1994 Alps catalogue

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A number of details on Alps switches come from a 1994 Alps catalogue that was circulated amongst Japanese keyboard enthusiasts, obtained around 2004 or 2005. The original catalogue was in colour, and was scanned to PDF. Black and white photostat copies were also made and passed to various people. The original catalogue and the PDF document are considered lost, as are all photocopies besides Sandy's, which is the only copy known to remain.

The catalogue is known to cover the following switches:


The owner of the catalogue asked Alps Electric for permission to republish it, and was denied. Photos provided from Sandy depicting parts of pages (but not whole pages) were posted to Deskthority and Geekhack before Alps's prior restriction was noted.

The SKCL/SKCM part numbers come from Sandy's transcript. SKFR/SKFS part numbers likely also came from Sandy; currently the only confirmed details are in an archive of geekhack wiki, which itself cited this same catalogue.[1]


Sandy provided the following notes in November 2013 (taken from a plain text e-mail). Whether they are verbatim or summarised is not known, and none of the explanatory text should be considered official Alps information without clarification.

It is interesting to note that the two series are given as "CL series" and "CM series" instead of "SKCL" and "SKCM", which partially corresponds with the catalogue fragment (from an older catalogue) that identified Alps SKCM Cream (SKCMAF) and Alps SKCM Blue (SKCMAG). Although "SKCL/SLCM series" was used in an official Alps document, this may indicate a terminology revision. (The text below is given verbatim, including typing mistakes and transcription errors. For example, "SLCLAQ" should read "SKCLAQ")

CL series ( All Linear) 
SKCLAR; Yellow, 0.588N 
SLCLAQ; Grey, 0.882N ( maybe be same one with space bar sw in Zenith ZKB-2
SKCLJC; Grey, 1.47N, Altenate type( referred as ALPS CM lock in deskthority )
SKCLFQ; Yellow with Red LED
SKCLFM; Yellow with Green LED
SKCLBB; White, Double action
CM series. Operating force;0.686N(70gf)
SKCMAP; Black, Without tactile sound
SKCMAQ; White, With tactile sound
SKCMAT; Green, Without tactile sound ( I haven't seen this one )
SKCMBB; Ivory, Quiet ( I suppose this one indicates rubber dumped sw used
        in SG AT-101. Dumped White ( in Apple EX-II) is not listed.

 ** Switching position and operating force diagram shows SKCMAT is quite different
 ** from others. operating force diagram is close to that of menbrane switch.  

CM compact is not listed in '94 catalog.

Coding explanations
SK stands for "Single Key Switch"
CL/CM, Contact structure and variety;
       Classification for contact structure such as circular, leaf spring,
       etc., and variety.
       ( no further information is given)
Last two letters, for Additional mechanism and variety;
       Classification by additional mechanism such as momentary, with LED,
       etc., and variety.   
       ( no further information given )

Switching regions

The switching regions for SKCM are given as follows:[2]

OFF region 1.5 mm 0.5 mm
OFF-ON switching region
ON region 1 mm 0.5 mm


  1. Geekhack — Default:ALPS switches (archive) Archived 2014-01-12. Retrieved 2015-07-22.
  2. Deskthority — Xerox with Tactile Green Alps