Technical Reference Guide
Compaq Deskpro 4000N and 4000S Personal Computers
First Edition - September1997
4-35
Configuration Byte 52h, Board Revision
This byte holds the board revision as copied from the boot block sector.
Configuration Byte 53h, 54h, SW SMI Command/Data Bytes
Configuration Byte 55h, APM Command Byte
Configuration Byte 56h, Miscellaneous Flags Byte
Bit Function
7 CAS Latency:
0 = 2, 1 = 3
6 IR Port Enable Flag:
0 = Disabled (COM2 config. for standard serial port)
1 = Enabled (COM2 config. for IrDA)
5 Warm Boot Enable Flag:
0 = Disable, 1 = Enable
4 POST Terse/Verbose Mode
0 = Verbose, 1 = Terse
3..1 Erase Ease Keyboard Mode:
000 = Backspace/Spacebar
001 = Spacebar/Backspace
010 = Spacebar/Spacebar
011-111 = Invalid
0 Configurable Power Supply:
0 = Power switch active
1 = Power switch inhibited
Configuration Byte 57h-76h, CMOS Copy
Configuration Bytes 77h-7Fh, Administrator Password
Configuration Byte 80h, CMOS Diagnostic Flags Byte
Default Value = 00h. Set bit indicates function is valid.
Bit Function
7 CMOS Initialization (Set CMOS to Default)
6 Setup password locked
5 PnP should not reject SETs because Diags is active
4 Reserved
3 Manufacturing diagnostics diskette found
2 Invalid electronic serial number
1 Boot maintenance partition once
0 Invalid CMOS checksum
Configuration Byte 81h, 82h, Total Super Extended Memory Tested
This byte holds the value of the amount of extended system memory that tested good during
POST. The amount is given in 64-KB increments.