lev@suned1.Nswses.Navy.MIL (Lloyd E Vancil) (01/05/91)
I was just reading of a math co processor bug that could explain why
some of us have problems with WINDOWs 3...
Apparently there is a timing error associated with a POPAD command in
some? 387 chips. I was reading in comp.binares.ibm.pc and someone has
come up with a program that checks for this problem. It seems that MOST of the
machines tested failed. Since this command is used to push/pop all 32 bit
registers, it occurs to some this could be the problem with Windows in certain
386 machines. Could a similar problem be the reason for occasional
"Unrecoverable..." errors in 286 machines?
I guess one question we could ask is;
How many out there with unexplainable windows problems are running
387 equipped 386 machines?
L.
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My employer has no opinions. These are mine!ZUR058@DMSWWU1C.BITNET (Ulrich Hund) (01/08/91)
Hi, I do *not* have a 387, but I have some WIN 3 Problems when running in 386 Enh. Mode. Paintbrush crashes 95% if I use a 30cmx20cm bitmap with an UNRECOVERABLE APPLICATION FAILURE. How to do it? Follow the following steps: 1) start Paintbrush (while in 386 E-M) 2) set bitmap size to 30cmx20cm 3) choose NEW from the FILE-menu 4) use the right scrollbar to scroll down entirely 5) if you reach the end of the picture, everything's ok. I use an DTK 386-25 64K Cache Clone with Hercules graphics and 4MByte RAM Anyone who has the same Problem??? Ulli
otto@tukki.jyu.fi (Otto J. Makela) (01/08/91)
In article <6897@suned1.Nswses.Navy.MIL> lev@suned1.Nswses.Navy.MIL (Lloyd E Vancil) writes:
[...] Apparently there is a timing error associated with a POPAD command in
some? 387 chips. I was reading in comp.binares.ibm.pc and someone has
come up with a program that checks for this problem. It seems that MOST
of the machines tested failed. Since this command is used to push/pop all
32 bit registers, it occurs to some this could be the problem with Windows
in certain 386 machines.
This is incorrect. The bug (which was found by Jeff Prothero) comes up when
the following instructions are executed on the 386 (from John Lauro's test
program which was recently posted on comp.binaries.ibm.pc):
mov eax,12345678
mov edx, 0
mov edi, 0
pushad
popad
mov ecx, [edx+edi]
If now eax ISN'T 12345678 any more, your 386DX or 386SX is faulty. I'd be
interested in knowing which chip revisions do this and which don't. I've
seen reports of both types for both chip types, for example I have a new
386SX machine at work which does NOT have this problem.
Could a similar problem be the reason for occasional "Unrecoverable..."
errors in 286 machines?
No. The chip is different, with it's own bugs.
For example, 286 doesn't have 32 bit registers, nor pushad/popad instructions !
I guess one question we could ask is;
How many out there with unexplainable windows problems are running
387 equipped 386 machines?
This problem doesn't have anything to do with 387s per se.
(followups directed to comp.sys.ibm.pc.hardware)
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