Re: Red Baron & Mathbox?

-----Original Message-----
From: "Kev" <mowerman@erols.com>
To: <vectorlist@synthcom.com>
Date: Mon, 30 Oct 2000 12:33:27 -0500
Subject: VECTOR: Red Baron & Mathbox?

> Okay,
>
> Me & Red Baron are duking it out again.
>
> I did a ROM checksum & this info may be handy....
>
> 3000-37FF = B/C3 = $4C27
> 3800-3FFF = A3 = $FD11
>
> 4800-4FFF = *1 = $65BF
> 5000-57FF = E1 = $6EA1
> 5800-5FFF = *2 = $24D9
> 6000-67FF = J1 = $4BBB
> 6800-6FFF = K1 = $576F
> 7000-77FF = L/M1 = $0FFD
> 7800-7FFF = N1 = $39B1
>
>
> The 2532 EPROM appears at *1 & *2, you need to add the checksums together to
> get the chip checksum.
>
> Anyhow,
>
> I'm doing the signature analysis of this. Step 1. I cannot get the proper
> signature from some of the bipolar PROMs, yet the input signatures are good,
> the PROMs verify good & I've used atleast 3 different PROMs with the same
> results. I can even remove the offending pin from the circuit & get the
> same wrong SA.
>
> I've changed the bit slicers too, same results.
>
> What should I be looking for now?
>
> Thanks,
> Kev
>
This may sound really stupid, and we are allways saying it - but did you replace the chip-sockets?

L8r.

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Received on Mon Oct 30 15:57:27 2000