Enable BIOS caching/shadowing?

Recommended by Wim's BIOS...

When using an NT-based version of Windows (i.e Windows NT/2000/XP), is it a good idea to enable 'System BIOS Cacheable' or similar setting that copies the BIOS into RAM? Please tell me all you know about this.

Thanks.

Some video cards/drivers have specific do & don'ts regarding shadowing.

[NickS]

Great wrote:

When using an NT-based version of Windows (i.e Windows NT/2000/XP), is it a good idea to enable 'System BIOS Cacheable' or similar setting that copies the BIOS into RAM? Please tell me all you know about this.

Thanks.

System BIOS on a modern machine (not on my IBM 286) is copied (or decompressed) into RAM anyway, so the question for System BIOS is only whether or not to make it cacheable. I would say "suck it and see".

Whether other BIOSes such as your video BIOS should be cacheable/ copied to RAM depends. For example, the old Future Domain SCSI controllers used memory-mapped I/O in the BIOS address range and copying that to RAM or caching it meant it stopped working altogether. In general I cache and shadow my video RAM , make my system BIOS cacheable and that's it.

[KachiWachi]

There was a discussion of this over at the PCChips site a while back.

Peter Missel says that all *modern* BIOS's are written to be cacheable, so no matter what you set in the BIOS, they will be anyway.

Perform a search there to find the discussion in question.

[ajzchips]

Written to be cached, or written to be shadowed, or both? I'm starting to have some doubts right now...

I am running XP PRO on a BIOSTAR MoBo with a VIA chipset including an AWARD BIOS and an AMD CPU. The BIOS/CMOS setup for the AWARD has about a page of options on enabling various types of RAM and Shadowing memory schemes plus a variety of specific memory ranges which are useable for BIOS, and other, uses.
One would suspect your chip producer would also have fairly specific guidance. The options in modern BIOSes are astounding compared with those of only even 3 years ago.

[NickS]

LinusF wrote:

The options in modern BIOSes are astounding compared with those of only even 3 years ago.

And yet I can't find "non-cacheable area size/start address" as I have on my 486-VIP-IO mobo's BIOS, which actually allows me to use the Future Domain TMC-845/TMC-850.

And I recently booted to DOS 6.22 to flash my BIOS. What a pleasure it was to rip through on a command line once again. But I digress... LinusF

[KachiWachi]

Perhaps one of the moderators can get Peter to write a short essay on all this to put into the *sticky* area, and end the confusion once and for all??

When he has the time of course...