Factual updates and other interesting changes are reported here. Adjustments and tweaks are not listed.
Updates for 2019
Sunday, 21st April
Saturday, 20th April
Wednesday, 10th April
Kiyoto has located a set of Japanese patents relating to Fujitsu leaf spring. I have tentatively reclassified the various leaf spring types according to the suggested chronology from these patents, but there is still a long way to go.
Monday, 8th April
My TESLA Hall effect switch and some TESLA keycaps arrived from 10ko in Bulgaria today. I have no idea what happened to the switch (the plunger has been sliced narrow and now it is quite wobbly) but the keycaps are intact, and these and the switch permit keycap mount comparison between Micro Switch, TESLA and Omron. These three brands have very similar keycap mounts that are almost but not quite compatible, for different reasons.
These types are now detailed under the new keycap mounts section. Unlike the existing keycap compatibility page, this section places each group of similar mounts on a separate page for simplicity and to permit more details to be recorded.
This section (like any other) will be expanded upon over time.
Saturday, 6th April
Kiyoto is on a roll. He has located a large number of Fujitsu datasheets on their site, including the datasheets for Fujitsu FES-360 Series, which is first-generation leaf spring. FES-360 Series is still in production, but only for existing customers. It seems to be a fairly small series, offering 59 cN momentary action only, although the oldest PDF for it is from 2001, so it may be that other models were long since discontinued.
Thursday, 4th April
Kiyoto (聖人) sent me a link to the datasheet (or catalogue entry) for Fujitsu FKB2500 Series. Although it does not offer any clear insight into Fujitsu’s naming and classification system, it does match the suggested naming arrangement listed under Fujitsu keyboard series. It also offers the first specifications on a Fujitsu mechanical switch type.
Monday, 1st April
Posted a list of keyboard types discovered to date in Roland and Yamaha service manuals, along with Yamaha non-keyboard types. The Roland non-keyboard types will be added later when time permits. This page represents some of the raw data already presented under Alps series names and model numbers.
Also included is the first confirmed instance of an Hirose Cherry M83S, specifically the standard part M83S-0N00 as found in the Yamaha QX21 (1.5 mm travel version).
Sunday, 31st March
As noted under wiki errors, US patent 4529849 is incorrectly cited as being the patent for second- and third-generation leaf spring. In fact, it is the patent for the membrane leaf spring types. Membrane leaf spring has been mentioned at least once—as “4th gen Fujitsu leaf spring”—but not depicted.
Kiyoto in Japan has demonstrated that the Fujitsu FMR-30BX has a moulded Fujitsu membrane leaf spring keyboard, as documented in the patent. It is possible that the integrated-membrane type shown in the patent was changed to use a modified form of the existing contact assembly from the original leaf spring switches.
Thursday, 28th March
- Added a brief page on Cherry M8, MD and MJ series, along with the end-of-life notification for M8 and M85.
- Added all the M8 types from the end-of-life notification to the Cherry parts page, along with the custom MX types and the two known M9 types.
- Updated the M8 schema and common schema pages to reflect the fact that German custom M8 types are now confirmed to exist (as given in the end-of-life notice).
Sunday, 24th March
The Fujitsu date codes and Fujitsu keyboard series pages are both updated with additional examples. In the latter case, this includes 3100 and 3700 (ultra-flat leaf spring keyboards), 8000 and 8200 (tall reed), 9200 (reed that might be shorter) and 2300 (third-generation leaf spring). 2700 is removed for now, as it referred to a single photo that did not show the switches.
Thursday, 21st March
Having received two SN Series switches from STRONIC in France (101SN11 and 201SN1B1, with the latter in its original packet), it has become clear that these are identical to SW series, except for having a base to hold them together for PCB mounting.
Wednesday, 20th March
Since the SMK series and part numbers page does not offer any illustrations, a separate SMK series page is now posted with illustrations of the known series, mostly taken from SMK’s catalogue pages. In particular this includes KBS03 Series, the membrane-based alternative to the better known KBG family (which looks similar but uses conductive domes over a PCB).
Sunday, 17th March
Finally written up and illustrated the dual-magnet tactile and click mechanism of the Omron B2H-F7W Hall effect switches that I obtained in September last year.
Sunday, 10th March
Re-inspection of the Hirose M83S, M83A, MD and MJ series datasheet shows that the force figures are not indicating the permissible manufacturing range, but in fact the tolerance (as recently determined for US M4/M5/M6). The Cherry common schema page along with the MD and MJ schema pages are updated accordingly. The range for MD, 50〜80 gf, comes out at 65±15 gf, and 65 g is what the Epson PX-8 Technical Manual gives for its standard weight MD switches.
Saturday, 9th March
MEI T-5 subseries T-5D has since been confirmed to exist, and is presently on order from Datalux. Once these arrive (Brexit willing) it will be possible to see what they are.
Friday, 8th March
- Phosphor bronze is added to the materials page, under a new spring materials section.
- There is now a Hi-Tek/NMB section; more will be added later. The details of the liquidation of Minebea keyboard subsidiary Shanghai Shunding Technologies Ltd is moved from now deprecated factual nuggets page.
