@ psxphill
I'm no lawyer but I think if even a small amount of code used for the Pet got into the C64 then 1977 is right. I'm sure we'll have our 'in house' law experts chime in on this soon enough:rtfm:
If you read the article, commodore got a refresh of BASIC from Microsoft in 1979. So the code for the C64 should have come from there.
The copyright on software is complicated though. Copying an entire rom is probably covered by copyright in the 1970's (I'm not a laywer, I'm especially not a time travelling lawyer), but even today you can't copyright individual instruction sequences. By only asserting the 1977 copyright, they are creating an evidence trail that means their copyright runs out 2 years earlier than it should. Commodore (if they were around) might claim that the 1991 copyright would cover all the ROMS in the c65, but I believe if they tested that out in court they would lose.
Copyright itself is complicated. Steam Boat Willy seems to be in a quantum state of protected by copyright laws and also in the public domain.
Back in the 1980's I remember people saying they didn't buy a c64 because they wanted a computer with Microsoft basic. It seems the rebranding may have cost some sales.
