D_4E DB 038H,06CH,0C6H,0C6H,0C6H,06CH,038H,000H ; O D_4F DB 0FCH,066H,066H,07CH,060H,060H,0F0H,000H ; P D_50 DB 078H,0CCH,0CCH,0CCH,0DCH,078H,01CH,000H ; Q D_51 DB 0FCH,066H,066H,07CH,06CH,066H,0E6H,000H ; R D_52 DB 078H,0CCH,0E0H,070H,01CH,0CCH,078H,000H ; S D_53 DB 0FCH,0B4H,030H,030H,030H,030H,078H,000H ; T D_54 DB 0CCH,0CCH,0CCH,0CCH,0CCH,0CCH,0FCH,000H ; U D_55 DB 0CCH,0CCH,0CCH,0CCH,0CCH,078H,030H,000H ; V D_56 DB 0C6H,0C6H,0C6H,0D6H,0FEH,0EEH,0C6H,000H ; W D_57 DB 0C6H,0C6H,06CH,038H,038H,06CH,0C6H,000H ; X D_58 DB 0CCH,0CCH,0CCH,078H,030H,030H,078H,000H ; Y D_59 DB 0FEH,0C6H,08CH,018H,032H,066H,0FEH,000H ; Z D_5A DB 078H,060H,060H,060H,060H,060H,078H,000H ; [ D_5B DB 0C0H,060H,030H,018H,00CH,006H,002H,000H ; BACKSLASH D_5C DB 078H,018H,018H,018H,018H,018H,078H,000H ; ] D_5D DB 010H,038H,06CH,0C6H,000H,000H,000H,000H ; CIRCUMFLEX D_5E DB 000H,000H,000H,000H,000H,000H,000H,0FFH ; _ D_5F DB 030H,030H,018H,000H,000H,000H,000H,000H ; D_60 DB 000H,000H,078H,00CH,07CH,0CCH,076H,000H ; LOWER CASE A D_61 DB 0E0H,060H,060H,07CH,066H,066H,0DCH,000H ; L.C. B D_62 DB 000H,000H,078H,0CCH,0C0H,0CCH,078H,000H ; L.C. C D_63 DB 01CH,00CH,00CH,07CH,0CCH,0CCH,076H,000H ; L.C. D D_64 DB 000H,000H,078H,0CCH,0FCH,0C0H,078H,000H ; L.C. E D_65 DB 038H,06CH,060H,0F0H,060H,060H,0F0H,000H ; L.C. F D_66 DB 000H,000H,076H,0CCH,0CCH,07CH,00CH,0F8H ; L.C. G D_67 DB 0E0H,060H,06CH,076H,066H,066H,0E6H,000H ; L.C. H D_68 DB 030H,000H,070H,030H,030H,030H,078H,000H ; L.C. I D_69 DB 00CH,000H,00CH,00CH,00CH,0CCH,0CCH,078H ; L.C. J D_6A DB 0E0H,060H,066H,06CH,078H,06CH,0E6H,000H ; L.C. K D_6B DB 070H,030H,030H,030H,030H,030H,078H,000H ; L.C. L D_6C DB 000H,000H,0CCH,0FEH,0FEH,0D6H,0C6H,000H ; L.C. M D_6D DB 000H,000H,0F8H,0CCH,0CCH,0CCH,0CCH,000H ; L.C. N D_6E DB 000H,000H,078H,0CCH,0CCH,0CCH,078H,000H ; L.C. O D_6F DB 000H,000H,0DCH,066H,066H,07CH,060H,0F0H ; L.C. P D_70 DB 000H,000H,076H,0CCH,0CCH,07CH,00CH,01EH ; L.C. Q D_71 DB 000H,000H,0DCH,076H,066H,060H,0F0H,000H ; L.C. R D_72 DB 000H,000H,07CH,0C0H,078H,00CH,0F8H,000H ; L.C. S D_73 DB 010H,030H,07CH,030H,030H,034H,018H,000H ; L.C. T D_74 DB 000H,000H,0CCH,0CCH,0CCH,0CCH,076H,000H ; L.C. U D_75 DB 000H,000H,0CCH,0CCH,0CCH,078H,030H,000H ; L.C. V D_76 DB 000H,000H,0C6H,0D6H,0FEH,0FEH,06CH,000H ; L.C. W D_77 DB 000H,000H,0C6H,06CH,038H,06CH,0C6H,000H ; L.C. X D_78 DB 000H,000H,0CCH,0CCH,0CCH,07CH,00CH,0F8H ; L.C. Y D_79 DB 000H,000H,0FCH,098H,030H,064H,0FCH,000H ; L.C. Z D_7A DB 01CH,030H,030H,0E0H,030H,030H,01CH,000H ; D_7B DB 018H,018H,018H,000H,018H,018H,018H,000H ; D_7C DB 0E0H,030H,030H,01CH,030H,030H,0E0H,000H ; D_7D DB 076H,0DCH,000H,000H,000H,000H,000H,000H ; D_7E DB 