Talk:KL10

MC at LCM

I thought MC went to Sweden; how did it end up at the LCM? Jnc (talk) 16:23, 24 June 2019 (CEST)

That's right, it did. It remained for many years in Peter Löthberg's storage. But last year most of the computers there, including MC, was moved to LCM. Larsbrinkhoff (talk) 19:47, 24 June 2019 (CEST)

Figured; didn't his KI10 wind up there too? Jnc (talk) 21:29, 24 June 2019 (CEST)

Yes, parts of the dual and sometimes triple processor "KICKI". And also KATIA (literally "KA-10" in Swedish), a CADR, and some other goodies. Well worth a visit if you're in town; ask for the basement tour. Larsbrinkhoff (talk) 07:01, 25 June 2019 (CEST)

Microword

Someone who looked at the schematics claims the microword width was 75 bits on the model A, and 76 on the model B. The additional bit is used to implement an improved CALL instruction. Larsbrinkhoff (talk) 07:29, 6 July 2019 (CEST)

Yeah, I vaguely recall something like that.

I really wish there was a single document one could consult which covered all the variants, and gave the differences, but no, it seems like one has to read through everything that's left to find it all. And then there are things like the S-Bus/X-Bus switch; it would be nice to have something which says what the differences are (surely such a doc would have been useful BITD; for people who already know the S-Bus, read that, and you're done), but it looks like we're going to have to read the descriptions of both, and work out what changed. Sigh. Jnc (talk) 15:54, 6 July 2019 (CEST)

Version confusion

So EK-0KL20-IN-001 ("KL10-Based DECSystem-20 Installation Manual") gives, in Section 10.2 "KL10-PV Upgrade Procedure for KL10-C" instructions which clearly include the replacement of the main CPU backplane. However other documents make it sound like the Model B supports multiple sections. So now I'm completely confused as to the whole multi-section thing; I thought it came in with the Model E (AKA KA10-PV), and needed a different CPU backplane, but maybe not? Is the KL10-E different physically from the Model B, or not? Jnc (talk) 01:05, 7 July 2019 (CEST)

E.g. in AD-H391A-T1 ("DECSystem-10/DECSystem-20 Processor Reference Manual"), it says (pg. 1-2) "The {KL10} exists in two versions, with and without extended addressing". So maybe the Model B supports sections? So is a 'KL10-C' a Model A processor? If not, why does the KL10-PV upgrade need to replace the CPU? Very confusing. Jnc (talk) 01:20, 7 July 2019 (CEST)

As further data, the "1080, 2040, 2060 Engineering Functional Spec" discusses sections, so it sounds like the Model B supported sections from the start? Or perhaps the hardware had the necessary support, but it needed upgraded microcode which was not available at the initial Model B release. (It's not clear if that document refers to the Model A or not; given the discussion in there of the RH20, not present on the Model A, probably not. The again, since the 1080 apparently used a Model A - the model numbers are confusing too - who knows?) FWIW, the ucode version history shows that section support was added start in rev 201 ("BEGIN EXTENDED ADDRESSING CHANGES IN EARNEST"). Jnc (talk) 01:57, 7 July 2019 (CEST)

I also think it's confusing, but the way I have seen people talk about this, my theory is these are one set of models: KL10-PA, KL10-PV, and KL10-PW. I believe the first is the non-extended, and the second to have extended addressing. The last one has a bigger cache.

Then there is another set of models: KL10-A, KL10-B, KL10-C, KL10-D, KL10-E, KL10-R. A/B/C had KL10-PA, the others PV or PW.

Finally "model A" and "model B" is yet another thing. Model A is the KL10-PA without extended addressing, with a "model A backplane", and just 1280 words of microcode store. Model B had extended addressing, another backplane, and 2048 words. Larsbrinkhoff (talk) 10:23, 7 July 2019 (CEST)