On 5/14/2016 9:59 PM, Jonathan Gevaryahu via vcf-midatlantic wrote:
The XOR patent was https://www.google.com/patents/US4197590
Has a priority date of January, 1976, so the Cromeco Dazzler (1976) was released (probably) after the patent's priority date documents were filed. Hence using it as prior art in the commodore case would not have helped, unless there is notarized documentation showing it was working in late 1975...

That's a good observation.  I wonder if there is prior art on XOR that C= didn't leverage.
(Assuming that the XOR thing really was that damaging to C=, which I'm not certain is the case)