SWTPc 6800, common format (sharable?) repair journal?

From: Mike <dogas_at_leading.net>
Date: Sat Mar 20 22:24:56 1999

I have started restoring a swtpc 6800 and thought I'd ask for some comments
on restoration journaling. I've completed as detailed an initial inventory
as I can manage. I recorded the two busses on MP-B and some part numbers
that were disappearing from memory chips( 4x9 819 MM5257 ) on SSB M-16-R,
and transister( 18n9 ) from rectifier bridge. The soldering job on MP-A2
has alot of resin around connnections that I'm already pretty leary of. Ill
start off by digging for all the hardware documentationI can find...

First issue: Power system is missing the transformer. I do have the MP-P,
the filter cap, and the rectifier bridge.

I found a nice ad in Kilobaud issue #2 on the inside cover that gave values:
10amp, 25amp rectifier bridge, and 91000mfd computer grade filter cap. My
nighttime reading this evening shall be "Building Power Supplies", Archer,
cat 62-5025. ;)

First question: The baud lines on both busses (110,150,300,600,1200) caugt
my eye and that ad above states: "Crystal controlled oscillator( 1,7971 )
provides the clock signal for the processor (before?) and is divided down by
the MC14411 (both on MP-A2 GK) to provide the various baud rate outputs for
the interface circuts. Full buffering on all data and address busses..."
Does that mean that all these cards are serial?

Any switheads out there? Any thoughts on the forthcomming "This Old
Computer" episode? It would be cool to accumulate these restoration
reports and make some kind of open reference. I sure would find it usefull.
(read that as alot of things to repair. :)) I imagine alot of you have
encounters in repairland... It would be nice to have alot of this stuff in
a prolog predicate database for pattern searches.

- Mike: dogas_at_leading.net
"I am but an egg" -VMS
Received on Sat Mar 20 1999 - 22:24:56 GMT