<8Gb Int 13H Functions (Conventional Functions); Table 6 - Conventional Register Definitions - Western Digital T13/2132-D User Manual

June 23, 2010
5 <8GB INT 13h Functions (Conventional Functions)
The Conventional INT 13h functions can address a maximum of 8.4GB of device space. Sector sizes shall be
exactly 512 bytes. The Conventional INT 13h functions pass all parameters in registers using the following
template (see table 6) unless otherwise specified:
Register
AH INT 13h function number (Range is 00h through 3Fh)
AL Number of sectors to transfer
CH Low 8 bits of Cylinder
CL
Bit Description
5:0 Sector number. This value shall be >= 01h and <= 3Fh
7:6 High order 2 bits of the cylinder
DH Head Number
DL
Bit Description
6:0 Drive number
7 Set to 1 for Fixed media, clear to 0 for removable media
ES:BX This register contains the buffer pointer (i.e., the beginning address of the buffer in system memory).
Commands that move data from the device to memory shall use this pointer as the destination for
the data. Commands that move data from memory to the device shall use this pointer as the source
for the data to be transferred.
Working Draft Enhanced Disk Drive - 4 (EDD-4)
Table 6 — Conventional Register Definitions
Description
T13/2132-D Revision 3
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