Talk:IBM System/360 Model 67

From Wikipedia, the free encyclopedia

[edit] Plan

I am currently revising/creating a series of articles related to the early days of CP/CMS. This involves the various systems referenced by the family tree at the end of this article, plus entries on Cambridge Scientific Center, Lincoln Laboratory, Type-III product, etc. Kindly bear with me while I get the various pages in synch. (I was doing some of this work in a private sandbox, but thought it would be better to start putting out some text. I do intend to provide a good number of citations and references, plus do some systematic editing/wordsmithing, over the next few weeks. Obviously feel free to jump in and fix anything that needs attention. Trevor Hanson 22:04, 19 October 2006 (UTC)

[edit] How many were made

I may be confusing the model, but is it possible only four were made, and the machine was announced only as a competitive strategy to break another company (perhaps Burroughs). IBM never plannned on it being a production machine, just a give away for universities. --ArmadilloFromHell 22:12, 19 October 2006 (UTC)

No, sorry, there were very many S/360-67s sold. Every CP/CMS site initially ran a S/360-67. National CSS had perhaps a dozen at one point. (IBM did take a lot of heat about the announcement of the S/360-67 and how long it took before they were shipped; and of coure the TSS/360 operating system was a washout, and this led to a lot of issues. But it was certainly a real system. I think CDC scrapped the most over the -67, but in the end Honeywell won Project MAC – the main sales effort the -67 was targeted to win.)

I'm not sure what other system you may be referring to. There were never many S/360-91, S/360-95, or S/360-195 systems; they were definitely real machines, but essentially research/experimental machines.

Can you provide any more details? We can try to track this down. I have Pugh's 800-page tome IBM's 360 and early 370 systems sitting at my desk here and I'm sure everything is there. Trevor Hanson 22:32, 19 October 2006 (UTC)

I probably have the wrong model number. My vague recollection is that for one model of 360 when announced, the machine did not even exist, the photograph was a fake mockup. It was announced in response to another company creating a new machine, and was intended to stop people buying that machine. The then had to scrample to create a real machine to avoid looking stupid. In the end they made only four and having achieved the marketing ploy, made no more. I think it was a machine designed more for "time-sharing" rather than batch processing. --ArmadilloFromHell 00:17, 20 October 2006 (UTC)

I have subsequently remembered more about this. In hindsight I should have figured it out right away. The "phony" system installed at only a few sites was the S/360-91. It was a real machine, but it was used in a phony way by IBM to compete against the CDC 6600. This led to a bitter legal battle which was eventually settled in 1973. There was a famous incident with a mocked-up front panel used for photos; I can't find it cited anywhere, but I remember hearing about it. The most well-known S/360-91 was probably the one at Columbia, which you can see here (http://www.columbia.edu/acis/history/36091.html) and which was a monster. There is some more about the antitrust situation here (IBM antitrust). IBM apparently lost something like $110M on the model, and there's a good argument that they didn't INTEND to use it in a phony way; their marketing rhetoric just got ahead of their delivery capability. Who knows? Trevor Hanson 00:36, 17 November 2006 (UTC)

[edit] Multiprocessor support

What were the features that provided better multiprocessor support? I vaguely remember reading about a feature of the Model 65 (and probably 67 as well) where references to the first N Kbytes of memory (for some value of N that I don't remember) would refer to different regions of physical memory on the different processors; were there any M67-specific features (other than ones needed only for systems with VM) for MP support? Guy Harris 21:54, 28 November 2006 (UTC)

Another good question. I will need to do some research. My update was based on the "blue letter" text, which claimed special MP capabilities for the -67 without going into detail. I have a 360-67 green card somewhere here; if I can find it I'll look for some MP-oriented instructions. I do see the following note in Pugh's book:

The first MP support for S/360 was an OS/360 extension called Attached Support Processor (ASP). Available in March 1967, it supported two processing units linked by a channel-to-channel adapter rather than by shared memory. The first...with shared memory was OS/MVT Model 65 Multiprocessing, available in March 1969.... LCS could not be attached in this configuration.

But I also just found this statement: "Planned for later release [in TSS] was software support for additional languages and for a multiprocessor version of the model 67 with up to four processing units." I'm not sure if this implies that the fourplex wasn't actually built. I seem to remember hearing about at least one, perhaps at FAA or NSA or something. NCSS might even have had one. I'll hunt around. In the meantime I'll reword the statement. Trevor Hanson 04:20, 29 November 2006 (UTC)