Date   : Sat, 30 Oct 1999 10:59:31 +0200
From   : "Mark Usher" <marku@...>
Subject: Re: Further investigation 

> Now I'm confused.

Hmm, not half as much a I have been :-)
Right, found a bad joint on R61, resoldered, and things look a little
better.
Still no wave coming out of pin 12 IC94 though.

What I have discovered that removing the 8271 allows the machine to boot.
Replacing it, hangs the machine, as does setting jumper 9 with the 8271 in
place (disables disc inteface NMI).
Which leads me more towards the interrupt gen / ack side of things.

When booting and into NFS, a *I AM SYST leads to a Line Jammed error which
would be in accordance of the lack of wave from pin 12 IC94.

Anyway, I'll have a look at the circuit diagram a little more now and check
around IC97, IC01, IC27.

As always, if anyone thinks of anything....


Mark