FR Electronics was a subsidiary of Flight Refuelling Ltd (now Cobham plc) that produced electronic components. This included reed keyboard switches. Cobham no longer have any record of these switches. Switch production was moved to RRE (Reed Relays and Electronics India Limited), a joint venture with FR Electronics that lasted for 20 years until FR Electronics left the market. RRE were able to supply some old stock illuminated switches (which they called RKS 80-1AL instead of RSM82-1AL) but they too have no details left on this product range.
The following products relate to keyboards:
- RSM reed keyboard switches (RSM 60, RSM62, RSM82, RSM83 …)
- Keyboards and keypads
Only one keyboard has ever been found with these switches, a 1988 Plessey Displays keyboard. The photos for this are all lost now, so it can no longer be examined for clues.
FR themselves supplied a hexadecimal-encoded 16-position keypad, model KB44E, with RSM82 switches. Advertisments from 1978 and 1979 partially visible on Google Books indicate that it was “very low profile” with TTL-compatible parallel BCD output, and accepted a 5 V supply (or, depending on what you read, between 3 V and 15 V). Two-key rollover was included, provided by CMOS encoding circuitry.