This interactive tool simulates the key-matrix of a IBM Space Saving Keyboard so that you can test if possible key combinations work without needing to test on a physical keyboard. Model M keyboards are all fundamentally two-key rollover (2KRO) due to the use of a membrane assembly, but this doesn't mean Model Ms cannot register more than 2 keys unlike popular belief. This tool demonstrates this and can allow you to see if a given Model M key-matrix would be suitable for your needs.
Disclaimer & notes
This tool is intended to be a guideline only. The results from any input are based on physical key-matrix data only and doesn't take into account firmware (ie, differing deghosting algorithm implementations or bugs/quirks). If you're using this tool as part of a purchasing decision, if possible, it would be prudent to try verifying results on a real keyboard someone you know has or ask on /r/modelm subreddit. The tool is also best viewed on desktop.
Only UK English functional layout is available for the ISO simulator at this time
|Firmware caution: A 3-key combination that may or may not be problematic depending on keyboard's firmware. A custom QMK-based controller would probably be fine with these, but IBM/Lexmark/Unicomp native firmware may not.|
|Hardware block: A N-key combination that will block in any circumstance due to the matrix's design. There is nothing you can do about these since they're a fundamental key-matrix limitation.|
This is a tabular representation of the data used by the simulator above. A keyboard matrix is constructed from a series of columns (X-axis) and rows (Y-axis) whose intersections are used for key assignment. Such matrices allows a large number of keys to be driven by relatively few traces, as opposed to each key requiring its own circuit.
- Many thanks to Purdea Andrei (/u/_pandrew, purdeaandrei) for providing the IBM Enhanced Keyboard, Unicomp PC 122, Unicomp EnduraPro/Ultra Classic and Unicomp Mini Model M matrices and providing technical assistance.
- Many thanks to whiskerbiskit for helping to crack the Unicomp Mini Model M matrix.
- phosphorglow's IBM Space Saving Keyboard matrix was used for the IBM Space Saving Keyboard matrix simulator.