Atari ST

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The Atari ST was a series of computers from Atari. "ST" stood for "SixTeen", referring to its Motorola 68000 CPU having a 16-bit data bus. "Mega ST", "STm", "STfm" and "STe" noted different hardware variations. The Atari TT (ThirtyTwo) and Atari Falcon had 32-bit data buses.

It was especially popular among musicians because all models included also MIDI in and out as standard.

Interface

Keyboards use a Atari-specific serial protocol at 7812.5 Baud (500 KHz ÷ 64).

The mouse is a bus mouse that connects to the first of two DE-9 ports on the keyboard. Both ports can be used for Atari-compatible joysticks. There are however only two buttons in total: the joystick buttons of ports 0 and 1 are wired to the left and right mouse buttons respectively.

The keyboard controller also has a realtime clock with one-second accuracy.<ref name="astinternals">K. Gerits, L. Englisch, R. Bruckmann — Atari ST Internals, 3d Edition. 1988. ISBN 0-916439-46-1</ref>

Integrated keyboards also have Power and FDD disk activity LEDs.

Variations

Silitek

Silitek dome with slider: slider over individual rubber domes with conductive rubber on PCB. Silitek as an OEM is not confirmed, but the keyboards match Silitek's patented switch design.

The keycap mount is a cruciform mount. It is slightly bigger than Cherry MX making it incompatible. Keycaps are double-shot light grey with brown letters, or on the Atari Falcon: dark grey with light letters. Most keys have cylindrical profile except for the backwards-L Return key which has a spherical profile.

The key feel is very mushy (at least today) and the keys are wider than standard (which can impair typing accuracy).

Confirmed to be integrated within the Atari ST FM,<ref>Atari-Forum — [PICS] Keyboard LED replacement</ref> and Atari STe but also reported to be the type found in the Atari 520 ST, 1040 ST, STF, STFM and Falcon.<ref>eBay — Atari 520 1040 ST STF STFM STE Falcon keyboard Letter Plunger And Connector ^{[Volatile reference]}</ref> In integrated computer cases the case screws can be identified by being in square holes where as other screws are in circular holes.

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  PCB and barrel plate separated
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  Back of keyboard (after reassembly)
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  Looks like a variation of Silitek dome with slider, doesn't it?
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  Barrel plate. Resting on its keys, still snapped onto keys.
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  Key profile. Swedish layout with split left Shift.
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  Inspection label and closeup of the Return key
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  Mouse and joystick ports on bottom of integrated keyboard. The computer has to be lifted to access them.

Mitsumi

The Mega STE has been found with a Mitsumi KPQ Type keyboard.<ref>AtariAge Forums — My Mega STE restoration......or just clean up ?</ref>

Cherry

There is a stand-alone variant with Cherry MX Black switches.<ref>Flickr: HaaTa's collection — Atari ATW800 US. Retrieved 2018-06-03</ref> It was shipped with the Mega ST.<ref>WUDSN — Revision 2017 - Atari Mega ST</ref> The keys are in the same brown-on-gray doubleshot style as for the more common Silitek variant but with different cruciform mounts for switch and stabilisers.<ref>Geekhack—Inside an Atari MegaST keyboard. Dated 2019-02-05. Retrieved 2019-02-06</ref>

See also

• Commodore Amiga — The Atari ST's main competitor
• Atari interface — The interface used for mouse and joysticks

References

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