Talk:IBM System/360

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LCM 360/20[edit]

As far as I know, the Living Computer Museum's 360/20 is not on display. Last I knew, the 360/30 was in its place, but not (yet) running. Gah4 (talk) 22:58, 21 May 2019 (UTC)

A S/360 M20 does not appear in any search of the LCM site (documents do but no hardware), there are not any S/360 listed in their on-line system status and there are not any S/360 listed in their Mainfram exhibit.
Rather than list a few survivors would we better off to just link the section IBM_System/360#Remaining_machines to World Inventory of remaining IBM System/360 & 370 CPU's.? Tom94022 (talk) 06:22, 22 May 2019 (UTC)


Most S/360 machines were leased, so went back to IBM. IBM had some tendency to make new things out of them. The 2319 disk drive system is made from recycled 2314s. Old 370/158s were used as channel directors for 303x machines, with channel only microcode. Outside the US, some were sold instead of leased, and that is mostly there they come from today. But otherwise, once IBM got leased machines back, they might have recycled the copper. Gah4 (talk) 06:14, 23 May 2019 (UTC)

Some comments:
  • Actually most s360s were short term rented rather than leased. A System/360 could be returned to IBM without penalty on 30 day notice. IBM's lease programs, FTP and ETP, are much more of the S/370 era and beyond.
  • Many 360's were purchased particularly by the leasing companies leading to one facet of the 1969 US v IBM antitrust suit. An owner then had dispose of them and in particular the leasing companies had very active re-lease programs. Some end-using owners sold their obsolescent 360s to leasing companies who then released them. But in the end when there was no demand for old iron even at greatly discounted prices the systems wound up salvaged for gold and copper and sometimes spare parts
  • IBM rarely made "new things" out of old hardware; the 2319 was a notorious anti-competitive reaction and AFAIK the only disk drive so made "new." In the 2319 case IBM had no new product to match the then superior PCM 2314's and couldn't stand the financial hit of a reduced the rental rate on its large installed base of 2314s so it came out with a "new" 2319 at a much lower lease rate calculated at a price to drive the PCMs out of business while locking in customers until the next generation disk drive came available.
  • Like a leasing company IBM tried to re-rent any off rent equipment and then when there was no longer any demand they salvaged it. The one thing IBM rarely if ever did was offer deep discounts on re-renting (e.g. 2314) prefering instead to rent (or lease) newer, next generation, equipment (i.e., the "new" 2319). The leasing companies by way of contrast offered very deep discounts for off lease equipment versus IBM rental rates and then lease rates for the same older equipment. The result is that the purchased 360s stayed in use much longer than the ones IBM rented but in the end they all were salvaged and then scrapped but for a few.
I looked for but couldn't find a RS on the dynamics of the decline of the 360 installations but couldn't find any. I suspect there were three waves or salvaging, IBM off rent, leased/owned technogically obsolete and finally uneconomic due to operational costs. Who knows, there may still be a 360 someplace, probably a government installation, running an old applciation that should be replaced but the government can't or won't appropriate the funds. Tom94022 (talk) 18:06, 23 May 2019 (UTC)

Mystery Pugh reference[edit]

There is an external link to p. 323 ( of Pugh, Emerson W. (1984). "Memories That Shaped an Industry: Decisions Leading to IBM System/360", but that page is just part of the index. What is the relevance? Shmuel (Seymour J.) Metz Username:Chatul (talk) 02:33, 14 June 2020 (UTC)

It means that the book is 323 pages long, not that one should read page 323. Gah4 (talk) 05:56, 14 June 2020 (UTC)
In Template:Cite book, "page=" means "see this page" and "pages=" means "see these pages"; neither of them mean "this book has this many pages" - there is no mechanism in Template:Cite book to indicate how many pages the book has. The IABot assumes it means what it's documented to mean, and adds a page link if the book is in the Internet Archive.
I've fixed the external link not to use "page=" or to link to page 323. Guy Harris (talk) 08:12, 14 June 2020 (UTC)
I clicked on the link and it said, right there: pages: 323. In many other cases, it does mean how many pages, just not here. I don't think I ever made that mistake, though. Gah4 (talk) 19:55, 14 June 2020 (UTC)
It's not the link, it's the parameter, and the documentation for Template:Cite book clearly says that page= is for a page containing the reference information and pages= is for multiple pages containing the reference information - and that pages= is not to be used for a page count.
The bot assumes that page=/pages= is being used for that purpose, not a page count; if it happened to make the page part of the citation link to a page that happened to say "this book has 323 pages", that's purely coincidental, not intentional.
So nobody should ever put the page count after page= or pages= in a citation template, and, if that's ever been done, it should be fixed not to do so. Guy Harris (talk) 22:08, 14 June 2020 (UTC)

no IBM 2260 on System/360[edit]