000H,010H,038H,06CH,0C6H,0C6H,0FEH,000H ; DELTA D_7F ;--- INT 1A ------------------------------- ; TIME_OF_DAY ; THIS ROUTINE ALLOWS THE CLOCK TO BE SET/READ ; ; INPUT ; (AH) = 0 READ THE CURRENT CLOCK SETTING ; RETURNS CX = HIGH PORTION OF COUNT ; DX = LOW PORTION OF COUNT ; AL = 0 IF TIMER HAS NOT PASSED 24 HOURS SINCE LAST READ ; <>0 IF ON ANOTHER DAY ; (AH) = 1 SET THE CURRENT CLOCK ; CX = HIGH PORTION OF COUNT ; DX = LOW PORTION OF COUNT ; NOTE: COUNTS OCCUR AT THE RATE OF 1193180/65536 COUNTS/SEC ; (OR ABOUT 18.2 PER SECOND -- SEE EQUATES BELOW) ;-------------------------------------------- ASSUME CS:CODE,DS:DATA TIME_OF_DAY PROC FAR STI ; INTERRUPTS BACK ON PUSH DS ; SAVE SEGMENT PUSH AX ; SAVE PARM MOV AX,DATA MOV DS,AX ; ESTABLISH ADDRESSING TO VALUES POP AX ; GET BACK INPUT PARM OR AH,AH ; AH=0 JZ T2 ; READ_TIME DEC AH ; AH=1 JZ T3 ; SET_TIME T1: ; TOD_RETURN STI ; INTERRUPTS BACK ON POP DS ; RECOVER SEGMENT IRET ; RETURN TO CALLER T2: ; READ_TIME CLI ; NO TIMER INTERRUPTS WHILE READING MOV AL,TIMER_OFL MOV TIMER_OFL,0 ; GET OVERFLOW, AND RESET THE FLAG MOV CX,TIMER_HIGH MOV DX,TIMER_LOW JMP T1 ; TOD_RETURN T3: ; SET_TIME CLI ; NO INTERRUPTS WHILE WRITING MOV TIMER_LOW,DX MOV TIMER_HIGH,CX ; SET THE TIME MOV TIMER_OFL,0 ; RESET OVERFLOW JMP T1 ; TOD_RETURN TIME_OF_DAY ENDP ;-------------------------------------------- ; THIS ROUTINE HANDLES THE TIMER INTERRUPT FROM ; CHANNEL 0 OF THE 8253 TIMER. INPUT FREQUENCY IS 1.19318 MHZ ; AND THE DIVISOR IS 65536, RESULTING IN APPROX. 18.2 INTERRUPTS ; EVERY SECOND. ; ; THE INTERRUPT HANDLER MAINTAINS A COUNT OF INTERRUPTS SINCE POWER ; ON TIME, WHICH MAY BE USED TO ESTABLISH TIME OF DAY. ; THE INTERRUPT HANDLER ALSO DECREMENTS THE MOTOR CONTROL COUNT ; OF THE DISKETTE, AND WHEN IT EXPIRES, WILL TURN OFF THE DISKETTE ; MOTOR, AND RESET THE MOTOR RUNNING FLAGS ; THE INTERRUPT HANDLER WILL ALSO INVOKE A USER ROUTINE THROUGH INTERRUPT ; 1CH AT EVERY TIME TICK. THE USER MUST CODE A ROUTINE AND PLACE THE ; CORRECT ADDRESS IN THE VECTOR TABLE. ;-------------------------------------------- TIMER_INT PROC FAR STI ; INTERRUPTS BACK ON PUSH DS PUSH AX PUSH DX ; SAVE MACHINE STATE MOV AX,DATA MOV DS,AX ; ESTABLISH ADDRESSABILITY INC TIMER_LOW ; INCREMENT TIME JNZ T4 ; TEST_DAY INC TIMER_HIGH ; INCREMENT HIGH WORD OF TIME T4: ; TEST_DAY CMP TIMER_HIGH,018H ; TEST FOR COUNT EQUALLING 24 HOURS JNZ T5 ; DISKETTE_CTL CMP TIMER_LOW,0B0H JNZ T5 ; DISKETTE_CTL ;------ TIMER HAS GONE 24 HOURS MOV TIMER_HIGH,0 MOV TIMER_LOW,0 MOV TIMER_OFL,1 ;------ TEST FOR DISKETTE TIME OUT T5: ; DISKETTE_CTL DEC MOTOR_COUNT JNZ T6 ; RETURN IF COUNT NOT OUT AND MOTOR_STATUS,0F0H ; TURN OFF MOTOR