VERSIONS AND VARIANTS
It all started with the 6500, created by MOS
Technologies, a company formed by ex-employees from Motorola, to be
similar to the 8-bit processor 6800, from
Motorola itself. The processor was so identical that it had to be
altered, originating the 6502. The 6502 was
different enough so Motorola attorneys couldn't bother MOS, and
similar enough so programmers that were used to the 6800 (as Stephen
Wozniak, see Apple II History) could use it. The greatest difference
was the price ($175 for the 6800, $25 for the 6502), as it was the
chosen one to equip the Apple II, a very successful computer of the
The popularity of the 6502 gave origin to a variety of other processors:
The 65C816S, or 65816, was the late answer to the 68000 family from Motorola, which was becoming a hit, equipping the new Apple Macintosh. It has 16-bit processor, and its program counter and bus were both 24-bit wide, allowing it to address up to 16MB -- the 80x86 bus was 20-bit wide, or 1MB. Besides that, it has a full 6502 compatibility mode. The 65816 was released only in 1986. If it was released before, would have been the natural option for the first Macs in 83, which could have been then compatible with the vast software library available for the Apple II. The Mac, from day one, wouldn't have suffered with its greatest enemy, the lack of applications, and would have guaranteed for itself the consolidated market from the Apple II. Perhaps the computer world would be different...
Eventually the 65816 was used in the the Apple IIgs, the discrete follow-up to the greatly successful Apple II series. Coincidently or not, it was also used by Nintendo in the follow-up of their most sucessful (and 6502-based) product. The Super NES, however, had a better commercial luck than the Apple IIgs.