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KBK update for Friday, 1st January

2020 knowledge round-up

2020 has been a strange and ultimately disappointing year for reasons unrelated to the unexpected export from the Far East of something more dangerous than cheap electrical goods.

In terms of keyboard knowledge, it seemed fairly likely that 2020 was not going to top the level of revelation of 2019, and while this seems to be true, progress has continued in spite of everything. The big breakthrough was getting catalogues from RAFI in March for their RC 72 and magnetoresistive types, the latter being to date the only known example of magnetoresistive switches. This was the first but by no means the last instance of finding details that seemed highly unlikely to be found, showing once again that so long as you keep searching, you will find.

The RAFI discoveries then led to an in-depth investigation of German Hall sensors, not least because RAFI were offering a variety of output options not covered by the HFO B 461 G sensors that we have encountered thus far. Discussion with various people in Germany and examination of various websites and catalogues has allowed me to list out both the Siemens Hall sensor ICs and the HFO Hall sensors derived from them, although the early history of the Siemens types remains poorly understood.

Several years ago, Meryl Miller offered me an assortment of switches, and I selected just the keyboard types for myself and Jacob Alexander. More accurately, I selected the ones that I believed were keyboard switches, missing the fairly obvious Micro Switch KB reed switch (which was a solder terminal type, rather than the quick connect alternative that is all I have been able to obtain to date). Less obvious was a curious contraption that turned out to be Fujitsu FES-2. The real shame was in passing up a Raytheon keyboard switch. Extensive trawling through old electronics and computing magazines at Bitsavers turned up considerably more detail on these switches than expected, giving us the identities of KBSM for the mechanical switches and KBSR and KBFR for the reed switches. (In theory, KBFM—mechanical with a flat base—should also exist, but no sign of it has been discovered to date.) Only two KBSM switches have ever been seen: the one that Meryl has since discarded, and one that had already sold on eBay, from a seller too mean to permit the now-redundant photos to be published here.

Perhaps the most surprising discovery of all, was the names of several Stackpole series names, specifically KS-200 for the high-profile arrays, KS-200E for the low-profile arrays and the interlocking discrete switches, KS-500E for low-profile membrane keyboards, and finally KS-600E for the plate-mounted discrete switches derived from KS-200E. No mention has been found to date of a KS-100.

Keyboard enthusiasts are frequently acquainted with the method by which modern keyboards operate: the switches are wired in a grid (or matrix) and scanned by firmware stored within a microcontroller, with the key definitions stored within the firmware. Far less is known about the workings of keyboards going back to the 1960s, and the many ways of implementing a keyboard before the late 1970s when it started to become cost-effective to use a microcontroller. Many of the early techniques are now covered on the encoding and output page, itself still a work in progress as more details emerge. As part of this endeavour, Micro Switch KB encoding switches are now detailed on their own page; these pre-date the reed switches by a couple of years or so, something still in line for documenting according to literature.

Other discoveries made in 2020 include:

All things considered, 2020 has fared significantly better than it could have, and with luck 2021 will be at least as bountiful.

View within the updates for 2021

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