The Navigation Computer Corporation, later NAVCOR, Inc. and as KDI Navcor, Inc., was an American electronics manufacturer. Their output included reed switches and reed switch–based keyboards.
|US 3244847||Manually operated keyboard switch in a stationary mount with guided shaftway||1964-05-22||1966-04-05||Mechanical keyboard switches|
|US 3233061||Magnetically detented keyboard switch||1964-10-05||1966-02-01||Unidentified reed switch type|
|US 3251962||Precision magnetic keyboard switch||1965-05-17||1966-05-17||KM Keys reed switches|
|US 3456077||High speed electronic keyboard assembly||1965-09-22||1969-07-15||Keyboard encoding circuitry|
|US 3311210||Sloping panel keyboard mount||1965-10-12||1967-03-28||Slanted base for keyboard switches|
|US 3664014||Universal modular printed circuit magnetic reed keyboard switch assembly||1969-08-14||1972-05-23||KRM reed switches|
|US 3594487||Contactless electronic keyboard array||1969-08-25||1971-07-20||Switchable transformer contactless keyboard|
|US 3601728||Printed circuit key improvement||1969-10-03||1971-08-24||Later style reed switches|
Series 1010 Tapewriter
The Series 1010 Tapewriter is a tape punch unit with an integrated keyboard. Advertised in 1963, it is not clear what switch type these machines use: the article describes it as having “a single gold-plated, etched-circuit board for the mounting of precious-metal wiping contacts that are activated by magnetic keys”. Encoding is provided by a diode matrix.
Series 1050, also Model 1050 and simply 1050, is a standalone keyboard with reed switches. The earliest known advertisement for Series 1050 is from March 1963, in Computers and Automation, where it is implied to be newly introduced. 1050 Series is included in the article Manual Input Devices in Computer Design magazine in December 1965 (CD1965-MID); a NAVCOR advertisement in this magazine issue covers both 1050 and KM Keys reed switches, with the possible suggestion that KM Keys are used in the 1050. An optional diode matrix board can be fitted for character encoding, with up to 15 output bits per key. Model 1050 is the full-size keyboard, and model 1050N is a 16-key numeric keypad.
Model 1067 uses KRM switches. Instead of a diode matrix, output generation utilises wired inductive encoding. The magazine article in Electronics that describes and depicts this model was published in June 1968, a little ahead of the filing date of the patent for Licon Series 550. As such, it is not clear which company arrived at the idea first. Licon keyboards made the ferrite cores a part of the switching mechanism, while NAVCOR only used them for encoding. Where Licon used flying leads for the magnetic encoding, NAVCOR ran PCB tracks through the cores. The sole photograph of the internals of this model do not fully or clearly depict the encoding arrangement. The reason given for moving to inductive encoding is the concern that using 225 diodes would be too costly and too unreliable.
The comparator circuitry allows up to two keys to be pressed at once; the keyboard is locked out when three keys are held at once. The reasoning for this is not given, and it seems confusing, as the output should become invalid even with two keys simultaneously active. Current draw measurement is used in order to determine the number of active keys.
An optional “attachment” generates click feedback; it is not stated whether this is per-switch or a single feedback unit for the whole keyboard; the wording does imply the latter.
KM Keys is Navcor’s older reed switch type, with a cylindrical shell. These are rated to 100 million operations, and were offered in “switch closure or pulse outputs” and have a “magnetic hysteresis band [that] prevents make/break microphonics.” KM Keys were advertised in Computer Design magazine in December 1965 (CD1965-MID). US patent 3251962 filed in May 1965 covers this series.
KRM is a series of reed switch with an internal PCB to which the reed capsule is attached. US patent 3664014 filed in August 1969 with an earlier priority date of October 1967 covers this design. KRM switches were used in the model 1067 keyboard. Up to four reed capsules are supported, although on each side of the switch the reed capsules share a single common terminal. The switches are fitted with a sloped base. The rated lifetime of the switches is 100 million cycles.
The designation of these switches is unknown. They are simply described as “Navcor magnetic reed” on the Deskthority wiki. This later design is depicted in US patent 3601728 filed in October 1969. Unlike KRM, there is no printed circuit board holding the reed capsule. Alternate action is supported. According to the Deskthority wiki, these switches are only known from some unspecified “Teletype replacement keyboard”.
The following documentation was all scanned by Bitsavers.
- Series 1050 keyboards advertisement, Computers and Automation, March 1965, page 50
- Series 1010 advertisement, Electronics, December 13 1963, page 58
- NAVCOR 1050 advertisement, Electronics, December 26 1966, page 39
- Keyboard with Ascii output costs $500 (model 1067), Electronics, June 10 1968, pages 201–204
- NAVCOR advertisement, Computer Design, March 1969, pages 6-7
- KDI Navcor Time Tested Keyboards, Computer Design, March 1970, page 127
- KDI Navcor Time Tested Keyboards, Modern Data, March 1970, page 13