[bryanlarsen]

If the 65816 (or something very similar to it) was available in 1978, the computing world would probably be very different now. 1978 was the year that both the 8086 and 6809 were released, which were similar 8/16 bit chips. 1979 saw the release of the 68000, which was a much more powerful chip than 1983's 65c816.

[cmrdporcupine]

68000 was more powerful for addressing large amounts of RAM that nobody could afford. In terms of actual workhorse performance there's a good argument to be made that a similarly clocked 65816 could outperform a 68000, unless your benchmark is heavy on 32-bit integer calculations. Instructions per cycle and interrupt responsiveness are higher for the 65xx (and 6809)

I'd prefer a 6809 with a wider address bus over a 68000. I wish Motorola had improved on the 6809 rather than having two competing architectures. The 6809 is a joy to code for.