INT 13H 04H: Verify Sectors
[PC] [XT] [AT]
Expects: AH 04H
AL sector count (see notes)
CH track (cylinder) number (0-n) <Ķ»
CL sector number (1-n) <ĶĶĶĶĶĶĶĶĶĶĶŹĶĶ (see notes)
DL drive: 0-3=diskette; 80H-81H=hard disk
DH head number
Returns: AH BIOS disk error code if CF is set to CY
Info: This verifies that the CRC^ was correct for the specified
sector(s). It does NOT actually compare disk data to memory.
Notes: ž CX is used as a 6-bit and 10-bit field to specify sector and
cylinder. See INT 13H 02H for details.
ž On diskette writes, this function stops a multi-sector
operation at the last sector in a track.
ž On hard disks (with XT and AT BIOSes), a multi-sector operation
continues on the next higher head of the same cylinder and if
necessary, advances to the next higher cylinder on the first
ž Parameters are the same as for INT 13H 02H (read sectors).
See Also: DOS fn 440dH 62H (IOCTL verify track)
INT 13H: BIOS Disk I/O