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Thread: Lanier Model 103 "No Problem" word processor

  1. #161
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    Aug 2013
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    Larose, LA, USA
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    15087253171501064090024.jpg

    Beginning to build the schematic for the CPU card in KiCad.

    Slow progress because a lot of the chips aren't in the library.

    Phil

  2. #162

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    I have boot disks for the AlphaPlus 12, and 14. I have a complete Alphaplus 12. The Alphaplus 14 disks also boot the 7100. I also have boot disks for the 7200 and 7300. As well as CPU's.

  3. #163
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    Larose, LA, USA
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    I suppose the question there is would any of those boot this machine? Then, are you able to make copies, then are you willing to make copies?

    Phil

  4. #164
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    I decided last night to power up the Lanier. It's been off since, what, maybe some time in 2015. Took the lids off and pulled the PSU out, unhooked the machine from it, eyeing the old Sprague capacitors.
    IMG_20171110_162313.jpg
    Ran it up gently on the Variac, watching the voltages. Carried on bringing it up and everything was as stable as it ever was.. 5.04V, 12.00 being particularly stable and accurate still.

    Given that everything was present and correct, I reconnected and powered it up.

    20171110_173653.jpg

    Got the logic analyzer hooked in on what looked most likely to be the bus on the backplane. Lots of nonsense, coupled with the floppy drives going totally nuts.

    IMG_20171110_173951.jpg

    Tried to see what was going on. Removing the CPU and address decoder stops it from freaking out. It's random though. I'm thinking I might have to remove every chip and test. If I'm going to do that I'll socket them all.

    Would any of the 8080's support chips (or the 8080 itself) be damaged by being powered up without the +5V rail present? The psu had failed previously and the 5V rail was at zero.


    Phil
    Last edited by PhilipA; November 11th, 2017 at 08:09 AM.

  5. #165
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    Under instruction, here are the voltages present.

    20171114_200808.jpg

    -27 = -33.68
    +27 = +33.65
    +15 = +14.96
    -15 = -15.14
    +5 = +5.14
    +12 = +12.03
    -12 = -11.97

    No more than 0.006VAC ripple on any rail.

    TP1= +5.14
    TP2= +5.07
    TP3= +12.02
    TP4= +7.27
    TP5= +14.95
    TP6= +7.23
    TP7= +6.64
    TP8= -14.69

    Phil

  6. #166
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    Larose, LA, USA
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    Powered it up with everything plugged, and it went a bit weird.

    Lost the -12V rail.

    Pulled the video card, all voltages nominal. Lightning-bolt-question-mark LED lights up. (What does that one mean? Fault?)

    Pulled the RAM off, checked it for shorts, none found. Board still makes -12 rail collapse.

    -5 appears to be created by putting a diode and 330 ohm resistor from the -12 and shorting it to 0 with a Zener. I think the Zener had gone bad. Shall pull it out tomorrow, get the numbers off it and check.

    Phil

  7. #167
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    Yup, standard 500mA 5.1V Zener. With one leg pulled, all the RAM out it switches on and comes up (to completely blank screen of squares- expected), with a beep until the floppy drive clicks and the lights come on.

    I'll get a Zener, refit the RAM and see what it does.

    Phil

  8. #168
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    Larose, LA, USA
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    Well, that was masking another problem.

    The -15 rail (that the -12 is derived from) is hitting crowbar when it's loaded with all the cards. Next up is to find why. Power supply in bits again.

    Phil

  9. #169
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    Aha. Main smoothing capacitor for the -15 rail gone leaky. Soldered in a temporary replacement (15000uF 50V) on a couple flying leads and bingo. Stable voltages, with all the cards in and drives running. Tweaked to within 0.01V on all rails.

    Still does the click click clunk click thing occasionally. Periodically beeps. Not producing reliable results with each power-up.

    Derived -5V rails on video card at -4.89V and the CPU card at -4.96V.

    Phil

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