Original specs/details

Full Name Bull DPX/20 Keyboard
Part NumberPart Number
The number used to describe this keyboard's specific release; usually specific for a target region, language or SKU, etc.
A designation from my own type naming scheme used to categorise this keyboard with or from others by their common features and market intent but may/may not be derived from official names.
Model M Enhanced Keyboard with Speaker
The name of the known switching mechanism that lies under this keyboard's keys.
IBM membrane buckling springs
Original KeycapsOriginal Keycaps
The keyboard's original keycaps' material and text/symbol printing technique.
PBT with dye-sublimated legends
The style of this keyboard's flip-out or extendable feet. If applicable, this may also state how many levels of height adjustment are available and whether the feet could be rubberised.
Single-setting flip-out feet
The protocol(s) this keyboard can use to speak to the host computer (eg, scancode sets).
IBM scancode set 2
The keyboard-to-host connection. This is could be a description of a cable (its colour, whether its coiled, whether its detachable, and what connector is at its end) or the name of a wireless technology.
Grey coiled-style detachable 6-pin SDL to PS/2 mini-DIN cable
Form FactorForm Factor
The standardised or universally acknowledged name for this keyboard's layout form factor.
Production Date 1995-10-17
Acquisition Date 2022-06-27

About this keyboard type

The Model Ms made for the IBM RT PC and RS/6000 systems were variants of the IBM Enhanced Keyboard featuring an integrated speaker on the underside of the keyboard. The speaker, which occupies a space usually left unfilled on other Enhanced Keyboards, is believed to act as an audible cue when keys as pressed. The speaker is operated by the host system via extra pins in the unique AMP-made connector (RT PC) or the unused pins in a PS/2 plug (RS/6000). For PS/2 variants, the keyboard itself can still be used with standard AT or PS/2 class PCs, however, the speaker cannot be utilised by them without creating an additional circuit to signal the usually unused pins.