Mar 19, 2013 · load: ; Load sectors routine : bootdrv-drive , snum-sectors to load ;ES:BX where to load ex: mov ax,0000h mov es,ax mov bx, 7c00h push bx push ds mov verify,0h .reset: cmp verify,5h je Err1 add verify,1h mov ax, 0 ; Reset Disk mov dl, [BootDrv] ; Drive to reset int 13h ; jc .reset ; Failed -> Try again pop ds pop bx mov verify,0h .read: cmp ...

Apr 3, 2022 · To get around this, BIOSes started providing int 13h extensions which is a 64-bit LBA like number used by the operating system to access the hard drive. But before that became standard, a workaround was created where the BIOS would provide fake int 13h geometry and translate it in to real hard drive CHS geometry or use LBA to access the hard drive.

Feb 17, 2013 · My goal is to, simply put, use Int 13h to read my disk parameters. I understand this can not be directly accomplished in Windows, as it essentially intercepts the BIOS call. My thinking, thus far, is that I can rewrite the code in memory location at 0x7C00h, and utilize Int 19h to do a warm reboot, which would jump to the now overwritten 0 ...

Mar 28, 2012 · So far i have this: mov ah,02h mov cl,11001100001111011101000b ;6,692,584 in dec mov dl,0 int 13

Jan 23, 2010 · The only time int 13h would be used would be during boot stage BEFORE windows loads or if you are using MSDOS as the system i.e. no windows, just boot into MSDOS, then the int 13h would be valid to use. In both cases, they would be 16bit mode and hence the BIOS would be accessible.

Jun 20, 2020 · All the non extended BIOS disk services like Int 13h/AH=2h, Int 13h=AH=3h etc. are all assumed to be 512 byte sectors. There is translation done if the underlying media happens to use a larger disk sector size. Sector sizes will be …

Nov 3, 2023 · The tutorial I am following contains errors, I added mov dl,0 in order to debug the code Can I have a concrete example of Int 13H AH=00h An example coded in nasm on a processor operating in 16 BITS mode So that I can understand it in practice it is necessary that Int 13H AH=00h has an influence on the code, that if I remove it it causes an ...

Jan 1, 2010 · I understand that INT 13h and 25h do not work in the windows protected mode and i even tried my code in Dos but the dos system hangs when I run the program. This is the code: MOV byte ptr es:[bx], offset result MOV AL,1 ;number ofsectors to read MOV Cl,1 MOV ch,0 mov dl,80h ;the HDD mov dh,1 mov ah,02h INT 13h

Sep 23, 2012 · With int 10h, the BL register is used for the colour attributes. Unless you're dealing with CGA, where the BL value is the palette number, the BL value is a number representing the foreground color (4 bits - low part) and the background color (4 bits - high part).

Mar 19, 2017 · I've been writing a test program in NASM for a function that uses int 13h to read sectors off the booted disk except every time I run the assembled program with sudo qemu-system-i386 load_disk.bin it gives me this output: disk read error! disk read error! disk read error!* disk read error!* disk read error!*