From: Marko Mäkelä (msmakela_at_gmail.com)
Date: 2007-03-27 11:57:39
On Tue, Mar 27, 2007 at 11:29:12AM +0200, Anders Carlsson wrote:
> I looked around on the Internet and found some more motherboard pictures,
> but none that resembles this one. I assume the TED chip really is supposed
> to be there, so it is not just a random chip someone once upon a time has
> placed there...
You could try to draw a partial schematic diagram by tracing the circuit
board around the TED chip. Look for the power supply lines (test with
an ohm meter) and the data and address bus. The bus should be attached
to the processor and to memory chips, or bus latches or multiplexers.
The address bus of DRAM chips is multiplexed. Also some processors have
a multiplexed bus.
The location of the power supply lines can be a good test, because as
far as I remember, Commodore video chips have the power supply lines in
non-standard location (not in the corners like 74xx chips).
Marko
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