The designers of ARM used 6502 before and one of designers admits there was some inspiration from that:
https://people.cs.clemson.edu/~mark/admired_designs.html#wil...
"I learned about pipelines from it (by comparison with the 6800) and its designers were clear believers in the KISS principle. Plus the syntax of its assembler and general accessibility of it from the machine code perspective. I can still write in hex for it - things like A9 (LDA #) are tattoed on the inside of my skull. The assembly language syntax (but obviously not the mnemonics or the way you write code) and general feel of things are inspirations for ARM's assembly language and also for FirePath's. I'd hesitate to say that the actual design of the 6502 inspired anything in particular - both ARM and FirePath come from that mysterious ideas pool which we can't really define (its hard to believe that ARM was designed just from using the 6502, 16032 and reading the original Berkeley RISC I paper - ARM seems to have not much in common with any of them!)."
The CoCo3 had a memory management unit similar to the PDP-11 minicomputers which could do very coarse paging. I ran an operating system called OS/9 which was a minaturized Unix, I had a few UARTS and two terminals plugged in: a TRS-80 Model 100 and an old Dec Correspondent printing terminal.
There are many "paths not taken" in the computer industry, but surely Radio Shack thought about a Coco 4 which could go up against the Amiga -- the 68k had the dirty secret that it didn't perform better than upgraded versions of the 6502, 6809, Z80, etc.
The Apple ][gs was a similar dead-end. Steve Jobs underestimated the lifespan of the Apple ][, so he rushed to make the non-compatible Apple ///, the expensive Lisa, the underpowered first Macintosh.
In the meantime Apple ][ had a durable lead and Apple kept upgrading it in little ways.
https://en.wikipedia.org/wiki/Apple_IIGS
It had an underclocked
https://en.wikipedia.org/wiki/WDC_65C816
which could address 24-bit extended memory, just like a System/360 of old (way bigger than the PDP-11.)
It was underclocked because an unhobbled Applie ][gs would outperform a much more expensive Mac 2.
Apple stagged through multiple near-death experiences with the Mac. What if Apple had kept the ][ line going and built on the momentum that the ][ had? Today we might be running a 64-bit derivative of the 6502!