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System id and rom type, Edid retrieve, 1 system id and rom type – HP D315 User Manual

Page 147: 2 edid retrieve

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Technical Reference Guide

8.5.1 SYSTEM ID AND ROM TYPE


Applications can use the INT 15, AX=E800h BIOS function to identify the type of system. This
function will return the system ID in the BX register. These systems have the following IDs and
ROM family types:

System

System ID

ROM Family

PnP ID

Compaq D315 Personal Computer

07D0h

686Y4

CPQ0047

Compaq D325 Personal Computer

0830h

786A5

CPQ0059


The ROM family and version numbers can be verified with the Setup utility or the Compaq
Insight Manager or Diagnostics applications.

8.5.2 EDID RETRIEVE


The BIOS function INT 15, AX=E813h is a tri-modal call that retrieves the VESA extended
display identification data (EDID). Two subfunctions are provided: AX=E813h BH=00h retrieves
the EDID information while AX=E813h BX=01h determines the level of DDC support.

Input:

AX =

E813h

BH

= 00 Get EDID .

BH

= 01 Get DDC support level

If BH = 00 then
DS:(E)SI = Pointer to a buffer (128 bytes) where ROM will return block
If 32-bit protected mode then
DS:(E)SI = Pointer to $DDC location

Output:
(Successful)

If BH

= 0:
DS:SI=Buffer with EDID file.

CX

= Number of bytes written

CF =

0

AH

=00h Completion of command


If BH

= 1:

BH

= System DDC support
<0>=1 DDC1 support
<1>=1 DDC2 support

BL

= Monitor DDC support
<0>=1 DDC1 support
<1>=1 DDC2 support
<2>=1 Screen blanked during transfer

(Failure)

CF =

1

AH

= 86h or 87h

Compaq D315 and hp d325 Personal Computers

Featuring the AMD Athlon XP Processor

Second Edition – April 2003

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