Talk:IBM 308X

Neither of the photographs are pertinent to the IBM 308X series

The TROS predated the 308X by 14 years, as is clearly visible in the picture. The SLT is from a Model 1800, which predated the 308X by 16 years (see: []) — Preceding unsigned comment added by Tsgsh (talk • contribs) 15:11, 28 October 2019 (UTC)

A photo of a horse pulling a wagon in an article about the unit of measure called horsepower (or similarly a candle to adorn something about candlepower) is part of why some chefs use multi-color pasta. The wording on the photos show that the items are illustrative of the past: they're saying that 308X technology was successor to these yester-year items. Pi314m (talk) 00:10, 7 November 2019 (UTC)

Its technology is the successor to a number of technologies; the relevance of TROS to a system using semiconductor RAM for its microcode, or SLT circuits to a system using LSI, seems no clearer to me than the relevance of vacuum tubes from an IBM 701 or transistors from an IBM 7090 to the latter system.

This is IBM 308X, not History of computing hardware (1960s–present) - the discussion of differences between it and its predecessor, the IBM 3033, in IBM 308X#3081 as successor to 3033 makes sense, but comparing with mid-1960's technology from at least three System/3x0 generations back (S/360 -> S/370 Model 1xx -> 303X -> 308X) doesn't seem to add much of use in an article about this particular line of computers, as opposed to a general history of computing, IBM mainframes, or System/3x0 mainframes (x = 10 for z/Architecture :-)). Guy Harris (talk) 00:30, 7 November 2019 (UTC)

How was 370-XA added to the 308X machines?

The 3081 came out in 1980, but 370-XA came out in 1983.

Did all of the 308X models have the necessary hardware to translate 31-bit addresses in XA mode, with a microcode update introducing -XA? Or were hardware changes required?

Or was it just newer 308X models that supported XA? Guy Harris (talk) 21:40, 5 August 2025 (UTC)

Or maybe there was no update required other than an OS update to enable and support XA? Guy Harris (talk) 21:41, 5 August 2025 (UTC)

@Guy Harris:I added the announcement letter to IBM System/370-XA. -- Shmuel (Seymour J.) Metz Username:Chatul (talk) 10:16, 6 August 2025 (UTC)

That announcement letter says "All models of the 3081 Processor Complex will be capable of two modes of operation starting April 1983", so presumably they all had the necessary hardware in the MMUDAT hardware and either 1) got a microcode update, 370/145-style, or 2) and the necessary microcode and got an OS update.

I'm guessing this applies to the 3083 and 3084 models as well. Guy Harris (talk) 19:48, 6 August 2025 (UTC)

Given that the 3083 and 3084 were announced a year after the 3081-K, it seems like a safe bet that it apples to them as well. I have no information as to whether the XA support required a hardware EC or just a microcode update. Exploitation of the upgraded software required installing new program product versions of the operating system, e.g., MVS/XA, Virtual Machine/Extended Architecture Migration Aid (VM/XA MA).

OT - the terms introduced and starting, used in many articles, are ambiguous; they could refer to either announcement date or ship date. -- Shmuel (Seymour J.) Metz Username:Chatul (talk) 12:55, 7 August 2025 (UTC)

References