I just removed some recently-added text which implied that the IBM 2260 is used as the console typewriter on some models of System/360. This is incorrect. While the IBM 2260 can be used as an additional operator interface, it does not replace the console typewriter John Sauter (talk) 16:41, 14 July 2020 (UTC)

As well as I know it, maybe from OS/VS2, a system can have a master console and also secondary consoles. As the mentioned text didn't say master console, it seems to me that it was fine, but mention of the 2260 as a secondary console would also work. I remember them from public access consoles that allowed one to check on the status of a job, but not change things. I believe that was for ASP. Gah4 (talk) 17:21, 14 July 2020 (UTC)
It is incorrect that the text made such a claim. That text followed the text for the 2250, which is also not a typewriter.
The console typewriter on a S/360 is just another I/O device. The 1052-7 was ubiquitous because it was inexpensive, and had no privileged role. In a Multiple Console Support (MCS) configuration, the normal role for the 1052-7 was as a hardcopy console, with displays serving as master and secondary consoles. This is different from the role of the 3210 and 3215 on some S/370 models. Shmuel (Seymour J.) Metz Username:Chatul (talk) 17:50, 14 July 2020 (UTC)
The console typewriter was integrated into the CPU, though it appeared to software as though it were on channel 0. I have clarified the text, separating the primary and secondary consoles into separate paragraphs. John Sauter (talk) 16:33, 15 July 2020 (UTC)
The 1052-7 was optional on, e.g., the 360/65. The 2250 was integrated with the system console on the 360/91, 360/95 and 360/195. There was also an option for two 1052-7 attachments, although I never heard of anyone procuring it.
Would mentioning composite consoles (card reader and printer pairs) be TMI? Shmuel (Seymour J.) Metz Username:Chatul (talk) 19:23, 15 July 2020 (UTC)
Probably. It's not a hardware feature anyway. Peter Flass (talk) 20:11, 15 July 2020 (UTC)

Feature 5450 on 360/85 and 3066 on 370/165[edit]

@Peter Flass: The 5450 and 3066 consoles have different keys, CCW opcodes and data streams from a 3270. If you look at the logic manual [1] you will see that DIDOCS has a separate driver for 5450 and 3066. If you have a copy of the VM turnkey system, you can also check the code in CP and in CMS EDIT.

These consoles are documented only in the 360/85, 370/165 and 370/168 CE manuals. I had copies of the CE manuals for the 3165, but I sent them to the LCM for scanning in 2014 and have not yet gotten the PDFs. Maybe you can track down another copy.

Shmuel (Seymour J.) Metz Username:Chatul (talk) 05:38, 15 July 2020 (UTC)
I didn't think about VM, but the code there would certainly be clearer. Peter Flass (talk) 20:12, 15 July 2020 (UTC)
I did some more digging around, and the Amdahl 470V manuals not only documented the commands but gave a reference[2] to an IBM manual that is on bitsavers. Shmuel (Seymour J.) Metz Username:Chatul (talk) 01:02, 16 July 2020 (UTC)
Thanks, that’s interesting.So it was a completely different beast from a 3270, not just a 3270 with a bigger screen. I never saw one in real life. I never came close to an /85, and don’t think I never made it into the computer room when we had a /168. Peter Flass (talk) 02:49, 16 July 2020 (UTC)


  1. ^ IBM System/360 Operating System MVT Supervisor (PDF). Program Logic (Eighth ed.). IBM. May 1973. GY28-6659-7.
  2. ^ "System Console with CRT Display" (PDF). IBM System/370 Model 168 Functional Characteristics (PDF) (Fifth ed.). IBM. January 1976. pp. 26–30. GA22-7010-4.