RUNNING BITS MOV AL,0CH MOV DX,03F2H ; FDC_CTL_PORT OUT DX,AL ; TURN OFF THE MOTOR T6: ; TIMER_RET: INT 1CH ; TRANSFER CONTROL TO A USER ROUTINE MOV AL,EOI OUT 020H,AL ; END OF INTERRUPT TO 8259 POP DX POP AX POP DS ; RESET MACHINE STATE IRET ; RETURN FROM INTERRUPT TIMER_INT ENDP ;-------------------------------------------- ; THESE ARE THE VECTORS WHICH ARE MOVED INTO ; THE 8086 INTERRUPT AREA DURING POWER ON ;-------------------------------------------- VECTOR_TABLE LABEL WORD ; VECTOR TABLE FOR MOVE TO INTERRUPTS DW OFFSET TIMER_INT ; INTERRUPT 8 DW CODE DW OFFSET KB_INT ; INTERRUPT 9 DW CODE DD 0 ; INTERRUPT A DD 0 ; INTERRUPT B DD 0 ; INTERRUPT C DD 0 ; INTERRUPT D DW OFFSET DISK_INT ; INTERRUPT E DW CODE DD 0 ; INTERRUPT F DW OFFSET VIDEO_IO ; INTERRUPT 10H DW CODE DW OFFSET EQUIPMENT ; INTERRUPT 11H DW CODE DW OFFSET MEMORY_SIZE_DETERMINE ; INT 12H DW CODE DW OFFSET DISKETTE_IO ; INTERRUPT 13H DW CODE DW OFFSET RS232_IO ; INTERRUPT 14H DW CODE DW OFFSET CASSETTE_IO ; INTERRUPT 15H DW CODE DW OFFSET KEYBOARD_IO ; INTERRUPT 16H DW CODE DW OFFSET PRINTER_IO ; INTERRUPT 17H DW CODE DW 00000H ; INTERRUPT 18H DW 0F600H ; ROM BASIC ENTRY POINT DW OFFSET BOOT_STRAP ; INTERRUPT 19H DW CODE DW TIME_OF_DAY ; INTERRUPT 1AH -- TIME OF DAY DW CODE DW DUMMY_RETURN ; INTERRUPT 1BH -- KEYBOARD BREAK ADDR DW CODE DW DUMMY_RETURN ; INTERRUPT 1CH -- TIMER BREAK ADDR DW CODE DW VIDEO_PARMS ; INTERRUPT 1DH -- VIDEO PARAMETERS DW CODE DW OFFSET DISK_BASE ; INTERRUPT 1EH -- DISK PARMS DW CODE DD 0 ; INTERRUPT 1FH -- POINTER TO VIDEO EXT DUMMY_RETURN: IRET ; DUMMY RETURN FOR BREAK FROM KEYBOARD ;-- INT 5 ---------------------------------- ; THIS LOGIC WILL BE INVOKED BY INTERRUPT 05H TO PRINT ; THE SCREEN. THE CURSOR POSITION AT THE TIME THIS ROUTINE ; IS INVOKED WILL BE SAVED AND RESTORED UPON COMPLETION. THE ; ROUTINE IS INTENDED TO RUN WITH INTERRUPTS ENABLED. ; IF A SUBSEQUENT 'PRINT SCREEN KEY IS DEPRESSED DURING THE ; TIME THIS ROUTINE IS PRINTING IT WILL BE IGNORED. ; ADDRESS 50:0 CONTAINS THE STATUS OF THE PRINT SCREEN: ; ; 50:0 =0 EITHER PRINT SCREEN HAS NOT BEEN CALLED ; OR UPON RETURN FROM A CALL THIS INDICATES ; A SUCCESSFUL OPERATION. ; ; =1 PRINT SCREEN IS IN PROGRESS ; ; =377 ERROR ENCOUNTERED DURING PRINTING ;-------------------------------------------- ASSUME CS:CODE,DS:XXDATA PRINT_SCREEN PROC FAR STI ;MUST RUN WITH INTERRUPTS ENABLED PUSH DS ;MUST USE 50:0 FOR DATA AREA STORAGE PUSH AX PUSH BX PUSH CX ;WILL USE THIS LATER FOR CURSOR LIMITS PUSH DX ;WILL HOLD CURRENT CURSOR POSITION MOV AX,XXDATA ;HEX 50 MOV DS,AX CMP STATUS_BYTE,1 ;SEE IF PRINT ALREADY IN PROGRESS JZ EXIT ; JUMP IF PRINT ALREADY IN PROGRESS