>Sounds like maybe your "LETA" (Trackball Interface Custom IC) is maybe
>having thermal probs.
>There really isn't much else that it could be since the spinner goes
>directly into that IC and
>only has small noise caps to ground and some helper resistors between
>ground and +5V. I doubt that
>the CPU is having problems reading the LETA or else your game would most
>likely crash as well.
>Even tho they are custom IC's, they are used on Crystal Castle and I
>think Millipede boards.
>
I agree with Jess that it MAY be the custom part, I would not totaly
discount the possibility that it is the spinner's opto-interrupter.
>> Obvious cause: Bad board.
>> Unobvious fix: Sending the board to someone with a known working MH
>> setup results in the board and spinner behaving fine.
>>
>> Obvious cause: Bad spinner.
>> Unobvious fix: ...so why can I play Tempest normally?
>>
>> Obvious cause: Bad wiring.
>> Unobvious fix: Problem reproduced on two separate wiring harnesses.
>>
Doug, you didn't say if you tried a different spinner on the MH bd.
The spinner interface circuits on MH and Tempest are very different.
It's possible that the Tempest buffer circuits are more forgiving of
degraded opto current output. Only a scope or meter will tell.
Dave
Received on Mon Feb 8 13:08:12 1999
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