INT 13h,  17h (23)       Set DASD Type for Format                        many

This service sets the type of diskette for a particular type of drive
in order that the disk is properly formatted. This service can be
performed on diskettes only.

On entry:      AH         17h
AL         Diskette/drive combination (see below)
DL         Drive number (bit 7 must be clear)

Returns:       CF         Set if error, else cleared
AH         Status of operation (see Service 01h)

                    Diskette/Drive Combination
               AL         Meaning
01h        Diskette 320/360K in 360K drive
02h        Diskette 360K in 1.2M drive
03h        Diskette 1.2M in 1.2M drive
04h        Diskette 720K in 720K drive

Notes:         This service is not available for PCs, PCjrs, and
XTs dated before 1/10/86.

A diskette/drive combination value of 04h is not
valid for ATs before 6/10/85.

For the AT, XT-286, and PC Convertible, the BIOS
executes INT 15h, Service 90h (Device Busy), for the
diskette (Type = 01h) prior to waiting for the
interrupt. INT 15h, Service 91h (Interrupt
Complete), is executed upon completion. Diskette
operations that require the diskette motor to be on
will call INT 15h, Service 90 (Device Busy), with
the type equal to "Diskette Drive Motor Start" (Type
= FDh). This allows the system to perform another
task while the drive motor is waiting to get up to

See also: INT 13h, 01h
See also: INT 13h, 15h
See also: INT 13h, 16h

INT 13h, 17h (23) Set DASD Type for Format many