KBK update for Sunday, 11th July

Another day, another coincidence. Having only just documented the Harris HD-0165 16-to-4–line binary encoder and the intention that these would be used in pairs for keyboards, a Zbrojovka Brno keyboard appears in eBay’s suggestions box that works in pretty much the same manner. The Consul 259.13 keyboards uses a pair of TESLA MH1KK1 16-to-4–line binary encoders in conjunction with Hall effect switches. Instead of defining the output in the switch wiring, a single Fujitsu 1 kB PROM appears to contain the output codes. (There appears to be only one, but not all the chips can be clearly seen.)

The starting point for this was an eBay listing for an IBM 5576-002 keyboard, in its original box. The Alps model number is printed on the box: KFCREA087A. This model number reveals the existence of another Alps series: SKCR switches and KFCR keyboards. So what is SKCR? With the IBM 5576-002 keyboards only known to use Alps “plate spring” switches, one could take a reasonable bet that, since we know that Alps KCP/SKCP is the plate-mount “plate spring” type, then Alps SKCR would be the square PCB-mount “plate spring” type. (There is a second PCB-mount type to find an identity for.) Frustratingly there is insufficient data at present to indicate whether SKCR began life as KCR; there does not appear to be a separate utility model for either of the PCB-mount types. For now, “SKCR” is being used in accordance with the only available data.

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