RE: 6502/6510 ROM selection daughterboard

From: Bil Herd <>
Date: Tue, 5 Jun 2012 07:57:23 -0400
Message-ID: <>
Does the community have the actual PLA terms as source for the various
devices or are they all/mostly reverse engineered?

-----Original Message-----
[] On Behalf Of Michal Pleban
Sent: Tuesday, June 05, 2012 2:45 AM
Subject: Re: 6502/6510 ROM selection daughterboard

Hello! wrote:

> I don't see this as a deal breaker type of problem. The same applies
> to ROMs. Yet people exchange them or replace with EPROM adapters, etc.

That's a good point. Well, if we decide to go this route, I don't see any
problems in doing this type of extension. I can do it, actually.

Plus, the character ROM replacement can then be done simply by un-socketing
the CHAR ROM chip, and placing a single wire from the CS# line to the CPU
extension board (assuming the CHAR ROM is socketed too).

> Could you maybe publish it? On zimmers for example?

Yes. I designed a PLA replacement circuit, and I intend to read and decode
every PLA that comes into my hands :-) I am missing only the 8296 now, plus
waiting for the 1551 to arrive from When I have all the stuff
ready, I will publish it.


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Received on 2012-06-05 12:00:05

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