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Re: Bill's workshop

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  • Douglas
    ... Nice write-up Jeff! I really wanted to be there for the PET work, thanks for detailing it here. I had my TRS-80 Model I keyboard about 1/3 off the circuit
    Message 1 of 6 , Oct 29, 2012
      --- In midatlanticretro@yahoogroups.com, "Jeffrey Brace" <ark72axow@...> wrote:
      > From: Evan Koblentz
      > Sent: Sunday, October 28, 2012 4:04 PM
      > > What I really want to know is who won the first-to-smoke award. Otherwise,
      > > my title from last time carries over. :)
      > I got there 11pm on Saturday, so unless something happened before I got
      > there, then the honor goes to Bill Degnan. He smoked his arm. Actually he
      > burned his arm on a soldering iron, so I don't know if that counts ;) Ian
      > and I joked that we should burn the Commodore logo into his arm as a badge
      > of honor ;)
      > Bill can fill you in on what went on before I got there. But...
      > Ian Primus fixed and cleaned his Zenith Terminal.
      > Bill and John worked on getting the teletype working with the Altair 8800.
      > It printed a "D" ! Everyone was in great anticipation of the "D" coming out
      > and there were great cheers. We are such geeks. :) They can give you more
      > details.
      > Doug worked on his TRS-80. I'm not sure if he got it completely working.
      > I'm not sure what others were working on, but we stayed up until 2am and
      > then Doug left. The rest of us went to sleep and woke up at 9am. I woke up a
      > bit later.
      > So I got out the MARCH PET. And Ian Primus got to work on it. I greatly
      > assisted him and learned from him. Bill provided documentation and two
      > parts. Ian got it to work ! The problem was with the monitor. Ian replaced
      > a 10k ohm resister that had burned out (that was the smell that Jeff Frady
      > smelled many moons ago) and the monitor pretty much worked after replacing
      > the resistor. But the video was still jumpy, so he replaced a 1 micro Farad
      > capacitor that looked a little worn. But the monitor was still jumpy. After
      > some switching around a know good monitor and board (provided by me), we
      > realized that the monitor or its board inside the monitor was not the
      > problem. One minute the video was stable and the next (after checking to
      > make sure there was a secure connection) the video was jump again. I noticed
      > after this happened three or four times and pointed it out to Ian. So he
      > realized what was wrong. It was the soldering of the video connector on the
      > motherboard. Specifically the video monitor's connection to motherboard. It
      > needed some extra solder to make a good connection. Ian also soldered up
      > some other places that looked like it needed it. So it's pretty much working
      > and we had time to test the cassette drive. But were not able to fix in
      > time. We also noticed that some keys on the keyboard didn't quite work. So I
      > will look into cleaning it, would should be doable for me with some time.
      > Another thing was Bill Degnan was going to try to use his PETvet to diagnose
      > what was wrong with my PET. He was hesitant because, after using in *his*
      > PET, it stopped working. Ian noticed how the 6502 easily came out of it. Ian
      > noticed that the pins on the PET VET were too big and stretched out the
      > socket on the mother board. So the original 6502 didn't have a good
      > connection in the socket. So Ian was able to replace the socket and thereby
      > fix Bills PET. Ian can explain the exact technical terms. So if anyone is
      > going to get a PETvet, beware and take precautions. I will have to
      > investigate further to see if anyone else has had these problems. I will try
      > to contact the guy who did the VCF exhibit with the PET VET. For anyone that
      > doesn't know the PETvet is a RAM and ROM replacement board for the Commodore
      > PET, and potentially other 6502 based microcomputers. The PETvet connects to
      > the 6502 socket in your PET, and allows you to select your boot ROM via
      > jumper settings. It also allows you to view the memory of a running PET
      > using the replacement RAM by halting the CPU and sending the memory contents
      > over a serial port. This web site has more info:
      > http://www.bitfixer.com/bf/petvet.
      > We wrapped it up and left around 5pm.
      > Thanks to Bill Degnan for hosting ! It is very generous and hospitable. I
      > think that everyone sometimes just needs the right environment to be
      > productive in fixing computers (free from other distractions). When we are
      > at our own home, then we get distracted by day to day things. An environment
      > like this allows everyone to focus on one thing.
      > I look forward to researching more about the PET and going to the next
      > workshop. It gave me an understanding and a basis to start with my research
      > about PETs and other aspects.
      > Jeff Brace

      Nice write-up Jeff! I really wanted to be there for the PET
      work, thanks for detailing it here.

      I had my TRS-80 Model I keyboard about 1/3 off the circuit board
      while there before we bailed Sat night/Sun morning.
      (But not before busting Bills "wedding china" coffee mug ARGH)

      Got it all removed last night! 18 inches of solder wick later
      and painstakingly careful prying.
      Now I can get at each individual switch. Hard but worth it.

      Researching switches now some TRS-80 site folks are helping me
      find other keyboards w/ the same switches that might be far less
      beat. Or I can refurb these.
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