MOV STATUS_BYTE,1 ;INDICATE PRINT NOW IN PROGRESS MOV AH,15 ;WILL REQUEST THE CURRENT SCREEN MODE INT 10H ; [AL]=MODE ; [AH]=NUMBER COLUMNS/LINE ; [BH]=VISUAL PAGE ;******************************************** ; AT THIS POINT WE KNOW THE COLUMNS/LINE ARE IN ; [AX] AND THE PAGE IF APPLICABLE IS IN [BH]. THE STACK ; HAS DS,AX,BX,CX,DX PUSHED. [AL] HAS VIDEO MODE ; ;******************************************** MOV CL,AH ;WILL MAKE USE OF [CX] REGISTER TO MOV CH,25 ;CONTROL ROW & COLUMNS CALL CRLF ;CARRIAGE RETURN LINE FEED ROUTINE PUSH CX ;SAVE SCREEN BOUNDS MOV AH,3 ;WILL NOW READ THE CURSOR. INT 10H ;AND PRESERVE THE POSITION POP CX ;RECALL SCREEN BOUNDS PUSH DX ;RECALL [BH]=VISUAL PAGE XOR DX,DX ;WILL SET CURSOR POSITION TO [0,0] ;******************************************** ; THE LOOP FROM PRI10 TO THE INSTRUCTION PRIOR TO PRI20 ; IS THE LOOP TO READ EACH CURSOR POSITION FROM THE SCREEN ; AND PRINT. ;******************************************** PRI10: MOV AH,2 ;TO INDICATE CURSOR SET REQUEST INT 10H ;NEW CURSOR POSITION ESTABLISHED MOV AH,8 ;TO INDICATE READ CHARACTER INT 10H ;CHARACTER NOW IN [AL] OR AL,AL ;SEE IF VALID CHAR JNZ PRI15 ;JUMP IF VALID CHAR MOV AL,' ' ;MAKE A BLANK PRI15: PUSH DX ;SAVE CURSOR POSITION XOR DX,DX ;INDICATE PRINTER 1 XOR AH,AH ;TO INDICATE PRINT CHAR IN [AL] INT 17H ;PRINT THE CHARACTER POP DX ;RECALL CURSOR POSITION TEST AH,25H ; TEST FOR PRINTER ERROR JNZ ERR10 ; JUMP IF ERROR DETECTED INC DL ;ADVANCE TO NEXT COLUMN CMP CL,DL ;SEE IF AT END OF LINE JNZ PRI10 ;IF NOT PROCEED XOR DL,DL ;BACK TO COLUMN 0 MOV AH,DL ;[AH]=0 PUSH DX ;SAVE NEW CURSOR POSITION CALL CRLF ; LINE FEED CARRIAGE RETURN POP DX ;RECALL CURSOR POSITION INC DH ;ADVANCE TO NEXT LINE CMP CH,DH ;FINISHED? JNZ PRI10 ;IF NOT CONTINUE PRI20: POP DX ;RECALL CURSOR POSITION MOV AH,2 ;TO INDICATE CURSOR SET REQUEST INT 10H ;CURSOR POSITION RESTORED MOV STATUS_BYTE,0 ;INDICATE FINISHED JMP SHORT EXIT ;EXIT THE ROUTINE ERR10: POP DX ;GET CURSOR POSITION MOV AH,2 ;TO REQUEST CURSOR SET INT 10H ;CURSOR POSITION RESTORED ERR20: MOV STATUS_BYTE,0FFH ;INDICATE ERROR EXIT: POP DX ;RESTORE ALL THE REGISTERS USED POP CX POP BX POP AX POP DS IRET PRINT_SCREEN ENDP ;------ CARRIAGE RETURN, LINE FEED SUBROUTINE CRLF PROC NEAR XOR DX,DX ;PRINTER 0 XOR AH,AH ;WILL NOW SEND INITIAL LF,CR TO PRINTER MOV AL,12Q ;LF INT 17H ;SEND THE LINE FEED XOR AH,AH ;NOW FOR THE CR MOV AL,15Q ;CR INT 17H ;SEND THE CARRIAGE RETURN RET CRLF ENDP CODE ENDS ;---------------------------------- ; POWER ON RESET VECTOR ;---------------------------------- VECTOR SEGMENT AT 0FFFFH ;------ POWER ON RESET JMP RESET DB '04/24/81' ; RELEASE MARKER VECTOR ENDS END