Battlezone repair question

I've noticed that my Battlezone never generates the RAM tones in self test.
The game seems to operate normally (for the time being!). I know that the
docs say that if "no tones are generated during self test, check chip Nn"
but I have a hard time believing that the game would otherwise function
correctly if this chip were bad. Has this happened to anyone? I haven't
yet setup my eprom programmer since I moved, otherwise I'd just program one
and be done with it. I'm just curious, that's all.

Anyone have a web page for some good procedures for debugging a BZ board? I
have two boardsets that I'd like to get working again and I was defeated the
last time I took up the effort about 3 years ago. I figure that maybe some
people have learned a great deal about this beast since then that might have
documented some really good methods for fixing this guy. The analog end of
things are quite straight forward since it is relatively simple to follow
the path of an analog signal. It's the digital side of things that gets
hairy. For instance, when the CPU has a clock, and all address and data
lines are pulsing, and each RAM chip is being selected at some point, as is
each ROM, and the watchdog is barking, what's a good place to start? The
watchdog is barking presumably because the CPU didn't write some data to the
appropriate memory location in order to reset the timer. But, why? Memory
access "appears" to be good. Anyway, it's this type of stuff that gets
hairy, for me. What have some of you done when you run into this sort of
road block? Replace all the RAM anyway? Then what?

On another topic, anyone have an estimate for the price to produce a 2 sided
PCB, same size as Battlezone's? Yes, I'm still thinking of laying out a PCB
and populating it with new components. Unless the price is ridiculously
expensive. It seems to me that making a new board would give reliability at
least as good as they were originally, and with better components of today,
the boards should run properly, longer - in theory. :-)

Thanks,
Joel-

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Received on Wed Jan 12 13:18:06 2000