Interrupt Routines - Sanyo MBC-550 Series User Manual

INTERRUPT ROUTINES
Interrupt 13
Diskette I/O
This interface provides access to the 5 1/4"
diskette drives.
Input
(AH) = 0 Reset diskette system
Hard reset to nec, prepare command, recal
reqd on all drives
(AH) = 1 Read the status of the system into (AL)
Diskette status from last op'n is used
Registers for READ/WRITE/VERIFY/FORMAT
(DL) - Drive number (0-3 allowed, value checked)
(DH) - Head number (0-1 allowed, not value check­
ed)
Track number (0-39, not value checked)
Sector number (1-8, not value checked)
Number of sectors (max = 8
checked)
(CH) -
(CL) -
(AL) -
not value
(ES:BX) - Address of buffer (not required for
verify)
(AH) = 2 Read the desired sectors into memory
(AH) = 3 V/rite the desired sectors from memory
(AH) = 4 Verify the desired sectors
Data variable — Disk pointer
Double word pointer to the current set of diskette
parameters
Output
AH = Status of operation
Status bits are defined in the equates for
5—19