Chapter 4 System Support
Compaq Deskpro 4000 and 6000 Personal Computers
featuring the Pentium II Processor
First Edition - October 1997
4-50
4.8.7 COVER REMOVAL SENSOR
This system includes a cover removal indication function. The system can, upon power-up,
notify the user if the computer cover has been removed. The sensor consists of a plunger switch
mounted on the backplane (riser card) that comes in contact with the chassis cover. When the
cover is removed, the switch is activated and the battery-backed logic places a high at GPIO port
1bit <4>. This bit will remain set (whether or not the cover is replaced) until the system is
powered up and the user completes the boot sequence successfully, at which time the hood alarm
bit <4> will be cleared. Through Setup, the user can set this function to one of three levels of
support for a “hood removed” condition:
Level 0 - Hood removal indication is essentially disabled at this level. During POST, Bit <4> is
cleared and no other action is taken by BIOS.
Level 1 - During POST the message “The computer’s cover has been removed since the last
system start up” is displayed and time stamps in CMOS and SIT are updated.
Level 2 - During POST the “The computer’s cover has been removed since the last system start
up” message is displayed, time stamps in CMOS and SIT are updated, and user is prompted for
administrator password.
NOTE:
If the user invokes Setup through F10 the administrator password is not
requested again.
The System Information Table (SIT) record format for the hood removal time stamp is as
follows:
System Information Table, System Hood Removal Record (13h)
Byte Bit Function
00h 7-0 Record ID (13h)
01h 7-0 Length of record
02-05h
31-25
24-21
20-16
15-11
10-5
4-0
Hood Removal Time Stamp:
Year (0-99, representing 1996-2095)
Month (1-12)
Day (1-31)
Hours (0-23)
Minutes (0-59)
Seconds (0-59)
06h 7-0 Hood Removal Support Enable/Disable Byte Offset (0-255)
07h
7..4
3..0
Hood Removal Support Enable/Disable Bit Location:
CMOS Type (0011b, use INT 15h for flat model CMOS)
Bit location (0000b)
08h 7..0 Hood Removal NOBOOT Enable/Disable Byte Offset (0-255)
09h
7..4
3..0
Hood Removal NOBOOT Enable/Disable Bit Location:
CMOS Type (0011b, use INT 15h for flat model CMOS)
Bit location (0001b)
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