Resets the disk controller, recalibrates its attached drives (the read/write arm is moved to cylinder 0), and prepares for disk I/O.
Call with:
AH = 00H
DL = drive
00H—7FH floppy disk
80H—FFH fixed disk
Returns:
If function successful
Carry flag = clear
AH = 00H
If function unsuccessful
Carry flag = set
AH = status (see Int 13H Function 01H)
Notes:
This function should be called after a failed floppy disk Read, Write, Verify, or Format request before retrying the operation.
If called with DL >= 80H (i.e., selecting a fixed disk drive), the floppy disk controller and then the fixed disk controller are reset. See also Int 13H Function 0DH, which allows the fixed disk controller to be reset without affecting the floppy disk controller.