Re: My rev-zero Apple II lives again!

[mjmahon@aol.com (Michael J. Mahon)]

Liam Busey asked:

>"Vince Briel" <vbrielnospamme@comcast.net> wrote
>
>-snip-
>
>> I discussed this issue with Rich and I have a 65C02 installed now on a II+
>> that I'm going to try the card on next week when I get it. Rich had
>problems
>> just getting a 65C02 to work in the II+ but I've got plenty of Rockwell
>> 65C02's that I've tested out with prodos.
>-snip-
>
>Do Rockwell 65c02's have the same instruction set as WDC 65c02's?

I'm assuming this is a casual question, and so I will answer
it casually, without opening the datasheets...

The Rockwell processors had bit set and bit reset instructions
which were very useful for embedded applications.  The WDC
processors did not include these.

Since Apple II's were produced with both kinds of processors,
software for Apples was written to the common subset.

-michael

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