User`s manual

DIGITAL-LOGIC AG MSLB-P5 Manual V0.3
PRELIMINARY 168
16.6.3 Interrupt 11h–Return System Information
This service returns the equipment installed as determined by the BIOS on power-up diagnostics and
stored in the BIOS Data Area.
Interrupt 11 Return System Information
Exit:
AX Equipment information:
Bit Definition
0 Not used
1 Math coprocessor installed
2 PS/2 mouse installed
3 Not used
4,5 Initial video mode:
00 = EGA/VGA
01 = 40x25 CGA
10 = 80x25 CGA
11 = Monochrome
6,7 Diskette drives:
00 = 1 drive
01 = 2 drives
10 = 3 drives
11 = 4 drives
8 Not used
9-11 Number of serial adapters
12 Game Adapter installed
13 Not used
14,15 Number of parallel adapters
16.6.4 Interrupt 12h–Return Memory Size
Returns the amount of system memory determined during the power on diagnostics.
Interrupt 12 Return System Memory Size
Exit:
AX Number of 1-kilobyte memory blocks
16.6.5 Interrupt 13h–Diskette Services
Interrupt 13 is the BIOS software interface for access to the 5-¼" and 3-½" inch diskette drives. When
there is a fixed disk in the system, the BIOS assigns Interrupt 13h to the fixed disk and routes diskette
calls to Interrupt 40h.
The following table lists the AH error codes.
Int 13 Diskette Exit Status Codes
AH 00h = No error
If Carry = 1:
AH 01h = Illegal BIOS command
02h = Bad address mark
03h = Write-protect occurred
04h = Sector not found
06h = Media changed
09h = DMA crossed 64K boundary
08h = DMA failed
0Ch = Media not found
10h = CRC failed
20h = NEC failed
30h = Drive does not support media sense
31h = No media in drive
32h = Drive does not support media type
40h = Seek failed
80h = Time out occurred