Alps SKCL/SKCM series
The ALPS CM switches are the most common type of ALPS switches. The "bigfoot" nickname has been given to these switches by the administrator of the Japanese website [Mousefan], and has since become the most popular name for these switches.
Variants
First introduced as early as 1984, the ALPS CM switch has been one of the first commonly available, compact-design keyboard switches. Over the years there have been several variants of the keyswitch, including changes in color and design. Early variants of the ALPS switch did not carry the ALPS logo on the top part of the case, and only had it stamped in on the switch bottom. The most major difference being an entire redesign of the inner workings. These two different types of switches are generally being referred to as complicated and simplified.
Complicated
The first versions of the ALPS switch have been nicknamed as "complicated" switch or "Type I" switch. This variant includes many complicated internal parts and consists of at least 7 individual pieces, excluding the switch housing. The complicated switch can be easily identified by the bigger sized click-leaf and the complex contact construction. When looking at original ALPS CM switches (excluding clones), it is also safe to say that switches without a logo are generally the older, complicated variant.
Simplified
The simplified version of the switch consists of a much more simply construction. Compared to the complicated variant, the click-leaf has been drastically reduced in size and the contact-mechanism has been changed. Simplified ALPS switches seem to have first appeared around 1988 and have been cloned by many other manufacturers.
Colors
ALPS switches came in many color variants, most of the time used to define the switch type. Despite being a pretty good rough guide, ALPS did not always stick to their color-codes and seems to have changed colors randomly for reasons unknown. All of the colors listed below refer to the stem of the switch.
Blue
The blue ALPS CM switch is the first switch of the CM series introduced to the mass market. It is a clicky and tactile switch. Blue CM switches generally do not have the ALPS logo engraved on the top part of the switch case. This switch seems to have been mostly replaced by the almost identical white switch starting in 1987 or earlier. Some people believe the blue switch to be more smooth than the white one.
White
The white ALPS CM switch is one of the most common ALPS switches. It is a clicky and tactile switch existing in both a complicated variant, as well as a simplified variant. Early versions do not yet show the ALPS logo on the top part of the case and seem to be identical to the older blue ALPS switches. The newer variant, has a slightly different contact plate.
Trivia
The Playstation 2 game controller for Guitar Hero uses a cloned ALPS switch (XM Type) for one of the control buttons.
