PDP-8 chase the lights

COURYHOUSE at aol.com COURYHOUSE at aol.com
Tue Feb 2 15:33:20 CST 2016


THAT IS  WHAT  WE  USED TO CALL THE  CYLON   EYE  PROGRAM!
eD#  _WWW.SMECC.ORG_ (http://www.SMECC.ORG)  
 
 
In a message dated 2/2/2016 1:27:02 P.M. US Mountain Standard Time,  
cctalk at snarc.net writes:

Our  group here in NJ + surroundings now has monthly-ish repair workshops 
(vs.  a few times per year before). At the workshop this past weekend, 
David  Gesswein continued restoring our PDP-8.

David summarized: "I fixed the  known fault of accumulator bit
going to zero when it was rotated left. This  was a bad diode on one
of the accumulator boards. I also replaced two bad  bulbs and a third
that died during the repair. Since one that died was one  I previously
replaced I'm going to use the not quite matching bulbs with  heavier
wires for future repairs. The wires are just too thinn on the 1762  bulbs
and now that they have aged they break too easy. I then found that  the 
teletype interface wasn't working and replaced a diode on a R220 to  fix 
output. Input is not working properly. I have traced it to a  particular 
flip flop on a R220 where when the data changes it feeds  through to the 
output without the clock active. I ran out of time to  identify the 
component that needs replacing."

Here's a little video  of the computer chasing its lights.  :)

http://www.vcfed.org/evan/pdp8lights.mp4



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