On 07/18/2015 09:06 PM, Mike Stein wrote:
I always wondered which was more efficient, multiplexing among essentially complete 'computers per user' sharing a common I/O 'channel' or swapping processes and memory banks...
Well, the multiplexing (via hardware) memory among a single processor did have the advantage that it was possible to hang a single "processor" without taking down the whole shebang--you could simply label the processor as unavailable in the processor pool. Believe me, when debugging PPU programs that was very handy--hang a PPU, try again, without rebooting the system.
Later versions of the Cyber (e.g. 170/180) actually used separate completely autonomous processors.
--Chuck