Compaq 4000N User Manual

Page 144

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Chapter 8 BIOS ROM

Compaq Deskpro 4000N and 4000S Personal Computers

First Edition - September 1997

8-4

8.3.2.1

INT 15, AX=E841h, BL=00h - Set CMOS Defaults

This function sets a bit in NVRAM that instructs the BIOS to load NVRAM with default values
during the next system boot. The user will not be prompted when the default values are set. Note
that the ESCD area of NVRAM is not affected by this function. Any required changes to the
ESCD area must be made by the calling application invoking PnP BIOS functions.

INPUT:

EAX

= E841h

BH

= 00h

OUTPUT:
(Successful)

CF

= 0

AH

= 00h

(Failure)

CF

= 1

AH

= 86h, Function not supported

8.3.2.2

INT 15, AX=E841h, BL=01h - Set System Board Device Defaults

This function performs a PnP Set System Device Node call for all system board “devnnodes.” On
the next boot following execution of this function, each device is configured with the factory
default settings. In addition to this call, an application may choose to also remove non-system
board devices from ESCD area. The function is described as follows:

INPUT:

EAX

= E841h

BH

= 00h

OUTPUT:
(Successful)

CF

= 0

AH

= 00h

(Failure)

CF

= 1

AH

= 86h, Function not supported

8.3.3

ACCESSING CMOS FEATURE BITS

The BIOS function INT 15, AX=E845h is used for accessing areas in non-volatile memory used
to store variables for various features. This is a Client Management function and is described in
section 8.4.

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