Int 13/AH=05h

FIXED DISK - FORMAT TRACK

AH = 05h
AL = interleave value (XT-type controllers only)
ES:BX -> 512-byte format buffer
the first 2*(sectors/track) bytes contain F,N for each sector
F = sector type
00h for good sector
20h to unassign from alternate location
40h to assign to alternate location
80h for bad sector
N = sector number
CH = cylinder number (bits 8,9 in high bits of CL)
CL = high bits of cylinder number (bits 7,6)
DH = head
DL = drive

Return:
CF set on error
CF clear if successful
AH = status code (see #00234)

Notes: AWARD AT BIOS and AMI 386sx BIOS have been extended to handle more than 1024 cylinders by placing bits 10 and 11 of the cylinder number into bits 6 and 7 of DH. For XT-type controllers on an AT or higher, AH=0Fh should be called first. The IBM AT BIOS and many other BIOSes use only the low four bits of DH (head number) since the WD-1003 controller which is the standard AT controller (and the controller that IDE emulates) only supports 16 heads. Not all controller support sector types 20h and 40h. Under Windows95, an application must issue a physical volume lock on the drive via INT 21/AX=440Dh before it can successfully write to the disk with this function

See Also: AH=05h"FLOPPY" - AH=06h"FIXED" - AH=07h"FIXED" - Category: Bios - Int 13h - F

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