Int 13H [PC] [AT] [PS/2] Function 0BH (11) Write sector long

Writes a sector or sectors from memory to disk. Each sector's worth of data must be followed by its 4-byte ECC code.

Call with:

AH = 0BH

AL = number of sectors

CH = cylinder

CL = sector (see Notes)

DH = head

DL = drive

80H—FFH fixed disk

ES:BX = segment:offset of buffer

Returns:

If function successful

Carry flag = clear

AH = 00H

AL = number of sectors transferred

If function unsuccessful

Carry flag = set

AH = status (see Int 13H Function 01H)

Notes:

This function is supported on fixed disks only.

The upper 2 bits of the 10-bit cylinder number are placed in the upper 2 bits of register CL.