Write Sectors From Memory (Fn 03H) - Western Digital T13/2132-D User Manual

June 23, 2010

8.5 Write Sectors From Memory (FN 03h)

This function shall be used to transfer data from the host buffer beginning at the location specified by the
contents of the ES:BX registers.
Entry
AH 03h
AL Number of sectors to write, shall be greater than 0 and less than 128
CH Low order 8 bits of the cylinder number
CL
DH Head number
DL BIOS device number
ES:BX Pointer to source buffer in memory
Exit
Carry Clear Function completed without error
Carry Set Function completed with an error
Working Draft Enhanced Disk Drive - 4 (EDD-4)
Bit Description
7:6 high order 2 bits of the cylinder
5:0 sector number
AH Shall be cleared to zero
AL Number of sectors written
AH Shall be set to the error code
AL Vendor Specific
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