Talk:OS/360 and successors

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The first few threads have been copied from Talk:OS/360 as OS/360 is now redirected to OS/360 and successors.

Contents

[edit] A disaster?

I don't think it's wholly unreasonable to tag this with Category:Software engineering disasters - although now that I look at the contents of that category, I'm reconsidering! It was extremely late, extremely over-budget, extremely over-sized - you name it, along almost every axis it was a nightmare. A smaller company might have been sunk by such a problem - and many were, by smaller ones! Brooks himself had to step down from running the entire System/360 project to overseeing OS/360 to try and pull their irons out of the fire. Yes, it eventually got going, and was not too bad - but as Milo Medin's saying goes, "with enough thrust, anything will fly". Noel (talk) 03:49, 17 August 2005 (UTC)

[edit] Restructure of articles about IBM mainframe operating systems

After a big edit of MVS I concluded that the whole set of articles about IBM mainframe operating systems from System/360 onwards needed to be re-structured to minimise overlap and to make clearer the evolutionary relationships between these operating systems (notably in memory management, which is historically a major distinguishing feature). There is already some support for this proposal. Please add comments at Talk: MVS. Philcha 23:56, 20 October 2007 (UTC)

[edit] Rewrite of Job Control Language in progress

As part of the proposed restructure of articles on IBM mainframe operating systems (above), I've rewritten Job Control Language to: cover IBM's DOS/360 and its descendants as well as OS/360 and its descendants; focus more on the facilities and flavour of the 2 JCLs rather than on details of some statement types and some of their options. Please comment in Talk: Job Control Language. I'd be particulary grateful for more info on DOS/360 and its descendants, especially after 1980 - I only used DOS JCL a handful of times, and only in the late 1970s.

The rewrite does not currently take account of Truthanado's point in Talk: Job Control Language about use of "JCL" by computer suppliers other than IBM, which may entail further restructuring of articles about JCLs.Philcha 00:00, 21 October 2007 (UTC)

[edit] Merge with OS/360

Per discussion in Talk:History of IBM mainframe operating systems: proposition was to move OS/360 to a better name OS/360 and successors. No need for two articles with almost exactly the same topic. --Kubanczyk (talk) 15:39, 24 November 2007 (UTC)

Oops, I thought I'd made OS/360 redirect to OS/360 and successors. Must have forgotten click "Save". I'm doing it now. Philcha (talk) 15:45, 24 November 2007 (UTC)
Not too great. To remind you, the normal process of changing a page name is through a "move" function. There is a help there, which also explains why what you have done is not advisable. --Kubanczyk (talk) 16:11, 24 November 2007 (UTC)
Thanks, will use "move" in future. Philcha (talk) 17:52, 25 November 2007 (UTC)

[edit] Variants of OS/360

IBM maintained for a while that PCP, MFT and MVT were just different configurations of the same kernel (OS/360 Introduction), but that is not technically credible:

  • PCP (one job at a time) needs only one set of all the control blocks needed to define a job, and no precautions against 1 job interfering with another (memory, files, etc.).
  • MFT needs a fixed number of sets of control blocks; and needs precautions against inter-job interference.
  • MVT needs to allocate an indefinite number of sets of control blocks dynamically; and needs the precautions against 1 job interfering with another. Dynamic allocation means the top-level control blocks of each job will be scattered around in memory and therefore need to be linked list; while in MFT a simple fixed-length array would suffice.

In fact IBM gave the game away - OS/360 Introduction says "there are two configurations of the [OS/360] control program: ..." (MFT and MVT), which admits that PCP was different.

I'll rephrase accordingly. Philcha (talk) 22:02, 25 November 2007 (UTC)

Clarify, what are you talking about? What game? My previous point was not to force OS/MxT names too much, that's all. At least not without explaining to a reader that those were neither separate OSes or separate releases. It is per official creator's docs. --Kubanczyk (talk) 22:48, 25 November 2007 (UTC)
"there are two configurations of the [OS/360] control program: ..." (MFT and MVT) implicitly admits PCP was different; if PCP was just another configuration of the same kernel, OS/360 Introduction should have said "there are three' configurations of the [OS/360] control program: ..." Re MFT and MVT note at the wording in the article - "IBM maintained that ..." is very neutral. Philcha (talk) 17:41, 26 November 2007 (UTC)
Is this by any chance your original research? --Kubanczyk (talk) 00:23, 27 November 2007 (UTC)
The reasoning about the control blocks is, but the quote is from [OS/360 Introduction and clearly excludes PCP. Another IBM doc (ref in article) describes MFT and MVT as "separate versions". Philcha (talk) 07:54, 29 November 2007 (UTC)

