deskthority

Based on literature and PCB codes, we have so far (underlined = confirmed from literature):

Metal contact types:

KAM Type: standard mechanical type 1 (possibly momentary SPST only)
KCT Type: standard mechanical type 2, tactile (possibly momentary SPST only)
KDM Type: simplified (which are linear)
KLM Type: miniature mechanical, linear
KLT Type: miniature mechanical, tactile

(At a guess, "KAM" is "keyboard, original type, momentary, extended with "T" for tactile when that was introduced. Possibly KAA for type 1 alternate action, and pretty clearly KCM for type 2 linear. It is anyone's guess what clicky miniature is. I've not had chance to add "KAM" to the wiki yet.)

Hybrid types:

KSD Type: tall slider, membrane-over-PCB (preferred by Atari)
KSR Type: tall slider, PCB only (preferred by Commodore)
KKQ Type: short slider, PCB only, tactile
KKR Type: short slider, PCB only, linear
KPQ Type: short slider, single membrane, tactile
KPR Type: short slider, single membrane, linear

For these, the pattern is not clear. There are a variety of hybrid and other non-metal-contact types where we have no series name yet.

There are also a number of additional membrane laptop types, of which [wiki]Mitsumi KHK Type[/wiki] is the most interesting. Some are on the wiki, but more of them are not (on my to-do list).

Curiously, looking at the 1998 catalogue/1999 digital products library:

All the keyboards listed are non-discrete units.

That is:

"KPQ Type" — a type of factory-made keyboard assembly, that cannot be ordered from a warehouse (it has to be designed to order)

"KPQ-EA4YA" — a model from KPQ type

"SOR/SOJ Series" — tactile switches, radial taping type; this is a unified split series, where R or J denote subdivisions of a unified series instead of SOR and SOJ being wholly distinct; these have separate order numbers, e.g. model name code SOJ-173HS is order number R66 4687, which appears to explain why there are type 2 standard mechanical switches marked "E25-33-137" instead of "KCT-___".

"C8-FR, C10-FR, C13-FR Series" — three related series of power inductors (C8-FR Series, C10-FR Series, C13-FR Series), that do not follow the three-letter naming convention; these series are documented separately.


Consequently, it would seem reasonable that the switch types we have found so far might be:

KAM Series (if it covers all types)
KAM/KAA/KAD Series (hypothetical, to cover alternate and double action)
KCM/KCT Series
KDM Series
KLM/KLT/___ Series (blank covers the clicky switches that are yet to be examined)


Therefore, it seems that using the term "xxx Type" for all the non-discrete arrangements is within reason, but for discrete switch keyboards, it may be a bit of a stretch, although it still seems apparent that switches and motherboards shared the same type/series identity.