User`s manual

I/O Port Address 72H

Data bit 5

Shadow area write protect

Shadow area write enable

Enable video BIOS shadow

Data

bit 6

Disable video BIOS shadow

Data bit 7

Enable system BIOS shadow

Disable system BIOS shadow

Figure 6-10:

Shadow RAM Control Port

lf you use DTK BIOS, you can enable or disable these two shadow

RAM functions through your BIOS setup.

Note:

1. If your adapter uses extended memory area as non-cacheable

memory in the same way as dual-port memory, you have to configure

the non-cacheable memory after the cacheable area is set by means

of SW1 --1-3.

2. lf your adapter BIOS is located at 0C8000H-0CFFFFH (within

0C0000H-0CFFFFH) and cannot be cached, you should move the

address to a noncacheable area like 0D0000H-0DFFFFH or disable

the video shadow function.

3. Cacheable area means physical 32-bit memory installed area and

shadow RAM area (0F0000H —

0FFFFFH, 0C0000H — 0CFFFFH) if

installed.

Chapter 6: Appendix