Re: Nemesis

From: citadel <citadel_at_indigo.ie>
Date: Mon, 3 Aug 98 13:24:48 -0000

Hi Doug,

I've been waiting your kind offer of help..but in the
interim, a few points to consider...

Forgive the open letter format but it's possible some
of the others may be able to help finally sort me out
on my Falcon/Nemesis difficulties. After implementing
every suggestion received, here in no particular order,
are a few more observations I've made re: the situation.

1) First of all I'm beginning to believe I've got a
defective Nemesis.

2) A question that's been nagging at me for weeks is
why were the two caps removed from the most recent 25/50
design? Was there something inherantly unstable in this
configuration?

3) Nemesis is the common denominator..the machine only
crashes when it's on...and at either speed.

4) I believe the problem always exists with Nemesis
running at either accelerated speed. It would seem
that v2.06 of Cubase is more sensitive to some sort of
problem/glitch related to a Nemesis signal/voltage?

5) There are no fixed circumstances when it does crash
..except for running Cubase. Is there something special
Cubase is looking for from Nemesis that other programs
don't require ...or perhaps, are less sensitive too?

6) The crashes, when they do occur, are *very* hard.
The processor doesn't even have time to post a flag or
any "bombs". The picture just freezes mid scan with no
more mouse pointer movement allowed. It seems to be an
a core level, instantaneous thing...unlike other system
crashes...almost like something important switched off!

7) The buffer works satisfactorily all the time...at
least as far as I can tell..with with Nemesis on or off.
SCSI transfers appear to be okay as well...although I'm
not sure if reducing the signal level at pin 110 of U36
through added resistance required to get rid of the
Cubase audio noise is necessarily a good thing, though.

8) No one else I've spoken too has ever had this noise
problem in Cubase. The sensitivity of the resistance/
capacitance at pin 110 of U36 when attempting to tune
out the noise (using a variable pot) while Nemesis is
running at either speed has to be seen to be believed.
We're talking a matter of 10's of ohms difference. It
should not be that sensitive...in fact there should be
no noise at all! This suggests that Nemesis, once again
the common denominator, is the culprit.

9) I've re-installed Cubase three times, I even went
as far to "040" patch one copy in order to eliminate
that possibilty as well.

10) My connections are fine...grounds everywhere and
even a shielded cable for the DMA line. Last week I
thought this might have been the fix...it wasn't! It
probably helped..but not so's you'd notice.

11) Keeping the entire circuit cooler (with a small fan
directed on it may delay the eventual crash for some
reason. Also running in 2 colours (and yes, I know
this is required with Cubase) also seems to extend the
running time...but it will crash...always!

12) I believe there's an instataneous loss of some
signal/voltage that Cubase must have steady supply of
and that other programs are more tolerant of. I'm now
trying to get an old oscilloscope of mine working so I
can scope the various signals and see if there's noise
riding on one of them...or perhaps some intermittent
situation occuring. Noise, which I'm hearing, would
explain a lot. The system could interpret a burst of
noise as something wrong and in the case of Cubase
shut it down. You may recall I mentioned that there
is a momentary flicker sometimes when it crashes.
This always kils off Cubase.

In the meantime, I'll ask David Encill for another
Nemesis to try...your support on this request would be
appreciated. This has now been going on for months...
just way too long. I'd really like to start flying this
"super" bird? So far it's been a very costly dodo...
both in time and cold hard cash...mainly spent at Titan.

Regards,

Michael Anthony

Ps. I've made, as anyone who has installed a Nemesis
knows, some major mods to my Falcon. Going back is not
an option and going forward to my 040 would be inviting
disaster. This problem must first be sorted.


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Received on ma. aug. 03 1998 - 22:19:00 CEST