IBM Personal Computer keyboard

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IBM Personal Computer keyboard
IBM XT top.JPG
Model no. IBM PC 5150 keyboard
FCC ID N/A
Manufacturer IBM
Product family IBM Model F
Layouts IBM PC Computer keyboard
Keyswitches IBM capacitive buckling spring
Interface 5-pin DIN XT
Dimensions 19.6 × 7.87 × 2.2 inches
(500 × 200 × 57 mm)[1]
Weight 6.5 lb (2.9 Kg)

The keyboard of the 1981 IBM PC 5150 is commonly referred to as the "PC XT" keyboard, although it pre-dates the XT. It was based on the Datamaster keyboard, but was mounted in an external case and used a unidirectional serial connection with a DIN-5 connector. When the PC was released, the keyboard was acclaimed for its touch, but its layout was criticized for having many oddly shaped keys placed close to each other.

Known variants

  • 1501100 (US English layout)
  • 1501101 (French AZERTY layout)[2]
  • 1501102 (German layout)
  • 1501104 (Italian layout)
  • 1501105 (UK layout)

Keycaps

The keycaps are made from PBT and are popular for their high quality dye sublimated legends. Other than most modern IBM buckling spring keycaps, these keycaps consist of a single, solid part and do not have the removable covers common on IBM Enhanced Keyboards. The keycaps are compatible with other IBM Model F keyboards and IBM Model M keyboards of the first generation.

Known issues

The IBM Personal Computer keyboard has a 10-unit space bar that cannot be removed without disassembly of the keyboard. While all other keycaps can simply be pulled off, the space bar will likely get permanently damaged in an attempt to pull it off. In order to remove it, the case must be opened and the barrel plate must be separated from the bottom plate/PCB. Only then can the stabilizer wire of the space bar be un-hooked which allows the space bar to be pulled off like any other key.

The space bar is also known for being significantly stiffer than all other keys of the keyboard. It is the only stabilized key and has a much increased stiffness due to the design of the stabilizer wire. There are guides explaining how to soften the space bar by bending the stabilizer wire in a certain way.

Types

The earliest of IBM Personal Computer keyboards were slightly different than the more common version of the keyboard. In fact, the IBM PC XT Technical Reference manual published in 1983 lists two different types of IBM Personal Computer keyboards identified as Type 1 and Type 2. The one most commonly found is the Type 2 keyboard because it was manufactured early in the product life cycle for the IBM Model 5150 PC and used throughout including the product life cycle for the IBM Model 5160 PC XT.

The Type 1 keyboard is constructed with different internal electronics; including an extra activated pin for RESET in the normal 5 pin DIN cable. The Type 2 keyboard has that pin but it is not internally connected so the later keyboard performs a keyboard reset internally when powered on. While there is this difference, both use IBM’s XT protocol for communication.

While the Type 1 keyboard appears to always have a metal keyboard connector that mates with the IBM PC, not all IBM Personal Computer keyboards with a metal connector are Type 1. The only true way of determining if an IBM Personal Computer keyboard is Type 1 is by opening it and checking for the elongated internal PCB with the extra electronics.

USB conversion

Using this keyboard with a modern PC over USB is relatively simple. An Atmega32U4 development board flashed with Soarer's Converter is required. Please consult the forum thread about Soarer's Converter for wiring/soldering advice.

Gallery

IBM Personal Computer Type 1 keyboard:

IBM Personal Computer Type 2 keyboard:

Type 1 versus Type 2 IBM PC keyboards

References

  1. Personal Computer XT Hardware Reference Library: Technical Reference. Appendix E: Specifications, p. E-1.
  2. Deskthority — (Help) Price Check: How much is my _____ worth?