[kjs3]

I think it was Cromenco that had a setup where you had a 'master' S-100 CP/M CPU board that managed mass storage, printers and other things, and 'subordinate' S-100 cards that had CPU, memory and SIO. Each user would be dedicated a sub card and terminal, running their own full version of CP/M, and the master mediated access to shared resources. Very popular in small office settings for a while.

[guestbest]

That really sounds like a 8-bit mainframe with added steps.

[kjs3]

I'd say more like a VM system where there's a (mostly) 1-to-1 mapping between hardware and user, supported by a really simpleminded hypervisor. But I definitely see where you're thinking.