|FRU Part NumberFRU Part Number
Field Replaceable Unit
The number used to relate and indicate compatible but otherwise potentially different keyboards that could replace this one.
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 M4 Space Saver Keyboard|
Possible companies responsible for making this keyboard for the company marketing it.
The name of the known switching mechanism that lies under this keyboard's keys.
|IBM buckling rubber sleeves (M3/M4 rod-actuated type)|
|Earliest AppearanceEarliest Appearance
The year (and possibly the quarter) that this keyboard part number was introduced, first observed, first recorded or the first example found.
|Original KeycapsOriginal Keycaps
The keyboard's original keycaps' material and text/symbol printing technique.
|PBT with dye-sublimated legends|
|Casing ColourCasing Colour
The original colour of this keyboard's outer casing. For keyboards whose casing materials are known to yellow, this will refer to the original colour before such transformation occurs.
The possible branding and logo styles found on this keyboard part number. This could be multiple styles at once or possible styles found over time.
|IBM blue oval badge|
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.
|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|
|Key CountKey Count
The number of keys that this keyboard originally had.
|Form FactorForm Factor
The standardised or universally acknowledged name for this keyboard's layout form factor.
The original regional/language layout this keyboard was configured as. Both the language and the standardised key layout may be listed, and in the case of both being known or defined, it will be styled as language then standard.
Documents ("Doc"), websites and/or webpages ("Web") that were used as a source of information for this keyboard part number. Examples of this keyboard part number I own ("ASK") will also be included as sources.
|Data Last Updated||2023-04-21|
More on this type of keyboard...
The IBM Space Saver Keyboard (not to be confused with the IBM Space Saving Keyboard or SSK) was the discrete desktop and server environment adaptation of the IBM Personal System/2 L40SX laptop's Model M3-based buckling sleeves keyboard assembly. The Model M4 is a straight adaptation of that assembly, featuring the same layout but available with beige or black case colour. M4s were originally produced by Lexmark and Key Tronic, however, Unicomp continued selling M4s until 2010. Unicomp's internal codename for the M4 family was "Surf".