lots of panics in uPort V -> Problems @ 10MHz

[Denis Fortin]

In article <829 at ddsw1.UUCP> karl at ddsw1.UUCP (Karl Denninger) writes:
>In article <115 at hawkmoon.UUCP> det at hawkmoon.UUCP (Derek E. Terveer) writes:
>>[running SysV/386]  The problem is that
>>i seem to be having lots of (relatively) unexplainable panics and i was
>>wondering if anyone else with the 386 version was also having numbers of these
>>panics, like "kernel mode traps" (type e), "user mode traps" (type 2 and 8),
>>and "iupdat - iaddress >2^24" panics.  Plus i keep getting a number of "NMI in
>>system mode" messages.  
>
>The key one is the NMI message.
>
>This can only be generated one way -- if your memory board(s) generate a
>parity fault.

Hmmm.  I have been having similar problems, so I guess this is a good time
to post about them...

I'm running Microport System V/AT 2.3 on a 6/10MHz AT-class machine.

I can run the system with no problems at 6MHz, and I can run it at 10MHz
without any problems under both DOS and IBM XENIX 1.0 (which I don't use
anymore since I have uPort).  Unfortunately, whenever I attempt to run
SV/AT at 10MHz, it crashes after a few minutes (sometimes even before that).

In a few cases, I've noticed the message "NMI in system mode" at boot time,
*but* my 2MB of RAM are all 100ns chips, which *should* be more than 
sufficient for 10MHz operation!!!

(Question: my video board is an original IBM EGA board.  Could it be the
culprit?  Can it handle 10MHz?)

In general, the system will boot without any problems, and after a few
minutes, the response time slows down a lot and ultimately I get the
following message on the console:

	user=0xC7E
	cs=0x208 ds=0x220 es=0x220 ss=0x213 di=0x400 si=0x5BE0
	bp=0x2C0 bx=0x7 dx=0xA1 cx=0x0 ax=0x7 ip=0x5807 flags=0x202
	trap type 0xD
	err=0x210
	stack frame address = E830270
	Double panic: Software detects double fault

I have also seen "user=0x10 ... err=0x8173".

I know that this is a bit cryptic, but none of my requests for help from 
Microport on this issue (even when my SysV/AT was still under warranty) 
have yielded any result.  (In most cases, I was told that the info was
transfered to someone else ... who never got back to me.)

I currently have an update contract (I still think that uPort is a pretty
good product), but I have not purchased a technical support contract because
from what I have seen during my warranty period, their technical service
won't help me much with this problem (note: this was about 1.5 years ago).

I guess my biggest problem is that I have really no way of knowing what
the register dump really means...  Also, I'm very puzzled by the fact
that IBM Xenix 1.0 will run on my machine at 10MHz (I can understand why
DOS works: it's not as demanding interrupt-wise on the machine, but XENIX
*does* work and that annoys me!)

Anyway, if anybody has an idea about things I could try, I would appreciate
it *** A LOT ***.  Running my AT at 6MHz is definitely not the same as
running it at 10HMz (SIGH!).

(Also, could anybody post a description of what those "user=n" messages
 mean?  It's not anywhere in the documentation.  (I understand that you
 get vanilla-flavored SysV documentation, but I still feel that it's
 quite annoying to run software that generates hexadecimal error messages
 with no explanations!))
-- 
Denis Fortin                            | fortin at zap.UUCP
CAE Electronics Ltd                     | philabs!micomvax!zap!fortin
The opinions expressed above are my own | fortin%zap.uucp at uunet.uu.net