Where is the misstake?

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joachim_neu

Joined: 22 Dec 2003
Posts: 139

joachim_neu 02 Mar 2004, 20:04

Hello,

this code should load 5 sectors from the drive and write it into the monitor. But it don't work... There comes only a beep in WIN and then it ends... This is the code:

Code:


; Load
load:

; Diskdrive reset (Interrupt 13h, 0)
push ds            ; Save DS
mov ax, 0          ; The function (reset)
mov dl, 0          ; This drive
int 13h            ; run the interrupt
pop ds             ; DS recover
jc load            ; Misstake? Again!

load1:
mov ax,0x1000      ; ES:BX = 10000
mov es,ax
mov bx, 0

; read sectors (Interrupt 13h, 2)
mov ah, 2       ; Function 2 (Lesen)
mov al, 5       ; read 5 Sectors
mov cx, 2       ; Cylinder=0, Sector=2
mov dx, 0       ; Head=0, Laufwerk=0
int 13h         ; ES:BX =  Dates of the drive
jc load1        ; misstake? again!

mov ax,0x1000
mov es,ax
mov BP, 0
mov AH,13h
mov AL,0h
mov BL,0h
mov BH,0h
mov CX,0xA00
mov DH,0
mov DL,0
int 10h

please help me, I don't find the misstake...

JOACHIM NEU

02 Mar 2004, 20:04

S.T.A.S.

Joined: 09 Jan 2004
Posts: 173
Location: Ru#27

S.T.A.S. 03 Mar 2004, 07:59

I guess you have win NT/2k/XP

03 Mar 2004, 07:59

Rookie

Joined: 21 Aug 2003
Posts: 44
Location: Planet Romania

Rookie 03 Mar 2004, 09:02

Int the NT series, and later 2K&up, you do not have direct access to the system's resources (including access to physical sectors of your HDD), and this is exactly what you are trying to do, as you are using interrupts, not the Windows API. If you don't have a Win9x distribution, a DOS diskette should suffice (if you don't have one of that either, just goolge for 'Win98SE Startup Disk' and download an FD image that you can either write to a FD or use in virtual machine software like Bochs).
Plus, mistake is spelled with only one s (you asked us to let you know about your mistake).

I know all I've done is repeat what S.T.A.S. said, but when you're 13 and learning programming you have a lot of why-s in your head, that need ample answers (at least I had).

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This is who I choose to be.

03 Mar 2004, 09:02

joachim_neu

Joined: 22 Dec 2003
Posts: 139

joachim_neu 03 Mar 2004, 15:49

hello,

i startet the programm with a DOS-floppy but it still didn't work. it seems that it is writing on the monitor and the cursor jumps, but there comes only black in stead of white text or letters... mybe you can help me again...

JOACHIM NEU

03 Mar 2004, 15:49

S.T.A.S.

Joined: 09 Jan 2004
Posts: 173
Location: Ru#27

S.T.A.S. 04 Mar 2004, 21:34

Hi, joachim_neu.

Your program consist of two patrts. The first step to solve problem is to localize it.
Try to fill your buffer with some ASCII chars, don't read from drive.
If you'll see some symbols on screen, then problem is with reading sectors.
Otherwise, there's something wrong with your last call to BIOS.
I'm not sure why you use "mov BH,0h". Also, what does 0h in "mov BL,0h" mean for int 10h/AH=13h?

04 Mar 2004, 21:34

joachim_neu

Joined: 22 Dec 2003
Posts: 139

joachim_neu 05 Mar 2004, 11:33

hello,

my code was right, the only mistake was that I set BX in the outputpart in 0h, so that that, what was written onto the monitor was in black letters and on black background, so you couldn't see it... But how may I write a string into the ram, my buffer???

05 Mar 2004, 11:33

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