Delete comment from: Ken Shirriff's blog
| Two unique things about the 360/50 at UMR. It was supposedly the only
| non power of 2 system ever built up by IBM which could run as such.
| 1.5mb was not a standard for 360 memory sizes.
Nope. There were many of those. I had one that was 256KB (fast core) + 1MB (LCS). There were others I knew of (and just in NC), including 1.5MB (512KB regular + 1MB LCS). OS/360 NIP recognized these "odd" main core storage sizes and could figure out how much was "fast" and how much was "slow" (i.e., LCS). Unmodified, all the LCS core went into "Hierarchy 1" storage.
| IBM sold the system during the development of the 360/50
That would have been around 1965 (not 1969).
| and shipped a 360/40 to the campus in 1969 or 1970
By then, there were (I suspect) hundreds of 360/50 installations. It was a very popular machine (much more flexible than a /40).
| which was used for around a year
| till the /50 could be delivered to replace it.
It is much more likely that your 1969 or 1970 date is incorrect.
There were, in fact, "many" 360/40 machines shipped to customers who wanted larger ones (including 360/75s) to use temporarily until their box could be delivered. But all of those production problems were over by 1967 and everybody that wanted a /50 or /65 or /75 had them or could get them (with the usual sort of order lead time that was expected then).
I also used CPS, and loved it for some interesting research applications. It was actually much better than TSO in OS/360 Release 20.1 and 21.x. IMHO, TSO was essentially useless except for limited applications [and this does not include text or program editing) until the OS/VS2 1.6 and SPF era arrived.
Feb 1, 2020, 2:37:28 PM
Posted to Iconic consoles of the IBM System/360 mainframes, 55 years old