PDP-8 chase the lights

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