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24008Re: [midatlanticretro] Fun with the Altair 8800

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  • B Degnan
    Jan 8, 2012
      I have trouble with my DaJEN board in the Altair. I can get to the
      prompt but nothing else.

      At 10:57 AM 1/8/2012, you wrote:
      >--- On Sun, 1/8/12, B Degnan <billdeg@...> wrote:
      > > Awesome. I am
      > > working with Herb to put that set of code on a 1702 prom to
      > > test hos PROLOGUE programmer.
      >We burned the code into a 2708 with John's Dajen SCI board plugged
      >into the Altair. Now I can swap the RAM out for a Morrow Switchboard
      >with the the ROM mapped and run it directly.
      >Speaking of which, the Switchboard I have is a *very* early one,
      >with no solder mask, and is labeled as Thinker Toys, with a
      >copyright date of 1978. There were a lot of very bad modifications
      >around the comparators that read the switches, and I've been trying
      >to fix it... but it doesn't match the schematics for the common
      >Switchboard - John also has a Rev 2 Switchboard, the common blue
      >one, and it's rather different. This early one seems to have a
      >different switch layout and some other changes in the way it
      >addresses the I/O. Does anyone have the docs for this? At the moment
      >the only way I can get the ROM enabled is with some jumper wires to
      >force it so, with the rest of the board effectively disabled.
      >Yahoo! Groups Links
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