[email protected] (Tom Marchant) writes:
> And they ran on processors with somewhat different architectures. The s/360 
> model 67 supported 32-bit addressing, while s/370 was limited to 24-bit 
> addressing 
> until XA in 1982 or 1983 began to support 31-bit addressing, not 32-bit like 
> the 
> model 67.

360/67 multiprocessor support also allowed all processors to address all
channels ... the 360/65 multiprocessor support just shared memory but
had dedicated channels for each processor ... real multiprocessor
support was simulated by using twin-tail controllers with dedicated
channels from different processors to the twin-tails. this is also the
multiprocessor implementation for 370.

XA finally got all processors being able to address all channels.

-- 
virtualization experience starting Jan1968, online at home since Mar1970

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