Re: Gravitar Weird Start up / hi score save

The EAROM uses a capacitor doubler circuit to produce something like
-28V for the EAROM. It runs off the -15V supply I belive. Im doing this
from memory so it may be +28V running off the +15V supply.

anyway, when the doubler caps dry out, the supply drops back down to
+/-15V and the EAROM won't work that way. There a diode as a part of the
doubler but I have never seen that go bad, just the electrolytics. Try
replacing both of those and I bet you will be good to go.

I guess first measure your voltage to see if it is low tho. :-)

good luck

Bob Langelius wrote:

> I just got Gravitar running in my Space Duel cab. At cold start it has
> weird letters and vectors. A power cycle fixes it.
>
> Also the Hi scores don't save after a power-down. I changed Earom -
> same situation. How does the earom work? Do they fail from age or use?
>
> Self test shows no failures.
>
> Thanks,
> Bob

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Received on Tue Sep 20 19:34:34 2005