360/50 microcode listing

Jon Elson elson at pico-systems.com
Thu May 7 21:11:36 CDT 2015

On 05/07/2015 02:15 PM, Chuck Guzis wrote:
> On 05/07/2015 11:56 AM, Robert Ferguson wrote:
>> Is there a reliable estimate of the number of extant 
>> relatively complete and/or actually working System/360 
>> machines? A registry, perhaps?
>> I would find that to be a very interesting data point.
> I'd be interested also, in that a simple 360 CPU is 
> essentially useless.  You need at least a minimum 
> collection of working peripherals to be able to do 
> anything at all.
> --Chuck
Small 360's at least had integrated channels, but you still 
needed control units AS WELL as the peripherals.
It ends up being a fair number of boxes to just get even a 
360/30 to do any reasonable bit of work.  Some of the unit 
record control units could live in shared boxes.  But, a 
reasonable system would need a unit record controller, a 
tape controller and a disk controller, as well as the card 
machine, tape drives and disk drives.

The 360/65 had no integrated channels, IIRC, so you needed 
to have at least a couple channel boxes in addition to the 
CPU and control units.  Ended up being a forest of blue 
boxes.  And, the wiring under the floor was totally 


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