T13/2132-D Revision 3 June 23, 2010
44 Working Draft Enhanced Disk Drive - 4 (EDD-4)
8.16 Extended Write (FN 43h)
This function shall transfer sectors from memory to the device. If the device does not support the WRITE
VERIFY command, this function rejects the request with AH = 01h and CF = 1b. FN 48h shall be used to detect
if the device supports the WRITE VERIFY command. In the event of an error, the block count field of the device
address packet contains the number of blocks transferred before the error occurred. The calling software should
not assume that the data transferred is validly written to the media. AL also contains the values 00h, 01h, or 02h.
This function rejects all other values with AH = 01h and CF = 1b.
Entry
AH 43h
AL
Value Description
00h write with no verify operation
01h write with no verify operation
02h write with verify operation
03h-FFh Reserved
DL BIOS device number
DS:SI Pointer to Device Address Packet (see table 9)
Exit
Carry Clear Function completed without error
AH Shall be cleared to zero
Carry Set Function completed with an error
AH Shall be set to the error code