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Thread: 1000SX, TrackStar 128, and Capacitors

  1. #1
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    Default 1000SX, TrackStar 128, and Capacitors

    CAUTION! EXTREME IGNORANCE FOLLOWS! ;^)

    The Diamond Computer Systems TrackStar, mostly (?) sold at Radio Shack for installation in the Tandy 1000SX, put a single-board Apple II clone into a PC clone. Several upgrades were done.

    I have obtained several, mostly complete in the box, TrackStar 128s and have another incomplete out of the box unit. The 128 required installation of a capacitor on each of the TEAC floppy drives, otherwise Apple disks would not be correctly read (tested and proven). Installation instuctions for the latter TrackStar E don't include capacitor installation either.

    Installation instructions for Tandy 1000 SX computers (truncated):

    Installing Capacitors in the TEAC Disk Drives
    A. Installation in TEAC FD55BV-75-U Drives
    ...
    4. Turn the disk drives over and locate TES PINS 1-8 (TP 1-8 ).
    5. Connect the capacitors between TP4 and TP5 on both drives.
    ...
    B. Installation in TEAC55BV-6 Disk Drives
    ...
    4. Turn the disk drives over...
    5. Install the capacitors between TP5 and TP6
    ...
    C. Installation in TEAC FD-54B-02-U Drives
    ...
    4. Locate the TEST PINS (TP7 - 10, G). [?Scanning error?]
    5. Install the capacitors between TP7 and TP8 ).
    ...
    D. Installation in TEAC 55B Disk Drives
    ...
    3. Turn the disk drive over and locate the custom I.C. TEAC 7458-00. Just above the I.C. are the TEST PINS (TP1-8 ).
    4. Install the capacitors according to the following table:
    Drive # Test Pins
    FD 55b 01 LL 7 and 8
    FD 55BV221-V 4 and 5
    55BV - 06 -U 4 and 5

    Installation instructions for IBM PC computers don't mention the capacitors, and I have successfully used non-TEAC drives in my 1000SX, so apparently they are only needed on TEAC drives.

    I have one capacitor and would like to make up some more and need help on what to order.

    TEAC FD-55BR-521-U:



    Test Pins:



    Capacitor:




    I understand the 104 but what is "M5E"? What do I order for correct capacitors and what do I order for the "sleeves" that slip over the Test Pins which appear to be standard jumper pins spaced for a normal jumper.

    Am I missing anything? Recommendations on where to order from?

    TIA

    Mike

  2. #2
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    Default

    The M5E apparently denotes the tolerance and voltage rating of the capacitor. According to this page, the M denotes +/-20% tolerance, while 5E likely denotes voltage rating, though I have yet to find a definition for that particular suffix. In all likelihood, a 0.1F capacitor rated at 630V or so should cover your bases, but a part with the exact same markings can be found here (apparently a 50V part). As for the pin sleeves, they look rather like 'molex pins' as used for early IC sockets. Amazon, Mouser and other sources should have them in various sizes. Good luck!
    -Adam

  3. #3
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    Default

    Perfect! Thank you.

    Mike

  4. #4
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    Default

    Awesome! Thanks for the photos and information on the capacitors. I'll definitely be getting them and trying it out.

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