Original specs/details

Full Name Lexmark Classic Touch Keyboard with Integrated 25mm Trackball
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 M5-2 Trackball Keyboard
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 protocol(s) this keyboard can use to speak to the host computer (eg, scancode sets).
IBM Mode 2 (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 dual mini-DIN PS/2 cable
Form FactorForm Factor
The standardised or universally acknowledged name for this keyboard's layout form factor.
Built-In MouseBuilt-In Mouse
Possible pointing devices this keyboard could carry. This could be a brand name, name of the sensor technology behind it, or a generic description in lieu of the former details.
25mm trackball
Production Date 1993-12-14
Acquisition Date 2019-12-26

About this keyboard type

The Model M5-2 is one of two variants of the Enhanced Keyboard featuring an integrated trackball pointing device attachment, along with the M5-1. The M5-2 uses a 25mm trackball placed on the top-left corner of the keyboard case and features eight mouse buttons; two for left and right click and two for left and right stepped-click, with both pairs repeated on the back-side of the trackball module. Unlike the M5-1, the M5-2 has remained in production and continues to be produced by Unicomp as the Unicomp Classic Trackball Keyboard (also previously called "On-The-Ball"). Collectively, the M5s were the last introduced Model M variants to feature a modular SDL connection. However, Unicomp has since moved the M5-2 to a fixed cable design.