Chapter 2 WINBIOS Setup
Chipset Setup,
Continued
ISA VGA USWC/Video Frame Buffer
This option specifies the starting address of the VGA video frame buffer using
USWC.
USWC is Uncacheable, Speculatable, Write – Combined memory.
The settings are:
Setting
Description
Disabled
No VGA video frame buffer is available.
A0000h
The system memory segment beginning at A0000h is used for
the VGA USWC/video frame buffer.
B0000h
The system memory segment beginning at B0000h is used for
the VGA USWC/video frame buffer.
Both
The 128 KB of system memory from A0000h through BFFFFh
is used for the VGA USWC/video frame buffer.
VGA card drivers may not behave correctly when this option is not set to
Disabled. The Optimal and Fail – Safe default settings are Disabled.
PCI VGA USWC/Video Frame Buffer
Set this option to Enabled to enable the USWC memory attribute and improve
video performance when a PCI video adapter is installed. However, VGA card
drivers may not behave correctly when this option is set to Enabled. The
settings are Disabled or Enabled. The Optimal and Fail – Safe defaults are
Disabled.
Optional ROM
The Merlin DP PCI Pentium Pro motherboard has an empty option ROM socket
near the ISA expansion slots. You can install a 32 KB ROM in this socket. The
starting memory address of this ROM can be either C000h (only if this
computer does not have a VGA controller), C800h, D000h, or D800h. The
following three Chipset Setup options configure the option ROM only if you
have installed a ROM chip in the option ROM socket.
Optional ROM Decode
This option specifies the starting address of an adapter ROM to be decoded.
The settings are C000h, C800h, D000h, D800h, or Disabled. The Optimal and
Fail – Safe defaults are Disabled.
Cont’d