[comp.sys.ibm.pc] 386 with 640-1024 non-mappable

boyer@iuvax.cs.indiana.edu (Charles David Boyer) (02/17/90)

I am looking at a 386-25Mhz motherboard with an AMI bios.
The Documentation states that the area from 640K to 1Meg can ONLY be
used for shadowing the bios, video etc., and is unusable otherwise.

Has anybody ever heard of this?  Will this present a problem when 
attempting to load TSRs HI (with qemm.sys and DesqView).  Will OS/2
be a problem?

I would appreciate any information on this issue.

David Boyer
boyer@iuvax.cs.indiana.edu

kize@cup.portal.com (Brian L Kaisner) (02/20/90)

>I am looking at a 386-25Mhz motherboard with an AMI bios.
>The Documentation states that the area from 640K to 1Meg can ONLY be
>used for shadowing the bios, video etc., and is unusable otherwise.
>
>Has anybody ever heard of this?  Will this present a problem when
>attempting to load TSRs HI (with qemm.sys and DesqView).  Will OS/2
>be a problem?

The information here is rather sketchy, but I don't think you'll have any 
problems as long as the RAM _is_ there and accessible.  That fact that
shadowing is supported suggests that it is.

OS/2 doesn't use the BIOS or chipset memory mapping functions.  QEMM 5.0
can generally use convert any part of the memory map that isn't being
used by something else (video BIOS, etc) into useable high memory. In
fact, it figures out which portions of the BIOS ROM are blank/unused
and maps those to RAM.

>David Boyer
>boyer@iuvax.cs.indiana.edu

- Brian
  kize@cup.portal.com