MODCOMP II Revisited...

Lyle Bickley lbickley at
Tue Jul 10 17:11:21 CDT 2007

On Tuesday 10 July 2007 14:03, Chuck Guzis wrote:
> On 10 Jul 2007 at 12:04, Lyle Bickley wrote:
> >> So armed with a logic analyzer and scope, I began to debug the
> MODCOMP - one
> > chip at a time. After finding 20 or 30 bugs - ALL of which were TI chips
> > - I finally "relented".
> >
> > I have now replaced about one hundred and fifty TI chips in the Modcomp's
> > CPU and memory planes. I'm about 3/4 of the way through the process - and
> > the MODCOMP is becoming very reliable. It will run basic memory
> > diagnostics by the hour without failure.
> Why not simply re-tin the pins on the TI chips?  Shouldn't be too bad

The chips are mechanically very fragile. I'd rather replace them than rely on 
solder to keep them together ;-)

Also, since so many have pins break off when they are removed from their 
sockets, it wouldn't be a worthwhile exercise...


Lyle Bickley
Bickley Consulting West Inc.
Mountain View, CA

"Black holes are where God is dividing by zero"

More information about the cctalk mailing list