![background image](http://html.mh-extra.com/html/dtk-computer/apex-386-40/apex-386-40_user-manual_2535909105.webp)
I/O Port Address 72H
1
Data bit 5
Shadow area write protect
0
Shadow area write enable
1
Enable video BIOS shadow
Data
bit 6
0
Disable video BIOS shadow
1
Data bit 7
Enable system BIOS shadow
0
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.
12
Chapter 6: Appendix
Summary of Contents for Apex 386/40
Page 1: ......
Page 13: ...Chapter 1 System Overview ...
Page 36: ...Chapter 2 Setting Up Your System ...
Page 54: ...Chapter 3 Operating Your System ...
Page 74: ...Capter 4 Keyboard ...
Page 84: ...Chapter 5 Troubleshooting ...
Page 93: ...Chapter 6 Appendix ...
Page 109: ...Chapter 7 Glossary ...