[comp.sys.ibm.pc.misc] Help! Where's the lost 128K memory?

TKUSTER@auvm.american.edu (Todd) (06/10/91)

In article <1991Jun8.201349.14697@bronze.ucs.indiana.edu>,
cwang@copper.ucs.indiana.edu (Ted Wang) says:
>
>Hello!  I have a 80386-25 based PC with 64K cached memory and 4MB RAM.
>It uses a noname motherboard and AMI BIOS.  When I turn on the
>computer, it does self memory testing and says 3968 OK instead of 4096
>OK.  I thought that this might because of the SIMMs, so I pulled out
>the SIMMs ( four 1MBx9 SIMMs) in my computer and plugged into my
>friend's computer and everything's fine (I mean he got 4096 OK message


I have a similar occurence but it isn't a problem.  64k goes towards
Bios Shadowing and 64k goes towards video shadowing.  This memory
doesn't appear during the memory test.  You should try going into
setup and see if you have these features.  If you want the full
4mb of RAM you may be able to disable the shadowing.

I hope this is your problem

Later...

kailun@cs.washington.edu (Kai-Lun Chan) (06/11/91)

In article <91161.105003TKUSTER@auvm.american.edu> you write:
>In article <1991Jun8.201349.14697@bronze.ucs.indiana.edu>,
>cwang@copper.ucs.indiana.edu (Ted Wang) says:
>>
>>Hello!  I have a 80386-25 based PC with 64K cached memory and 4MB RAM.
>>It uses a noname motherboard and AMI BIOS.  When I turn on the
>>computer, it does self memory testing and says 3968 OK instead of 4096
>>OK.  I thought that this might because of the SIMMs, so I pulled out
>>the SIMMs ( four 1MBx9 SIMMs) in my computer and plugged into my
>>friend's computer and everything's fine (I mean he got 4096 OK message
>
>
>I have a similar occurence but it isn't a problem.  64k goes towards
>Bios Shadowing and 64k goes towards video shadowing.  This memory
>doesn't appear during the memory test.  You should try going into
>setup and see if you have these features.  If you want the full
>4mb of RAM you may be able to disable the shadowing.
>
>I hope this is your problem
>
>Later...

I have a similar problem, too.  Even if I disable the shadowing, only
3712K (640 + 3072) appears during the memory test.  Does it mean that
the 384K cannot be used in any other way?

kailun

 

thoger@solan.unit.no (Terje Th|gersen) (06/12/91)

In article <1991Jun10.213213.5317@beaver.cs.washington.edu> kailun@cs.washington.edu (Kai-Lun Chan) writes:


     In article <91161.105003TKUSTER@auvm.american.edu> you write:
     >In article <1991Jun8.201349.14697@bronze.ucs.indiana.edu>,
     >cwang@copper.ucs.indiana.edu (Ted Wang) says:
     >>
     >>Hello!  I have a 80386-25 based PC with 64K cached memory and 4MB RAM.
     >>It uses a noname motherboard and AMI BIOS.  When I turn on the
     >>computer, it does self memory testing and says 3968 OK instead of 4096
     >>OK.  I thought that this might because of the SIMMs, so I pulled out
     >>the SIMMs ( four 1MBx9 SIMMs) in my computer and plugged into my
     >>friend's computer and everything's fine (I mean he got 4096 OK message
     >
     >
     >I have a similar occurence but it isn't a problem.  64k goes towards
     >Bios Shadowing and 64k goes towards video shadowing.  This memory
     >doesn't appear during the memory test.  You should try going into
     >setup and see if you have these features.  If you want the full
     >4mb of RAM you may be able to disable the shadowing.
     >
     >I hope this is your problem
     >
     >Later...

   I have a similar problem, too.  Even if I disable the shadowing, only
   3712K (640 + 3072) appears during the memory test.  Does it mean that
   the 384K cannot be used in any other way?

   kailun

It depends on your chipset and BIOS.  On my Intel chipset + AMI BIOS
386sx I can put the 'shadow' RAM back into the memory pool, but on a
differen 386sx here, with Phoenix BIOS and Chips chipset, this cannot
be done.

Regards,
  -Terje

--
____________________________________________________________________________
thoger@solan.unit.no       |                 Institute of Physical Chemistry
THOGER AT NORUNIT.BITNET   | Div. of Computer Assisted Instrumental Analysis
                           |               Norwegian Institute of Technology

lsh@polari.UUCP (Lee Hauser) (06/12/91)

In article <1991Jun10.213213.5317@beaver.cs.washington.edu> kailun@cs.washington.edu (Kai-Lun Chan) writes:
>I have a similar problem, too.  Even if I disable the shadowing, only
>3712K (640 + 3072) appears during the memory test.  Does it mean that
>the 384K cannot be used in any other way?

I'm not sure, but on the computers we use, 128k is reserved, whether you 
shadow or not.  This reserving of potentially shadowed memory can also be
turned off in setup.



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