Talk:IBM System/360

Feature 5450 on 360/85 and 3066 on 370/165

Template:Ping The 5450 and 3066 consoles have different keys, CCW opcodes and data streams from a 3270. If you look at the logic manual 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 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)

todo template?

The article contains the template Template:Tlx

This has two problems:

1. The template documentations says that it belongs in the talk page, not in the article.
2. The template documentation does not list an |other= parameter.

If I move the template as-is to the talk page, will it create and populate the IBM System/360/to do page? -- Shmuel (Seymour J.) Metz Username:Chatul (talk) 21:33, 17 May 2023 (UTC)

I started on the instruction formats here: User:Peter_Flass/sandbox#360 instruction set

The template is on the talk page; I don't see "todo" anywhere in the source of IBM System/360.

It was claimed to be empty; that was because it used other= rather than inner= to contain the list. I've fixed that.

But do those issues belong here? Now that we have IBM System/360 architecture, shouldn't that be the page that describes, in detail, instruction sets the interrupt architecture, and the I/O architecture, with IBM System/360 giving just an overview, along with the other stuff it has now? Guy Harris (talk) 23:22, 17 May 2023 (UTC)

You are right; that list appears to be extremely old. -- Shmuel (Seymour J.) Metz Username:Chatul (talk) 06:50, 18 May 2023 (UTC)

Compatibility Operating System?

While the original emulator programs prior to the 360/85 ran standalone, IBM later offered Compatibility Operating System (COS) options for running IBM 1400 series under DOS/360 on a 360/30 or 360/40 and 1410/7010 under OS/360 on a 360/50. -- Shmuel (Seymour J.) Metz Username:Chatul (talk) 13:59, 31 May 2024 (UTC)

Multiple issues in permalink/1281322478

Edit permalink/1281322478 changed Template:Tqq in Template:Alink to Template:Tqq. However, every model of the S/360 include more than the CPU, either in a single frame or in multiple frames, e.g., coreTemplate:Efn and I/O channels.

The edit also added Template:Tqq to the beginning of the next paragraph, although the old text was already incorrect. There was no S/360 model in which some instructions were implemented in hardware and some in microcode. On the smallerTemplate:Efn models and 360/85 all instructions were implemented in microcode and on the larger models other than the 360/85Template:Efn all instructions were implemented in hardware.

Channel on everything through 360/50 were implemented in microcode and channels on the 360/65 through 360/195 were implemented in hardware residing in separateTemplate:Efn frames. -- Shmuel (Seymour J.) Metz Username:Chatul (talk) 20:49, 19 March 2025 (UTC)

"Implemented in hardware" is a bit of a fuzzy concept. As far as I know the microcoded S/360 machines all have a fetch-decode-execute loop in microcode, but, on some if not all machines, there might be hardware data paths that reduce the amount of work that the microcode has to do to decode or execute instructions. For example, a lower-cost machine might not have data paths that assist floating-point arithmetic and a higher-cost machine might. (For example, the 360/65 - and, presumably, the 360/67 - has a parallel adder for binary integer arithmetic and floating-point mantissa arithmetic and a serial adder for floating-point "charistic" (characteristic?) arithmetic (both are used for variable field-length operations) - see the IBM FE data flow diagram for the 360/65.

(The channel thing is a bit interesting - I guess, when they were designing S/360, channels independent of the CPU were a high-end-computer thing, but they presumably wanted I/O to work the same on all models, so, on the lower-end machines, they implemented non-independent channels that steal CPU cycles.)

(Oh, and you probably meant "Except 360/95, which had thin film storage." in the first footnote. :-)) Guy Harris (talk) 21:57, 19 March 2025 (UTC)

Yes, there was considerable variation in how much hardware was available to the micrcode and in the width of internal registers. The F/D/E loop disappeared on the 360/85, which had a separate I-unit.

Yes, external channel boxes were the norm on the 7000Template:Efn series, and the S/360 PoOps manual definitely requires that channels look the same regardless of how they are implemented.

Thanks for catching the typo. -- Shmuel (Seymour J.) Metz Username:Chatul (talk) 13:42, 21 March 2025 (UTC)

Should footnotes include the abortive models 60, 62, 54, 55, 70, 90 and 92? -- Shmuel (Seymour J.) Metz Username:Chatul (talk) 14:14, 21 March 2025 (UTC)

In my opinion, model numbers that were announced but never shipped should be mentioned but when referring to actual computers they can be omitted. Thus, models 60 and 62 were replaced by model 65, models 64 and 66 were replaced by model 67, model 70 was replaced by model 75, and model 90 was replaced by model 92 which was replaced by model 91. John Sauter (talk) 21:21, 22 March 2025 (UTC)

Hatnotes and see also?

Should there be hatnotes mentioning Template:Hlist? See also entries? The infobox does show them. -- Shmuel (Seymour J.) Metz Username:Chatul (talk) 14:03, 30 April 2025 (UTC)