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> Main > lpt to lcd drive |
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revolution 26 Jun 2010, 12:25
Your delay is very suspect. It relies heavily on the CPU speed to be within range.
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26 Jun 2010, 12:25 |
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edfed 26 Jun 2010, 22:25
yeah, i believe it too, but i didn't had the time to seek the better way, i've made a little mistake that induced one complete praogrammer-day. r/w signal was not on the right bit in lpt.
i pointed to pin 17 insted of pin 14, that's why i've tryed a lot of various delays before to see the horrible mistake. one more time, the error is the teatcher |
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26 Jun 2010, 22:25 |
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edfed 06 Jul 2010, 18:17
this code:
Code: ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; org 100h @@: call init ;@@: rdtsc mov [tsc],eax mov [tsc+4],edx mov ax,0 call lcd.goto mov bx,0 mov edx,[tsc+4] call hexa mov edx,[tsc] call hexa call refresh ; mov si,message ; call puts ;@@: in al,60h cmp al,39h ;espace je @f jmp @b @@: mov ax,3 int 10h ret ;;;;;;;;;;; ;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;; tsc dd 0,0 message: .0: db '0123456789abcdef' .1: db 'c:/>fool/tetris ' .2: db 'this code needs ' .3: db ' graphic screen ' .pad: db ' ' .end: ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; refresh: mov si,0 @@: mov ah,[si] call putc inc si cmp si,message.1 jne @b mov si,message.2 @@: mov ah,[si] call putc inc si cmp si,message.3 jne @b mov si,message.pad @@: mov ah,[si] call putc inc si cmp si,message.end jne @b mov si,message.1 @@: mov ah,[si] call putc inc si cmp si,message.2 jne @b mov si,message.3 @@: mov ah,[si] call putc inc si cmp si,message.pad jne @b ret ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; puts: @@: mov ah,[si] cmp ah,0 je @f call putc inc si jmp @b @@: ret ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; hexa: mov cx,8 @@: rol edx,4 mov al,dl and al,0fh cmp al,10 sbb al,069h das mov ah,al mov [bx+message],ah inc bx loop @b ret ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; putc: push eax ebx ecx edx call lcd.writedatacheck pop edx ecx ebx eax ret ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; init: call delay40 mov ah,38h ;function set call lcd.writeinstnocheck call delay37 mov ah,0ch ;display on call lcd.writeinstcheck call delay37 call lcd.clear mov ah,6 ;entry mode set call lcd.writeinstcheck call delay37 ret ;--------------------------------------------------------------------------------- ;LPT connection ;pin 1 = E = .ctrl bit0, 1 inverted ;pin 14 = R/W = .ctrl bit1, 2 inverted ;pin 16 = RS = .ctrl bit2, 4 ;pins 2 to 9 = data = .data ; ;LCD connection ;pin 1 = gnd ;pin 2 = +5V ;pin 3 = contrast ;pin 4 = Register Select ;pin 5 = Read /Write ;pin 6 = Enable ;pins 7 to 14 = data ;--------------------------------------------------------------------------------- macro delay .t { mov ecx,.t*1000 @@: dec ecx jne @b } delay40: delay 3000 ret delay37: delay 200 ret delay1520: delay 20 ret ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; lcd: .lpt=378h .data=.lpt+0 .stat=.lpt+1 .ctrl=.lpt+2 .e=1 .rw=2 .rs=4 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; .p1: mov dx,lcd.data ret ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; .p2: mov dx,lcd.stat ret ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; .p3: mov dx,lcd.ctrl ret ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; .goto: ;al=x ;ah=y cmp ah,1 jne @f add al,40h @@: cmp ah,2 jne @f add al,10h @@: cmp ah,3 jne @f add al,50h @@: or al,80h call .writeinstcheck ret ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; .clear: mov ah,1 call lcd.writeinstcheck call delay1520 ret ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; .writedatacheck: call .busycheck .writedatanocheck: call .dr call .wr call .en call .p1 mov al,ah out dx,al call delay1520 call .dis call .p1 mov al,0ffh out dx,al ret ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; .writeinstcheck: call .busycheck .writeinstnocheck: call .ir call .wr call .en call .p1 mov al,ah out dx,al call delay1520 call .dis call .p1 mov al,0ffh out dx,al ret ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; .busycheck: call .ir call .rd call .en call .busy ; call delay37 call .dis ret .busy: call .p1 @@: in al,dx and al,80h je @b ret ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; .dr: .datareg: call .p3 in al,dx or al,.rs out dx,al ret ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; .ir: .instreg: call .p3 in al,dx and al,not .rs out dx,al ret ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; .dis: .disable: call .p3 in al,dx or al,.e out dx,al ret ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; .en: .enable: call .p3 in al,dx and al,not .e out dx,al ret ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; .wr: .write: call .p3 in al,dx or al,.rw out dx,al ret ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; .rd: .read: call .p3 in al,dx and al,not .rw out dx,al ret ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; gives this result:  |
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06 Jul 2010, 18:17 |
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shoorick 07 Jul 2010, 08:45
cool! my 20-years old dream
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07 Jul 2010, 08:45 |
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revolution 07 Jul 2010, 08:49
Why doesn't the first line write correctly?
Code: .0: db '0123456789abcdef' |
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07 Jul 2010, 08:49 |
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edfed 07 Jul 2010, 09:26
it is replaced by the rdtsc value. in order to see the real time-ness of the refresh routine.
the value currentlly displayed tells me the 600MHz CPU works since 50 minutes. now, i will need to cut this code in order to make it work via the PIT interrupt. it is more interresting to play with a buffer (message) and refresh periodically the lcd, than to play with LCD and commands. then, only few functions of the lcd are used. it simplifiez the code. finally, this little lcd will be used on my first computer (i still have it!!!) PMMX, 233MHz. it will be used as text mode viewer. the text mode memory at 0b8000h will be copied to the lcd buffer. or the last 4 lines including the line with the cursor. then, i will not need a screen on this compuer as it is intended to become a netwok bridge under linux or bsd. |
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07 Jul 2010, 09:26 |
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edfed 09 Jul 2010, 09:56
i have this too. it is a synaptics touch pad, PS/2 and perhaps USB compatible...
only 4 wires needed. GND, VCC, CLK and DATA. then, maybe it can be handled by the LPT port, via LPT interrupt pin wired to clk pin of the touch pad, and data pin connected to any input of the lpt port.  |
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09 Jul 2010, 09:56 |
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