Asteroids Deluxe AVG Help

I am trying to get my AD working again and I've come across what appears to
be an AVG problem. In test mode, the game board makes it through the ram
tests and resets during the all-is-ok beep. If I disable the watchdog, the
beep is a continuous tone. The test screen mostly displays, but there are
some random vectors. The DAC's seem to be good because the random vectors
are maintained within the DAC's range. Likewise, everything after the
DAC's seem good.

The reason I believe it to be the AVG and not the CPU comes from the
asteroids repair faq that Jess has linked from the AD page on gamearchive.
It doesn't say much in the way of troubleshooting the AVG though :(

A few interesting things that I have found while poking around are:

* There do not seem to be any stuck pins
* The display stays constant, so the AVG must be updating the same wrong
vectors
* Most objects that are drawn seem to fail in the middle of drawing them
* If I play the game blind, I can get a letter 'D' to move around the
screen like an asteroid
* All of the CPU logic seems to work fine

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Received on Wed Apr 19 03:22:17 2000