🚀 go-pugleaf

"Michael J Kingston" <mikeki...@cix.co.uk> wrote in message
news:memo.20010727094436.36989A@mikekingston.compulink.co.uk...
> In article <7HU77.9333$TM5.9...@typhoon.southeast.rr.com>,
> d.h...@computer.org (Daniel House) wrote:
>
> I recollect reading that the 9020 was, or at least started as a
> multiprocessor version of the S/360 Model 40. No doubt there were changes
> and additions to the instruction set. This would have been very easy, as
> the Model 40, and most of the 360 line at that time, had microprogram
> control. In the case of the model 40 (and 30, following the abandonment of
> another technology), the microprogram was stored in a transformer
> read-only memory whose physical design (at least) allowed easy changes.
>
> It would be interesting to learn what changes other than the mechanics of
> shared memory were made.
>
> Mike Kingston

According to the IBM System Journal, Vol.6, No.2, Figure 1, p.82, the 9020
complex had 3 "computing elements," 3 "IO control elements," and lots (9) of
shared storage elements.  There is discussion in the text of flexibility in
configuration (and dynamic reconfiguration--required by FAA availability
goals).  The Journal discusses a shared configuration register used to
inform each element of its status in the configuration.  Other changes
discussed include a different set of PSW bits and IO addressing.

>From the only pictures I have seen, the control panel for a computing
element looks amazingly like the operator control panel of a System 360
Model 65. The 9020 control panel for an IO control element looks, again
amazingly, like the operator control panel from a System 360 Model 50. The
Journal doesn't mention these amazing similarities, nor did I see mention of
specific 360 models.