IBM 5251 Keyboard

By Xah Lee. Date: . Last updated: .

Year 1977

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IBM 5251 keyboard (photo date 2017-11-11)

IBM 5250 is a family of block-oriented terminals originally introduced with the IBM System/34 midrange computer systems in 1977.[2] It also connects to the later System/36, System/38, and AS/400 and System i systems, and to IBM Power Systems systems running IBM i.

5250 devices can be directly attached to the host or communicate remotely using Synchronous Data Link Control (SDLC) at up to 9600bit/s. Devices can also be clustered or daisy-chained.

In 1978 the 5250 system consisted of the following components:[3]

2017-11-12 Wikipedia [ IBM 5250 ] [ 2017-11-12 ]

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IBM 5251 keyboard (photo #32502 date 2017-11-11)
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IBM 5251 keyboard (photo #34689 date 2017-11-11)

IBM Beam Spring Switch

This uses a “beam spring” as its key tactile mechanism, and uses capacitance as electric switch.

a “beam spring”, is basically just a bent strip of metal, function as a spring.

beam spring switch 12709
beam spring switch [image source]

A beam spring switch uses beam spring as tactile mechanism. When enough pressure is forced, it bents the other way, and activates the electric switch mechanism.

IBM 5251 Keyboard review (beamspring)
Sep 2, 2017


IBM 5250 Information Display System Manual

keyboard at page 26.

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