KBK update for Tuesday, 25th January
The Alps series names and model numbers page contains what until now was my current understanding of that subject. An accidental discovery on Google Books has cast some doubt on this. Switches resembling those that became known as KCC Series were advertised in JEE (Journal of Electronic Engineering) in 1978 and 1979 as either “AKC2C” or “AKC2N”: both types are depicted seemingly identically (the scan quality is poor) and share the same brief description. There is no way to determine whether they are variants within the same series, or two separate series sharing the same housing (which we know to have existed).
Although one could argue that the S-codes (SCB, SCF, SCH, SCK) only represented internal assemblies, SCK is definitely used differently. Roland service literature gives codes SCK41168 and SCK41167, not for switches, but for switches combined with relegendable keycaps. There is also SCK-41097, suggested to be solely a switch.
AKC itself is presently taken to be the original spring bridge type, of which KCC is taken to be the replacement type. It may be that Alps briefly dubbed it AKC2 (there is also the non-keyboard AKC8, which is a miniature TACT switch, with subtypes AKC8S and AKC8N advertised in JEE), before formulating a new series naming system. However, this still offers no further insight into the S-types and how these came to exist in parallel to AKC, AKB and AKM.
This mystery appears to be deepening rather than becoming clearer. None of AKC2, AKC2C or AKC2N can be tracked down, although an archived LG/Zenith parts listing with an entry of “SWITCH AKC8S W/O CAP/SKHCAA20” indicates that AKC8S became SKHC, and the two look the same. (AKC8N seems to have become a different series.) The fact that the AKB-3420 and AKB-3320 literature did not name the switches used deprives us of observing what switches went with SCH-type keyboards. All we know is that AKB and SCH were noted together in the manual for these keyboards and CH was used for the PCB code. With Google, Google Books and the Internet Archive all exhausted, it may be a while before anyone encounters a source of answers.
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