reg | description |
---|---|
AH | function request number |
AL | number of sectors (1-128 dec.) |
CH | cylinder number (0-1023 dec.) |
CL | sector number (1-17 dec.) |
DH | head number (0-15 dec.) |
DL | drive number (0=A:, 1=2nd floppy, 80h=drive 0, 81h=drive 1) |
DL | drive number (0=A:, 1=2nd floppy, 80h=C:, 81h=D:) Note that some programming references use (0-3) as the drive number which represents diskettes only. |
ES:BX | address of user buffer |