[comp.sys.ibm.pc.misc] 386 memory problems - help needed

simon@hpspwr.enet.dec.com (Curiosier and curiosier...) (05/20/91)

I need help in solving a serious problem:

I replaced a 16 MHz 386SX board with a used 20 MHz 386DX, leaving all 
other hardware and software the same.  Both the previous SX and the 
new DX have AMI BIOS's, date at about the same time (March - June 89).  
The rest of the system:

4 MB RAM, 512K VGA, RLL disk controller, 240 MB Maxtor disk with 1224 
cylinders, partitioned with SpeedStor.

Software:  QEMM 5.12 with Windows 3.0; 512K PC-CACHE (*NO* Smartdrv.sys!).

The 20 MHz board came from a known working PC, and did not have any problem.  
The other difference is that this board had an MFM controller while the 
new system has RLL.

Problem One:

The boot-up memory test counts to 4096.  The BIOS screen that comes
after this reports 640K plus 3072K extended.  The board has 4 1x1 SIPP 
modules.  Manifest also shows 3072K.  The previous board showed all 
3456K.  Where are remaining 384K? 

Problem Two:

Windows started to behave unpredictable.  It lets me open a few
non-Windows applications (sometime two, sometimes four, every time 
different), then, at an attempt to open another, the system 
goes to reset on its own.

I opened three non-Windows applications, reduced them to icons, then 
tried to restore and got a message:  "Insufficient memory, try to close 
one or more applications and try again" (or close to this).  An attempt 
to restore any application from an icon in order to close failed because 
all of them produced the same message!

I reboot the system, open Windows, run an application, close windows, 
and instead of returning to the DOS prompt, it resets the system.

Any help will be greatly appreciated.
---------
Leo Simon			simon@pwrvax.enet.dec.com

Who is not liberal when young, does not have a heart.
Who is not conservative when old, does not have a brain.

				-- Attributed to many

jerry@polygen.uucp (Jerry Shekhel) (05/22/91)

simon@hpspwr.enet.dec.com (Curiosier and curiosier...) writes:
>
>I need help in solving a serious problem:
>
>Software:  QEMM 5.12 with Windows 3.0; 512K PC-CACHE (*NO* Smartdrv.sys!).
>
>Problem One:
>
>The boot-up memory test counts to 4096.  The BIOS screen that comes
>after this reports 640K plus 3072K extended.  The board has 4 1x1 SIPP 
>modules.  Manifest also shows 3072K.  The previous board showed all 
>3456K.  Where are remaining 384K? 
>

Some motherboards (DX and SX) cannot relocate the 384KB RAM between
640KB and 1MB.  Some are even weirder -- my 386/33, for example, can
relocate different portions of the 384K depending on how much memory
I have installed.

>
>Problem Two:
>
>Windows started to behave unpredictable.  It lets me open a few
>non-Windows applications (sometime two, sometimes four, every time 
>different), then, at an attempt to open another, the system 
>goes to reset on its own.
>

I had similar problems when I first got the DX motherboard.  Make sure,
if you have RAM shadowing on, to force QEMM to exclude those regions 
between 640KB and 1MB that are covered by RAM shadowing.  This fixed
the problem for me.

Good luck.
--
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| JERRY J. SHEKHEL  | POLYGEN CORPORATION  | When I was young, I had to walk |
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