[edit] Merge with MFT (operating system)

Support, but let's wait a while for another opinion. --Kubanczyk (talk) 23:04, 25 November 2007 (UTC)

[edit] Merge with OS/VS1

Oppose keep it as subordinate per Wikipedia:Summary Style; there is very specific info on that article; it would feel awkward on this page. --Kubanczyk (talk) 23:04, 25 November 2007 (UTC)

Support The amount of OS/VS1 info that isn't already in OS/360 and successors is very small: number of releases; the expansion pack to support new disks; withdrawal anouncement & MVS migration aid. OS/360 and successors already presents more info about OS/VS1 but concisely because it builds on the info about MFT. Philcha (talk) 09:34, 26 November 2007 (UTC)

[edit] Merge with MVT

Support, but let's wait a while for another opinion. --Kubanczyk (talk) 23:04, 25 November 2007 (UTC)

[edit] Merge with MVS

Strong oppose keep it as subordinate per Wikipedia:Summary Style; there is very specific info on that article; it would feel awkward on this page. --Kubanczyk (talk) 23:04, 25 November 2007 (UTC)

I suggest the best way to resolve this is to look around and see if there's much more to MVS/XA, MVS/ESA and OS/390 than the current Wikipedia articles state:

  • If there is a lot more, then I suggest we merge MVS/XA, MVS/ESA and OS/390 into MVS. I don't think it's useful to have many duplicated descriptions of multiple virtual address spaces, VSAM catalogs, tightly-coupled muiltiprocessing and JES2 and JES3.
  • If there is not a lot more, we should merge all MVS versions and OS/390 into OS/360_and_successors
  • Either way, keep z/OS separate. Philcha (talk) 12:12, 28 November 2007 (UTC)

Notes for MVS/XA (Google shows very few relevant hits for "MVS/XA" in 1st 100 hits):

  • [1] gives a lot of info and looks written by a competent author, but author name not given (Thierry Falissard, I think) and no guarantee that it will be around in 5 years.
  • IBM's [2] outlines the change in address space size.

Notes for MVS/ESA:

Notes for OS/390:

Philcha (talk) 13:10, 28 November 2007 (UTC)

[edit] Merge with MVS/XA

Better merge with MVS per above. Wasn't that the re-implementation of I/O subsystem? Introduction of subchannels/CHPIDs/...? --Kubanczyk (talk) 23:04, 25 November 2007 (UTC)

[edit] Merge with MVS/ESA

Better merge with MVS per above. --Kubanczyk (talk) 23:04, 25 November 2007 (UTC)

[edit] Merge with OS/390

Oppose keep it as subordinate per Wikipedia:Summary Style; there is very specific info on that article; it would feel awkward on this page. --Kubanczyk (talk) 23:04, 25 November 2007 (UTC)

Personally I'm happy to see all such members of the family on one page - with one exception: z/OS. And that's only because it's the current incarnation. Putting them together gives a nice sense of history: Them building on one another. Martin Packer (talk) 10:28, 26 November 2007 (UTC)

Yes you are right. Once again: Wikipedia:Summary Style. This guideline says that you can build a history here and have some detailed pages, too. --Kubanczyk (talk) 10:38, 26 November 2007 (UTC)
Kubanczyk, can you please clarify your last post. Do you mean you agree with the whole of what Martin Packer says (merge all except z/OS, which is also what I'd like to do) or are you still opposing merging in OS/390? Philcha (talk) 17:44, 26 November 2007 (UTC)
Hmm lets see... "Putting them together gives a nice sense of history: Them building on one another." -> "Yes you are right. ... you can build a history here and have some detailed pages, too". I agreed with Martin's last sentence, not with the merge proposition. --Kubanczyk (talk) 00:20, 27 November 2007 (UTC)

[edit] fred brooks + mythical man month...

isn't even mentioned in the article. nor is the number of programmers, etc. —Preceding unsigned comment added by 71.116.135.45 (talk) 22:56, 15 April 2008 (UTC)

Fred Brooks & "Mythical man month" are mentioned in History of IBM mainframe operating systems. Thanks for raising the point, it might be good to mention Fred Brooks & "Mythical man month" in OS/360 and successors too - but we'll wait until we see how the rest of the article develops, as it's potentially rather long.
Do you have a good source for number of programmers? That would be valuable in either article, and possibly in the articles on Fred Brooks and Mythical man month. Philcha (talk) 14:12, 16 April 2008 (UTC)