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NAVCOR

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.

Contents

Patents

Patent Title Filed Published Product
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

Keyboards

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

Series 1050, also Model 1050 and simply 1050, is a seris of standalone reed switch keyboards. 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 appears to be the standard full-size keyboard, and model 1050N is a 16-key numeric keypad.

An advertisement in Information Display in 1968 (volume 5 no. 5, September/October) entitled “Electronic Keyboards” reads:

Navigation Computer Corp., Norristown, Pa., manufactures the NAVCOR 1050 series keyboard assemblies. Completely modular in construction, the keyboards are available in a wide variety of standard configurations. Signals from the keys can be either brought out directly or coded to user requirements by a diode matrix. Standard keyboard configurations include alphanumeric models with up to 65 keys and numeric models with up to 16 keys.

Model 1051

Model 1051-C is the PCB inscription of a Raytheon DIDS-400 terminal keyboard manufactured by NAVCOR. A damaged copy of a Raytheon DIDS-400 brochure depicts the complete unit. The switches are the type depicted in US patent 3251962 and appear to be KRM type based on the limited depiction of the KRM switches in the magazine article on Model 1067. The single known example appears to date from 1967, based on the single IC present. This example is diode matrix encoded, and appears to have resistance-based electronic interlocking.

A nearly identical keyboard, stated by Raytheon to be Navcor 1051D-14B, can be seen in the DIDS-400 Model 402-2M10 service manual, available at Bitsavers under Raytheon DIDS-400. The Raytheon service manual for this latter terminal indicates that the keyboard is straight 6-bit ASCII encoded directly.

1067

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.

Switches

KM Keys

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

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.

Later type

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”.

Examples

The service manual for the Raytheon Model 402-2AM13 Display Terminal (part of the DIDS-400 Digital Information Display System) from August 1968 indicates that the “Keyboard and Matrix” component is NAVCOR part C28490. This is a reed switch keyboard with diode matrix encoding. No further details are given about the keyboard implementation. Raytheon had already introduced their own keyboard switches by December 1967.

Documentation

The following documentation was all scanned by Bitsavers.