Discoveries

The following are some of my discoveries since 2012, thanks in no small part to the many people who have provided documentation and parts for inspection.

Contents

• Alps
• Cherry
• Clare-Pendar and General Instrument
• Datanetics
• Digitran
• Ericsson
• Futaba
• ITW (Licon and Cortron)
• Marquardt
• Mechanical Enterprises
• Micro Switch
• Mitsumi
• Oak
• Omron
• PED
• Philips
• RAFI
• Sasse
• SMK
• Tipro

Alps

• Discovery of the mid-80s Alps renaming exercise, during which three-letter keyboard and switch series (e.g. KCM, KFL) were split into separate switch and keyboard series (e.g. SKCM and KFCM, SKFL and KFFL) (2019)
• Identification of the “E” in 12KE codes as denoting elastic contact switches (formerly known as “integrated dome”)
• Identification of multiple Alps series:
  • SKCC, from keyboard PCB the keyboard PCB codes; this was previously KCC series, and earlier names for this series may include KBB and SCH (this remains a confusing mystery)
  • SKFL, from the keyboard PCB code on a Toshiba T3200 laptop keyboard PCB, based on photos from Nubbinator; this series was later found under its earlier name of Series KFL, for which two switch part numbers are now known
  • KFF, from a photo of a label on a Canon typewriter chassis, identified as SKFF back in 2016, but since corrected to KFF (2019)
  • SKCP, from a photo of a label on a Canon typewriter chassis
  • SKEW, from a photo of a label on a Canon typewriter chassis
  • SKPA, from seller photos obtained via UncleFan (2019)
  • KED, from Roland music gear (2019), due in part to listings by System J Synthesizers
  • KEH, from Roland music gear (2019), due in part to listings by System J Synthesizers
  • KCL and KCM as older names for SKCL and SKCM (as seen in a photo from alps.tw but not understood at the time)
• Discovery of Alps SCK series, thanks to photos from System J Synthesizers (2019)

Cherry

• Cherry M94A-1GBR (custom M9 type used in Bulgaria, being possibly used in the ИЗОТ ЕС 8531 М2КЛ)
• Cherry MD, MJ, M83A and M83S, and MX1A-0NNN thanks to Hirose for locating old documentation
• Differentiation between M81, M82 and M84: UncleFan figured out how to recognise M84 based on the catalogue, while the distinction between M81 and M82 came after Ed Ferraton passed onto us some sample M8 parts that I could disassemble and inspect, permitting confirmation that you can tell gold contacts apart from silver contacts
• Identification of the purpose of Cherry M1/M11, based on a Cherry drawing provided by Ed Ferraton, Datanetics parts and literature provided by Meryl Miller, and Findecanor’s prior observation in 2014 (2018)
• Identification of the keycap mount on Style D M7 switches (Clare-Pendar mount), after UncleFan sent me a switch for measurement (2018)

Clare-Pendar and General Instrument

• Discovery of Series S950, as a separate series to Alps SKCC, thanks to Electro-Mech Components for locating old Clare-Pendar documentation

Datanetics

• Identification of DC-60 series, which was identified after Invisius found a Fluke 1720A keyboard with a Datanetics-branded PCB, and snuci made sure it would come to my attention; from this I was able to stumble across Meryl Miller, contact him and obtain a wealth of old parts and brochures
• Identification of DC-50 series at the same time as DC-60 series was identified

Digitran

• Identified suggested Digitran keyboard series names and generations, with KS, KM “Golden Touch” and KD being the capacitive leaf types

Ericsson

• My disinclination to accept that “ICL” switches had anything to do with ICL led Jacob Alexander to finally check them for markings, which led to discovery of the series name (RMD 973) moulded into the base, and a logo which I recognised as the Ericsson logo rotated sideways (I later found the patent)

Futaba

• Discovery of tentative Futaba series names of MA, MD, ML and MR, and sub-series MA-41, MA-42, MR-6C, MD-4P, MD-7 and ML88, along with the brief specifications of these

ITW (Licon and Cortron)

• Identification of the DIN-compliant magnetic valve switches as being Devlin, formerly ITW
• Brief understanding of Licon and Cortron keyboard series names, with more data needed (2019)

Marquardt

• Identification of Marquardt series 6180 and 6184, thanks to Marquardt for locating old documentation

Mechanical Enterprises

• Identity of T-5 (“MEI WEAB”) and T-15 series
• Discovery of Mercutron (including M-5), LM and LFW, and DN series (2019)

Micro Switch

Much of the following was made possible thanks to charts from Honeywell Sensing & IoT and the Smithsonian Libraries.

• Discovery of additional SD Series types, as well as a greatly extended understanding of the series (2019)
• Discovery of additional SW Series types (including their “bi-level” double action design), as well as a greatly extended understanding of the series (including identification of the keycaps as 2SW subseries) (2019)
• Understanding of SN Series and its relationship with SW Series (companion series, not successor series) (2019)
• Identification of the switch series used in RW Series keyboards, being the reed subset of KB Series (2019)

Mitsumi

• Identification of various Mitsumi series and subseries based on parts supplied by Devlin (KLT-2 switches), catalogue pages held on the Wayback Machine (for some of the membrane and elastic contact types), and PCB codes; a full understanding still requires the relevant catalogue pages however (on the basis that KAM, KCT, KLT, KLM etc may form paired or grouped series names, as seen with some other Mitsumi types)
  • Membrane and elastic contact keyboard types:
    • KCD Type
    • KEK Type
    • KEL Type
    • KFK Type
    • KGL Type
    • KHK Type
    • KKQ Type
    • KKR Type
    • KPQ Type
    • KPR Type
    • KSD Type
    • KSR Type
    • KUJ Type
    • KUK Type
    • KUL Type
  • Mechanical keyboard and switch types:
    • KAM (“Type 1”, linear)
    • KCT (“Type 2”, tactile)
    • KDM (simplified)
    • KLM (miniature, linear)
    • KLT (miniature, tactile)

Oak

• Discovery of the first Oak switch series name, Series 400

Omron

• Discovery of B2R-M reed switches, found on AliExpress
• Discovery of Omron ball contact, found on AliExpress and Taobao
• Discovery of B2H-F7W (Hall effect with magnetic clicker), found after deducing that the switches found in some patents ought to be B2C or B2H

PED

• Identity of “PED” (formely Pye Electro-Devices) along with the patent for their switches

Philips

• Tentative identity of Philips “torsion spring” as Philips (and not Loewe) based on a similar patent from Philips along with the Loewe keyboard having the same Philips keycaps as seen in the patent; the series name however remains a mystery

RAFI

• Discovery of RS 74 M SPDT latching

Sasse

• Identification of Sasse series 25 and the possible Hall effect variant, found via a Web search

SMK

• Discovery of SMK J-M0404 (?) illuminated, found by searching Taobao
• Partial understanding of SMK series and part naming, based on datasheets held on the Wayback Machine

Tipro

• Discovery of Tipro SMK-style switches, donated by Tipro themselves