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Micro Switch RW Series

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Overview

RW Series is a series of reed switch keyboards from Micro Switch, which use Series KB switches. These keyboards are so far known only from 1970, although customer-produced keyboards using Series KB switches date back to around 1966–1968. It appears that the use of these switches in keyboards was fairly short-lived, with Micro Switch instead pushing SW Series solid state keyboards that were introduced in 1968.

Via his son Scott, Everett Vorthmann from Micro Switch has indicated that “RW” denotes wired reed keyboards, i.e. fully-assembled keyboard units with reed switches.

Series KB switches could be soldered to printed circuit board, hand-wired onto notched terminals, or connected via spade connectors. Third-party keyboards tended to use spade connectors and hand-wiring, while Micro Switch RW keyboards appear to all use PCB assembly. As with all Series KB–based keyboards, the switches are attached to mounting rails.

RW Series keyboards so far have been found to use 2SW Series keycaps (or a derivative thereof), with extra notches added to accept special wide keystem adapters.

Electronic Engineer magazine’s this is your keyboard reference from 1971—jointly a Micro Switch advertisement—depicts reed and solid state keyboards together, but does not name the series of either.

Keyboards

Keyboard Switches Date Notes
Potter Instrument KDR/KB 3100A Model 12 (51RW1-2) 7A1MT 7005
K50164-57RW ? 7014 Completely non-standard catalogue listing number
57RW1-2 chassis 7A1MS 7035
53RW4-1 chassis 7A1M-X14 7044

Components

Part Description
RW-10038 8-to-4 binary encoder (DIP-16)
RW-10039 7-to-4 binary encoder (DIP-16)

RW-10038 and RW-10039 can be seen in the keyboard circuit diagram for the Mini Bee computer, as shown in the Mini Bee Computer Terminal Service Manual, with what appear to be fabricator part numbers WC 513 D and WC-514 D. Micro Switch 64SW1-4 has a similar if not identical circuit, and in this example, these two ICs were fabricated by Motorola and bear only Micro Switch’s part numbers. Both of these examples are SW Series Hall effect with two-of-N encoding, where these chips (two of each) provide the scancode conversion.

See also