IBM/Unicomp Model M keyboard matrix simulators and 2KRO visualisers!

Hello there!

In the 3 years or so I’ve been in this hobby, I’ve noticed that (to no fault of any particular person) how the IBM Model M’s membrane key-matrix operates and what two-key rollover (2KRO) means can be misunderstood. Combined with many questions people have regarding Unicomp Mini Model M’s improved key combination support, I decided to make some visualisations to help people:

  • Understand what 2KRO means for Model Ms and how for them it doesn’t necessarily mean 3+ key combinations don’t work.
  • Test possible key combinations to see if they work before any purchase. People wondering if their gaming key combinations would work on a Model M is pretty common.
  • See how Unicomp changed what sort of key combinations can work via their newly designed matrix for the Mini M.

Find them at: Admiral Shark’s Keyboards - Media#Simulators

The debut simulators include:

  • IBM Enhanced Keyboard (101/102-key, applies to Lexmark versions)
  • IBM Space Saving Keyboard (84/84-key, applies to Lexmark versions)
  • Unicomp PC 122 (Type IV 122-key with late-style controller)
  • Unicomp EnduraPro or Ultra Classic (104/105-key)
  • Unicomp Mini Model M (87/88-key)

Each simulator sports an interactive keyboard, the ability to switch between ANSI US English and ISO UK English layouts (or 3270 and 5250 compatible layouts for any 122-key simulators), the ability to show colour-coded matrix columns or rows on said keyboard, and a tabular view of the raw matrix itself.

Matrix column visualisation

Matrix row visualisation

Regarding the Unicomp Mini M specifically, the simulator shows you how Unicomp managed to make the entire physical home row and/or WASD operable with each other despite the keyboard still being membrane-driven/2KRO - each key on the home row or WASD was wired to have its own matrix column!

purdeaandrei - the GOAT - was instrumental in helping make this possible by providing matrices and looking over my code! Note that this is still technically W.I.P. with some improvements still planned:

  • More colour keys, such as for possible interface (like USB) limitations.
  • Mobile/tablet optimisation.
  • More layouts to suit the majority of possible site viewers - the shortlist includes Arabic, Brazilian Portuguese (ABNT2), Canadian French, French, German, Italian, Portuguese, Latin American Spanish, and Spanish.
  • Of course, more keyboards including buckling sleeve Model Ms.

Please let me know what you think!