360/50 microcode listing

[Jon Elson]

On 05/07/2015 01:56 PM, 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.
>
> - Rob
This is certainly not authoritative, but the best I've found 
so far :
http://www.ibmsystem3.nl/System360/index.html

Jon