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Amkey and Cortron



Amkey was an American keyboard manufacturer located in Massachusetts that specialised in capacitive keyboards. Amkey, Inc. was incorporated on the 16th of April 1975. In 1977 Amkey filed US patent 4163222 “Synchronous phase detected keyboard” for their capacitive detection mechanism. This mechanism is based on the standard construction of a foam pad with foil applied. A later patent US4439647 filed in 1982 covers flat keyboards.

Around 1989, ITW Cortron (the keyboard spin-off from ITW Licon) was sold to Amkey. Amkey, Inc. was dissolved in December 1990. In the Boston Globe on the 2nd of January 1994 it was announced that Amkey and Cortron had merged to form Cortron Inc, although the merger was already announced in the 8th December 1993 issue and the original Amkey had not existed for three years by that time. Evidence of this transition can be seen in the examples below, where model 106-0004 (formerly DIN-106) eventually changed to Cortron branding.

Amkey appear to have specialised in foam pad capacitive keyboards, while the only known capacitive keyboards made by ITW were of the Digitran metal plate design (Cortron CP-4550). After Amkey’s acquisition of Cortron, it’s not clear how the two companies’ product portfolios were merged, but Amkey’s foam pad capacitive approach was the surviving one, with the ferrite core technology appearing to disappear. It is possible that the acquisition brought innovations previously owned by ITW Cortron; there are too few known examples to be able to compare designs from before and after the acquisition. Cortron keyboards post-acquisition are covered here rather than under the ITW Licon/Cortron page.

The present-day Cortron, Inc. only dates back to March 2005, having been initially named ELF Enterprises, Inc. after Eric Friedrichs. ELF Enterprises was renamed to Cortron, Inc. a year later in March 2006. The previous Cortron was founded in Massachusetts on the 1st of May 1989, and merged with Friedrichs Enterprises in October 1993. This 1989 business dates from when Cortron moved from Illinois to Massachusetts following the acquisition by Massachusetts-based Amkey. On the same day that ELF Enterprises became the new Cortron in 2006, the old Cortron was renamed to W. F. Enterprises, Inc., where “W. F.” denotes Wayne L Friedrichs.

Cortron’s own website indicates that the business was founded in 1969, which is misleading at best. This year corresponds with the first keyboard patents filed by ITW on behalf of ITW Licon, and this is possibly what Cortron consider to be their starting point. ITW itself was formed in 1912, and ITW Licon in 1959 according to a history of Illinois Tool Works Inc. at FundingUniverse. ITW Switches however gave 1954 as the year that ITW Licon was formed, in their 2009 product catalogue. (Licon may have only existed as a division, which is possibly why the company itself cannot be traced.) ITW Cortron advertisements suggest that the Cortron division of ITW dates from 1976; these advertisements also indicate that Licon’s inductive keyboards were announced in 1968, although no evidence prior to 1968 has been identified.

Cortron themselves have consistently refused to provide any information on their company history.


There is presently no known surviving information on Amkey series. Many keyboards use model prefixes such as “MNK”, “SNK”, “MPNK” or “DIN”. The DIN models appear to all be DIN-compliant foam pad capacitive. The “S” in “SNK” likely denotes “solid state”, while the “M” in “MNK” could indicate a mechanical model. “MNK” is only known from MNK-4, a model with no mounting plate for the switches that looks suspiciously mechanical. “MPNK” models also appear to be foam pad capacitive, not mechanical.

Advertised models

Model Type Source
PRO 100™ Solid-state capacitive, 99-key enclosed keyboard for Apple ][ and ][+ Ads: Hardware 1983 (apple2history.org)
MPNK-100 Depicted as a module; 5-mode Computer Design 1980
MPNK-72 Replacement for Key Tronic L1660; rated life in excess of 100 million mean cycles before failure (MCBF); listed as both “capacitive” and “contact key switch” Computer Design 1981
DIN-64 Solid-state capacitive, DIN-compliant, depicted as a module EEM 1991
DIN 106-1 Solid-state capacitive, DIN-compliant, depicted enclosed (105-key) EEM 1991
DIN 124 Solid-state capacitive, DIN-compliant, depicted enclosed EEM 1991
MPNK 101 Depicted as a module EEM 1991
MPNK 114 Depicted as a module EEM 1991
SNK 16 RS-232C 16-key keypad with N-key rollover, depicted as a module EEM 1991


All the examples below are foam pad capacitive unless stated otherwise.

Model Manufacturer Keys Mfr. serial Date Equipment Notes Reference
MNK-4 Amkey 62 ≤ 1976 Possibly a mechanical model; there is no mounting plate for the switches; used with the Apple I prototype Apple-1 Registry
SNK-58 Amkey 58 75254 June 1982 T-Bar brand serial test equipment? Deskthority
MPNK-106 Amkey 97 77435 October 1982 Computek The keycaps appear to be Comptec SA family Flickr
MPNK-68 Amkey 68 100648 Circa 1985 Computervision Corporation Just another electronics blog
DIN-106 Amkey 84 111156 10/87 eBay
MPTK 129 Amkey 129 113837 Circa 1988 Reported to be from a B-52 Stratofortress This appears to use adapters to fit Amkey keycaps to Micro Switch mount keystems, but this cannot be determined from simply the photographs available geekhack
106-1004 Amkey 84 114339 12-88 Identical to DIN-106 Premier Equipment Solutions
106-0004 Amkey 84 118107 1990-08-16 Identical to DIN-106 eBay
106-0004 Amkey 84 122680 5/93 Identical to DIN-106 eBay
106-0004 Cortron 84 C54493 8/98 Identical to DIN-106 eBay
106-0004 Cortron 84 C61931 5/99 Identical to DIN-106 eBay
106-0141 Cortron 105 C71043 3/01 First known use of non-stepped keycaps; new plastic plungers and new keycap typeface eBay
Model-80 (604-0003) Cortron 82 C117761 2809 The switches are sealed with a clear plastic sheet; same switches and keycaps as 106-0141 Deskthority


All literature below was scanned by Bitsavers.