Jump to page content

Applied Dynamics International



Applied Dynamics International (ADI) is a US business founded in 1957. During over 60 years of history, their product range has included analogue and digital computers and photoelectric encoder keyboards. Keyboards were added to their portfolio upon the acquisition of Collimation, Inc. somewhere around 1975 to 1977; the Collimation name was dropped by 1977.

Applied Dynamics should not be confused with Advanced Datum Information Corporation of Taiwan, who also traded as ADI and produced inductive keyboards.


The limited amount of information in existence about Collimation keyboards makes it difficult to understand which aspects of the product range existed before the acquisition by ADI. Even the available information on ADI keyboards is limited and unclear, and there are no indications that ADI ever filed a single patent.


The following general specifications were given in ADI’s Electronic Design Gold Book 1977/78 advertisement and applied to both D40 and D52 series photoelectric encoder keyboards:

Key pressure 2.0±0.5 oz (equiv. 57±14 g)
Travel 0.195″ (equiv. 4.95 mm)
Pretravel 0.150″ (equiv. 3.81 mm)
Rated lifetime 100 million operations

The keyboards run from a 5 V supply. Power consumption is given as 250 mA for “Basic” (D40, without logic) and 550 mA for “Std” (D52, with logic) keyboards.

The subsequent 1978/79 Gold Book advertisement provides more detailed specifications, which collectively cover both Series 52 optical switching and Series 55 contact switching keyboards. This results in the following additional specifications that are suggested to apply to both types even though this seems unlikely to be true for all of them:

Space bar pressure 4±1.0 oz (equiv. 113±28 g)
Release point 0.060″ (equiv. 1.5 mm)
Switch feedback Audible
Contact life 30 million operations

D40 Series

D40 Series comprises keyboards without logic circuitry. D40 keyboards are described as ASCII encoded with an LED light source. They provide positive logic, TTL-compatible 13-bit parallel output, with “rollover/lockout coding”. Output will be single mode only as there is no circuitry to handle additional modes. The modifier keys are popssibly exposed directly on the 17-pin plug for the host to handle. Double-shot keycaps were provided.

The Electronic Design Gold Book 1977/78 advertisement notes curiously that “each keyswitch contains the coding for lockout and rollover protection.” The advertisement also notes:

Each key has access to fourteen (14) data bits plus a strobe bit. This technique places all of the encoding information in the individual keyswitch, making the code generation independent of the location of the keyswitch.

Sufficient bits are available to encode more than 1000 keys while eliminating the possibility of any erroneous codes resulting from simultaneous depression of two or more keys. The standard keyswitch code structure provides for a final multi-mode code of up to eight data bits with additional bits available.

In the 1978/79 Gold Book advertisement, ADI provided a little more clarification:

Up to fourteen data bits, plus a strobe signal, are available from the photodetectors. This is sufficient to provide a final output code of up to ten data bits and still allow each key to be so uniquely encoded that full or partial depression of any combination of code generating keys will not duplicate the code of a single key. This allows straightforward Implementation of n-key lockout, 2-key rollover, and any necessary code conversion by either software or hardwired logic.

Presently there is no detailed information to indicate how the rollover/lockout encoding worked. Only one such keyboard (a Collimation D40.592) has ever been examined, and of that only three shutters were fully depicted.

D52 Series

D52 Series keyboards are D40 Series keyboards with the addition of a logic board to handle enhanced and custom output. Quad mode ASCII was provided as standard, with the option of fully custom encoding using a PROM. Additional features included negative logic, shift lock, parity generation, auto-repeat and serial output.

Series 5000

Little is known about Series 5000. Identical advertisements for Series 5000 have been found from July and October 1977 and January 1978. D40 and D52 Series were limited to 10 rows of keys and 30 keys per row, or 300 keys total; somewhat contradictively, there were “Sufficient bits are available to encode more than 1000 keys”. (This figure is the number of possible output codes that be specified, but not all of them can be used in the same keyboard at the same time.)

The Series 5000 advertisement depicts a Collimation D40.592 keyboard from the Compucolor 8001 system, even though that is a D40 Series keyboard. The advertisement offers new limits: up to 360 keys (up from 300) and 11 bit output codes (up from 10-bit). The design offers logical or non-logical pairing, indicating that onboard logic is supplied, which was not the case with D40; possibly D40 and D52 were combined into Series 5000, but there is not enough information at present to be clear on the relationship between Series 5000 and the preceding series.

Series 52

The Series 5000 name seems to have been short-lived. Photoelectric models were advertised later on in 1978 under the Series 52 name, which ties in with the older D52 Series. Series 52 had new limits again: a maximum of 233 keys per keyboard (with no indication of the derivation of such an odd number) and 210 final output codes (being 1024, assuming that an all-zeroes key can be registered).

Series 55

Series 55 keyboards used “multi bifurcated contacts”. Little further information exists. When advertised in 1978, this is the keyboard type that ADI were recommending for quantity orders (100 or more units), with Series 52 suited more to prototyping, for secure, rugged and advertise environments and low-quantity custom orders. It seems that these keyboards offered click feedback, even if the Series 52 keyboards did not (the specifications were not clearly written).


All literature was collected by Marcin Wichary from unspecified sources, unless otherwise noted.