RE: Tracking down a voltage dependent chip

Well that didn't get me anywhere, still digging.

Any idea if these boards have a self test mode? Would help to have a stable
screen to debug.

Thanks,

David

From: owner-rasterlist@vectorlist.org
[mailto:owner-rasterlist@vectorlist.org] On Behalf Of Rodger Boots
Sent: Saturday, September 21, 2013 3:42 PM
To: rasterlist@vectorlist.org
Subject: Re: RASTER: Tracking down a voltage dependent chip

Bipolar (TTL (7400 series) and ECL and the old frame buffer RAM) speeds up
as it gets warmer. MOS (large RAM/ROM/EPROM) slows as it warms.

Everything gets faster with increased voltage.

So you can lower voltage until it starts acting up then either warm bipolar
or cool MOS a bit and note the effect.

Also, ECL was used in early Nintendo and it ran from a separate -5.1 (?)
supply, make sure to check that. It doesn't sound like an ECL problem,
though.

On Sep 21, 2013 5:24 PM, "David Shoemaker" <davids@oz.net> wrote:

I have a DK which if the voltage is low at all (like 4.95v) will start to
display graphic corruption (Kong gets stripes and princes hair starts to go
to the wrong place). Any suggestions on finding the chip involved? I have
done this before by piggybacking the ram / buffers around the sprite but in
this case I get no change.

Thanks,

David

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Received on Sun Sep 22 02:39:55 2013