Elsewhere, Garth said:
GARTHWILSON wrote:
WDC is the intellectual property holder of the 65c02. The founder and president, Bill Mensch, created the 65c02 shortly after starting WDC. Rockwell was a second source, not the originator. The 65c02 is 100% WDC's baby, and not anyone else's. Bill Mensch is also a co-creator of the MOS6502 and the 6800.
(and also wikipedia presently names several companies as offering second-source 65c02 devices, in the wdc65c02 article which was previously the 65c02 article)
I wonder if this is the true state of affairs. No doubt WDC designed their particular 65c02, but how do we know, or why do we suspect, that the other company offerings are in any way derived from or licensed from WDC's design? They could as easily be independent re-implementations, especially from companies already licensed to produce NMOS 6502 designs, those licenses being from MOS or from Commodore. No doubt WDC would claim some intellectual property rights (they would of course have mask copyrights and copyright of their own netlists or source files) but I don't know if there's any obstacle to an independent implementation.
The datasheet at
http://www.datasheetcatalog.org/datashe ... 65SC02.pdf is for California Micro Devices' G65SC02, and on page 10 it lists some differences between this part and the NMOS 6502. Is that precisely the same set of variations that WDC parts have? I gather this part has TSB and TRB, but not RMB, SMB, BBR and BBS. Why would that be so if it were a second source, or built as a licensed design?
I'd be interested in any references!
Cheers
Ed
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