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Re: [midatlanticretro] Re: OT: Too quiet

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  • J. Alexander Jacocks
    ... Josh, The two primary failures that I know of are the power supply (every one that I have ever had has failed, at some point) and the PLA chip. Both are
    Message 1 of 31 , Oct 11, 2012
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      On Thu, Oct 11, 2012 at 1:45 PM, joshbensadon <no_reply@yahoogroups.com> wrote:
       

      --- In midatlanticretro@yahoogroups.com, "B. Degnan" <billdeg@...> wrote:
      >
      > I have been repairing Commodore 64's for the PC shop, and wrapping up my
      > Visual 1050 project. I have been trying to get CUTTER working again on my
      > IMSAI. THis weekend I am going to resume the PDP 11/40 project, and get
      > the 11/05 workspace ready.
      > bd

      What is "CUTTER"?

      Myself, I've been cleaning up my basement, bought a bunch of cheap shelves and finally started to put my computers out for display. Prior, they were mostly boxed up. There's no sense in leaving them boxed up, I prefer to have them displayed. I only wish I had a bigger basement! Talking about C64, I've misplaced my video cable in the clean up. Hopefully I have more than one and it will show up somewhere.

      Cheers,
      Josh

      PS. Are there any common failures to note about the C64?

      Josh,

      The two primary failures that I know of are the power supply (every one that I have ever had has failed, at some point) and the PLA chip.  Both are easily fixed, as there are a bunch of aftermarket PLA replacements available.  Individual Computers has a quality replacement PLA, for instance.

      - Alex
    • Bill Dromgoole
      ... Yes, In my opinion you are correct. In the early years of semiconductors most parts have three digit date codes. You have to know the approximate decade
      Message 31 of 31 , Oct 18, 2012
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        >
        > Here's a transistor with 430 on it. Would that make it 1964, week 30?
        > Transistor part number is 2N1218. Or does the 430 refer to the factory the
        > transistor was made? or other?
        >
        > Photo of transistor posted in the photos/Josh Bensadon folder of this group.
        >
        > I've seen some IC's with only a 3 digit code on them (not part of this analog
        > computer). Case in point is the following:
        >
        > CD4023BE
        > RCA H 650
        >
        > Is that to mean 1976 week 50?
        > H being the factory where it was made?
        >
        > Cheers,
        > Josh
        > ------------------------------------

        Yes, In my opinion you are correct.
        In the early years of semiconductors most parts have three digit date codes.
        You have to know the approximate decade the part was first produced to get the
        correct date.

        Sometimes you have trouble telling the part number apart from the date code.
        In the 1970s a lot of the 7400 series ic's had date codes like 7414 and a part
        number like 7404.
        I was always having trouble with those.

        A good history of early transitor marking can be found here.
        http://transistorhistory.50webs.com/index.html

        billdrom
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