Compaq EN Series - Page 91

Chapter 4 System Support
Compaq Deskpro EN Series of Personal Computers
Desktop and Minitower Form Factors
Third Edition - September 1998
4-42
Configuration Byte 90h, 91h, Total Super Extended Memory Configured
This byte holds the value of the amount of extended system memory that is configured.
The amount is given in 64-KB increments.
Configuration Byte 92h, Miscellaneous Configuration Byte
Default Value = 18h
Bit Function
7..5 Reserved
4 Diskette Write Control:
0 = Disable
1 = Enable
3..1 Reserved
0 Diskette Drive Swap Control:
0 = Don’t swap
1 = Swap drive A: and B:
Configuration Byte 93h, PCI Configuration Byte
Default Value = 00h
Bit Function
7 Onboard SCSI Status:
0 = Hidden
1 = Active
6 Onboard NIC Status:
0 = Hidden
1 = Active
5 Onboard USB Status:
0 = Hidden
1 = Active
3 Reserved
2 ISA Passive Release:
0 = Enabled
1 = Disabled
1 PCI Bus Master Enable
0 = Enabled
1 = Disabled
0 PCI VGA Palette Snoop
0 = Disable
1 = Enable
If palette snooping is enabled, then a primary PCI graphics card may share a common palette
with the ISA graphics card. Palette snooping should only be enabled if all of the following
conditions are met:
♦
An ISA card connects to a PCI graphics card through the VESA connector.
♦
The ISA card is connected to a color monitor.
♦
The ISA card uses the RAMDAC on the PCI card
♦
The palette snooping feature (sometimes called “RAMDAC shadowing”) on the PCI card is
enabled and functioning properly.