You have forgotten the DEC Rainbow. But that's ok, everyone else has also forgoten the Rainbow.
Which is sad really. It was a dual-processor system - a Zilog Z80 and an Intel 8080 CPU. When it ran CP/M the Z80 did everything, but when it ran MS-DOS the 8080 was the primary CPU and the Z80 handled the IO.
The architecture was even better thought through and didn't break up the RAM like the IBM PC did (hence the 640K "limit"). I remember booting my Rainbow 100B and getting 720KB of usable RAM without trying very hard.
Sadly, the only real games that got ported to it were the Zork line of Infocom games, and a few DEC written graphical games. (Anyone remember "SCRAM"? Probably not the most marketable game since the objective was to descend to the lowest level of a failing nuclear reactor and "scram it" to keep it from going critical...)
Ken, you have no idea how much your "little company" got me started in computers. Thank you!
Dan