Probleme find !!!

From: Douglas Little <dmlittle_at_compuserve.com>
Date: Sun, 26 Oct 1997 04:36:17 -0500

Hi,

> Doug and Jo was true: probleme was commi
> ng from Nemmesis boot freq !

;)

> I tried to switch off the nem by soldier
> ing the thin White and balck wire to the
> ground and then the AB was booting prop
> erly.

Good. All you have to do now is find out which
frequency is causing the problem - 20 or 24
MHz.

> So if someone knows the following of the
> operation (making the Nemesis Compatibl
> e with AB) it'll be great if he could te
> ll it to me tonight (we are saturday 9PM
> ) because I had to remove Motherbord fro
> m my tower and i would like to do as muc
> h thing as possible before fitting back
> the F030 in my tower !!!!

Here is something to try:

Reconnect the white wire to pin 5 of the IKBD
via a small resistor (about 470ohms -> 1k) and
keep the black wire soldered to the GND rail.

This will allow 16 or 20MHz only. The machine
will not be able to select 24MHz at all.

If that works, then you know it's 24MHz that is
causing the problem. You can either try to
mount a resistor on the black wire to pin 5 of
the MIDI chip, or you can mount a hardware
switch, or you could just leave it grounded.

The 20/40MHz mode is the only really useful
one on the AB anyway. The other one is too
fast for the processor and the Mach 210 chips.

I have seen this problem before, but it is very
rare. Most AB cards don't mind the short burst
of high frequency at boot time because the
card is running at 1/2 clocked speed and the
caches are off anyway. CPU problems only
occur when the caches are on because the
chip becomes more active in this state and
heats up a lot more.

> One more time: thanks to Doug and Jo..
> Hopping you'll watch your E-mails tonight

No problem. Good luck!

Doug.
Received on sø. okt. 26 1997 - 11:59:00 CET

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