Wednesday, 6th March
- The MEI T-5 page is updated with a list of currently available parts (all on order from Datalux) and the part number schema.
- Tenite™ is added to the materials page.
Tuesday, 5th March
- There is now a Micro Switch/Honeywell section. At the moment this comprises a single page put there to contain the theory that SD16 series corresponds with switches whose sub-part number begins “16” (as found in MouseFan’s Sun Microsystems SD keypad).
- Vintage ABS notes are moved from the deprecated factual nuggets page to the materials page.
Sunday, 3rd March
- List of confirmed MEI T-5 parts added.
- Added a brief page on Clare-Pendar Series S880, to have somewhere to put the link to the YouTube video showing an excerpt from Electronic Design magazine that mentions it.
- Added also a page for Clare-Pendar Series S820.
- Added a section on “PWB” to the Alps keyboard codes page.
- Posted a brief history of Mechanical Enterprises, along with a list of relevant patents and what they apply to.
- MEI Mercutron page is added, listing the patents and what they appear to correspond to.
Saturday, 2nd March
Added newly-discovered T-5V subseries to the MEI T-5 page.
Friday, 1st March
- LFW is now confirmed to be a series (LFW-CT will be a switch model).
- Mechanical Enterprises page updated with the newly-discovered switch series: Mercutron family (including M-5), LM, and LFW (changed from LFW-CT).
- “WEAB” is added to the mysteries page, as years are passing and it remains persistently unresolved.
Thursday, 28th February
- Added the first mention of MEI LFW-CT.
- Added a mention of Don Lancaster’s 1976 book TV Typewriter Cookbook to the T-5 page also, as “T5” gets a mention there (giving us a low water mark for age).
Tuesday, 26th February
- There are now separate M4/M5/M6 schema and M7 schema pages, for convenience, as these are two separate series.
- Explanation of weight ranges for US M4/M5/M6 switches (they refer to tolerance and approximately match the German tolerances).
Sunday, 24th February
- Added the Clare/GI/Pollak/Electro-Mech CAGE code (97564) to the Clare/Pendar page to clear up the mystery of that number marked on switches.
Friday, 22nd February
- Alps OEM model numbers page uploaded, albeit with just two items for now.
Tuesday, 19th February
- Initial list of Key Tronic product codes posted, in an attempt to understand their structure or meaning.
Saturday, 16th February
- Added Newtech YMW, GoldStar YYWW, Intel YWW and Mitsubishi YYWW to the IC dates page along with a copy of the image grid from the Keycombo dating page.
Wednesday, 13th February
- IC dates page updated following determination that Texas Instruments’ three-digit date format represents YWW as expected.
Tuesday, 12th February
- Added a page on Mitsumi models, derived from the list previously posted to the wiki, and extended to cover KCD-A65YU (found in the Commodore SX-64).
Sunday, 10th February
- HFO added to the IC dates page.
- Alps series names and model numbers page updated to note that CM series may have also been called KCM.
- Added a page on Alps PCB codes; for now this is just a stub, but the Olivetti 11K code incompletely documented at Deskthority is moved to this page.
- Added a very brief page on http://telcontar.net/KBK/Oak Series 400.
Saturday, 9th February
- Started a page on IC date information, to help people date ICs and thus keyboards and indeed other equipment. More formats will be added over time.
Sunday, 3rd February
- Travel and hysteresis mentioned on the glossary page, as well as on a new Travel, actuation and hysteresis page (the latter being mostly created just to have somewhere to report on the useful information from the General Instrument S700 Series patent).
- Honeywell mount added to the keycap mounts page (as there is a patent for it).
- Switch design characteristics page updated with a brief mention of buckling rubber sleeves, as there is a 1970 patent for those, too.
- Added a brief guide to reading the header fields of Japanese patents.
Wednesday, 30th January
Tuesday, 29th January
- Added a page on SAGEM keyboards.
Sunday, 27th January
- Added a page on common keyboard switch characteristics to help with lay identification purposes.
Friday, 25th January
- Glossary updated.
Sunday, 20th January
- Added a page on TGL standards.
- Added a page on the HFO B 461 G Hall sensor IC used in RFT and RAFI switches.
- Updated the RFT TSH 19 page with brief details on the two variants.
Monday, 14th January
- Started a page on East German manufacturer RFT.
- Started a page for RFT TSS reed switches.
- Added a stub page for RFT TSH 19 Hall effect switches.
- Use of rhodium as a contact material is now mentioned on the materials page.
Saturday, 12th January
- Materials page gains a recreation of Cherry’s contact material selection chart as well as some additional details on material choice.
Wednesday, 9th January
- Updated the Cherry MX page with the years from Hirose.
- Updated the Cherry M7 page with Hirose’s M5 and M6 years.
Sunday, 6th January
- Added MX Olympia Linear Clear to the MX variants page, and revised the page a little.
- Changed the Cherry MX notes page to be the main Cherry MX page, and added a brief table of historical occurrences relating to MX.
Wednesday, 2nd January
- Updated the Cherry gold crosspoint/M7 design page with illustrations and greatly expanded content.