From: tictac@wam.umd.edu (Shake it to the Left)
Subject: Help w/SB and Memory Parity Problem
Organization: University of Maryland, College Park
Date: Mon, 25 Jan 1993 23:29:37 GMT

Recently I had posted on the network about problems I was having with
installing a Soundblaster in a 486DX/50 based machine (a Zenon VLB).
I want to thank those of you that responded, and I want to continue
my investigation into what underlies the problem with these questions.

When we left off, I was trying to install a regular SB 2.0 in my machine.
I tried using 1.0 and 2.0, same problems.  Test-sbc.exe freezes when
trying the FM portion, and Windows gets upset when I try and play .WAV
files, kicking me out and telling me on a blue screen that I have a
memory parity error.

This I see as two problems.

The FM voice problem is something which, by your messages, Creative
Labs seems to have acknowledged, but aside from that, where is
'the fix?'  I am waiting on getting a SB-Pro to see if that may
solve the problem, but I have gotten one message saying that even
the Pro has this problem, due possibly to the fact that the bus
speed runs circles around the SB.

The problem I am now concerned with is that blue screen.  I
want to make sure there is nothing wrong with my machine.

1) Is a .WAV file FM?  If so, it might explain the error, but
   then again, why did test-sbc.exe not kick me out as Windows
   did and say 'Memory Parity Error, System Halted'

2) Read the following clips from 'Memoirs of an Ultrasound Owner'
   This part/these parts were written by Etienne Mayrand
   (if you are reading this, I'd appreciate you sending me what
    you found out about your memory parity problems)

----Clips from Etienne's writing-------
----------------------
Troubleshooting

        At this point, I was pretty confident that everything was
fine. But this is not called the troubleshooting section for nothing.

        The next logical step was to try the demos. So, I typed
mididemo.bat to hear the MIDI demos. The screen went blank, then
nothing. Even the three finger salute was ignored. Grumble, reset. I
checked everything twice, but still no go. Then, I remembered that I
had set the bus frequency to a very high 16 Mhz. Maybe the soundcard
was not able to keep up. I lowered the frequency to 4 Mhz (better be
safe), launched the demos for the nth time and got... ON BOARD MEMORY
PARITY ERROR, SYSTEM HALTED. Oh no...

        Finally, after two wrenching hours of uncertainty and doubt
(is the card defective,...is the computer defective...,why me...), I
discovered a CMOS option that allowed me to disable memory parity
checking.  It worked!! Later, I learned that I could get rid of the
problem by changing the card setting from DMA channel 7 (16 bits) to
DMA channel 3 (8 bits) without any loss in performance. Most computers
have no problems, but I am the unlucky owner of one which does have a
problem. So, for those who encounter the same glitch, either change
the DMA channel used by the card, or disable parity checking.

Windows 3.1 compatibility

        The UltraSound is Windows 3.1 compatible. At first, I had a
problem with parity checking (again!). This time, each time I tried to
launch Windows, it crashed with a "memory parity error". Since I
thought I had solved that problem earlier by disabling parity checking
in hardware, I didn't know what to do. Finally, I decided to remove
any trace of the UltraSound driver from Windows and start over with a
clean slate. As I was browsing the SYSTEM.INI configuration file,
angrily deleting every reference to the UltraSound driver, I saw this
line:

device=*parity

        I commented it by adding a semi-colon at the beginning of the
line, like this:

;device=*parity

        Then, I installed the UltraSound driver and restarted Windows.
It worked! No more parity errors! (champaign, anyone?).

        To my knowledge, I am the only one who had this problem. It
may be my memory chips, or a bug, or some mysterious conflict in
memory. In case someone else has a similar problem, here's the
recommended procedure for the installation of the UltraSound Windows
3.1 driver:
-----------------------------end of clip----------------------------

Etienne, if you read this, please let me know what you found out about
your mysterious problem.  For those of you patient enough to bear along
with this message, have you seen this problem before?  (Memory Parity
Error?)  What causes it?  What can solve it?

Concerned about more than the soundcard now,
A. Almeida
tictac@wam.umd.edu
<please send replies directly to me, if anyone is curious about
 my findings, mail me and I will let you know>
Newsgroups: comp.sys.ibm.pc.hardware