System Id And Rom Type; Edid Retrieve - Compaq Deskpro Workstation AP230 Technical Reference Manual

Chapter 8 BIOS ROM

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
Small Form Factor:
w/815E-based graphics
w/NVIDIA graphics
Slim Desktop/Configurable Minitower
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
BH
BH
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
CX
CF
AH
If BH
BH
BL
(Failure)
CF
AH
8-14 Compaq Deskpro Personal Computers
System ID
688h
680h
684h
= E813h
= 00 Get EDID .
= 01 Get DDC support level
= 0:
DS:SI=Buffer with EDID file.
= Number of bytes written
= 0
=00h Completion of command
= 1:
= System DDC support
<0>=1 DDC1 support
<1>=1 DDC2 support
= Monitor DDC support
<0>=1 DDC1 support
<1>=1 DDC2 support
<2>=1 Screen blanked during transfer
= 1
= 86h or 87h
Third Edition - April 2001
ROM Family PnP ID
686P2 CPQ0004
686P3 CPQ0003
686P2 CPQ0005