Alps naming woes

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Daniel Beardsmore

07 Mar 2018, 23:27

According to the Apple III service manual, the switches in the Apple III are "KCC" (momentary and alternate action) and "KFF" (double action).

So now we have three naming formats for Alps series:

Two-character: CL and CM, from's photo and from the 1994 Alps catalogue
Three-character: KCC and KFF, from the Apple III service manual
Four-character: SKCL/SKCM (from a late 90s Alps datasheet), SKFL (from some lunatic selling surplus switches), and SKFR and SKFS (1994 Alps catalogue)

So even in the 1994 catalogue, Alps were apparently not consistent. I thought that the format like "KCC" / "KFF" was for keyboards, not switches (later KF* instead of K*).

At least now vertical plate spring is proved to be (S)KFF as assumed.

Also, the service manual lists Datanetics switches:

DC-51-31 for most keys (unknown, unexplained type)
DC-51 alternate action (for alpha lock)
DC-51 dual action (new discovery; for the arrow keys)

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ALPS キーボード

08 Mar 2018, 15:13

I think it's not as complicated as it seems, S could easily just stand for "switch" and so Switch KCC would be abbreviated down to SKCC. Something else to keep in mind is that Apple tends to overcomplicate for the sake of obfuscation or just because they can, so it's not unlikely that Apple just took the name and renamed it for their own uses.

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Daniel Beardsmore

09 Mar 2018, 00:03

More confusingly, "SK" stands for "single key switch" according to the 1994 catalogue according to Sandy, although I suspect Alps just made that up, or they just liked how it could be expanded in English. It's not "switch, keyboard" (there are SK-- parts that are not keyboard switches), but the keyboards that used SK-- omitted the S. So you'd have keyboard KCC-- with SKCC-- switches. Except Apple left off the 'S' in the switch series names. And Alps left off S and K for CM and CL series. But often the keyboard would be (e.g.) KFCC-- with an F added. Often, but not always.

Blue Alps is model SKCMAG within CM series, so the series name does not have to begin "SK". However, Alps later used "SKCL/SKCM series" (in Japanese) instead of CL and CM. However, they used CL and CM at the same time as SKFR and SKFS, so it seems that some series got shorter names and others were left with the full four-letter name.

Basically, our series names (SKFL, SKCC, SKFF etc) are all just guesses. They're pretty likely to match the part numbers, but Alps didn't necessarily call each series directly according to the part numbers. Rather, the series names could have been shortened in various ways, and the latest information means that guessing correctly is even harder than it seemed.

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09 Mar 2018, 00:08

Which source is closest to primary? Not Apple. I would trust a translated Alps catalog before anything a technical writer at Apple interpreted, from whatever source.

The point of translation is also going to account for variances. I doubt the same people worked at Alps, or the American firm that did the translations.

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Daniel Beardsmore

09 Mar 2018, 00:23

You're assuming that Alps were self-consistent at any point, or consistent year upon year. I only have one person's interpretation of the 1994 catalogue, as I've never been allowed to see most of it (whoever obtained it originally was denied permission to post it online). Also, companies can't decide how to format their own part numbers half the time either. Or even their own name! And that can change. Maxi-Switch vs Maxi Switch, Key Tronic vs KeyTronic …

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Daniel Beardsmore

18 Mar 2018, 00:13

OK, this is weird …

The "Apple II Switchable Keyboard" used Alps KBB switches : ... 201981.pdf pp. 340–342

I wonder if that is a mistake, as Alps (S)KBB does not make sense.

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