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Bill's workshop

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  • Evan Koblentz
    What I really want to know is who won the first-to-smoke award. Otherwise, my title from last time carries over. :)
    Message 1 of 6 , Oct 28, 2012
      What I really want to know is who won the first-to-smoke award. Otherwise, my title from last time carries over. :)
    • Jeffrey Brace
      From: Evan Koblentz Sent: Sunday, October 28, 2012 4:04 PM ... I got there 11pm on Saturday, so unless something happened before I got there, then the honor
      Message 2 of 6 , Oct 28, 2012
        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
      • Evan Koblentz
        Message 3 of 6 , Oct 28, 2012
          >>> 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 ;)

          Flesh d'Degnan!

          >>> 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"! ... Doug worked on his TRS-80.

          Glad to hear about all the progress. We'll have another tech weekend in the springtime, at the museum.

          >>>. 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!

          Excellent!

          >>> The problem was with the monitor.

          I told you so!

          >>> 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 known 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.

          Interesting -- Ian showed me the same fix for MARCH's Apple II a couple of years ago. One of our //c systems also has flaky video and I've been meaning to check the connector for that.

          >>> 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 ... should be doable for me with some time.

          Good news.

          >>> Thanks to Bill Degnan for hosting! It is very generous and hospitable.

          +1.

          In other news, the museum tour for Rutgers compsci students went well this morning. Last year the prof brought five students. This year he brought ten. They stayed for 90 minutes.
        • Mike Loewen
          ... That was also a problem with TRS-80 Models III and 4. Specifically, the power connections soldered to the video monitor. Mike Loewen
          Message 4 of 6 , Oct 28, 2012
            On Mon, 29 Oct 2012, Evan Koblentz wrote:

            >>>> 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 known 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.
            >
            > Interesting -- Ian showed me the same fix for MARCH's Apple II a couple of years ago. One of our //c systems also has flaky video and I've been meaning to check the connector for that.

            That was also a problem with TRS-80 Models III and 4. Specifically,
            the power connections soldered to the video monitor.


            Mike Loewen mloewen@...
            Old Technology http://sturgeon.css.psu.edu/~mloewen/Oldtech/
          • B Degnan
            I won first to smoke...no computers went up but I seriously singed my arm with a desoldering iron. -- Sent from my PDP 8/e.
            Message 5 of 6 , Oct 28, 2012
              I won first to smoke...no computers went up but I seriously singed my arm with a desoldering iron.
              --
              Sent from my PDP 8/e.
            • 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 6 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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