Compaq Deskpro 4000N Technical Reference Manual page 76

Chapter 4 System Support
Configuration Byte 45h, Keyboard Snoop Data
Default Value = xxh
Bit Function
7 Cntrl/F10 Key Status:
0 = Cntrl & F10 keys not pressed
1 = Cntrl & F10 keys pressed
6 F10 Key Status:
0 = F10 key not pressed
1 = F10 key pressed
5..1 Reserved
0 Key Pressed Flag:
0 = Key not pressed
1 = Key pressed
Configuration Byte 46h, Diskette/Hard Drive Status
Default Value = xxh
Bit Function
7,6 Reserved
5 Partition On HD:
0 = Not set, 1 = Set
4 Setup Disk:
0 = Not present, 1 = Present
3 ROMPAQ or DIAGS Diskette:
0 = Not present, 1 = Present
2 Boot Diskette in Drive A:
0 = No, 1 = Yes
1 Drive B: Present:
0 = Not present, 1 = Present
0 Drive A: Present:
0 = Not present, 1 = Present
Configuration Bytes 47h-4Fh, IPL Data
These bytes hold initial program load (IPL) data for boot purposes:
Byte 47h, last IPL device
Bytes 48h-4Bh, IPL priority
Byte 4Ch-4Fh, BCV priority
Configuration Byte 51h, ECC Status Byte
Default Value = xxh
Bit Function
7 ECC Status for DIMM 3
6 ECC Status for DIMM 2
5 ECC Status for DIMM 1
4 ECC Status for DIMM 0
3..0 Reserved
4-34 Compaq Deskpro 4000N and 4000S Personal Computers
First Edition - September 1997