Terpstra Generalized MIDI Keyboard

Typical key and channel assignments for playing music with 55 discrete notes per octave.
MIDI CHANNELS
MIDI NOTES
 

FLEXIBLE AND POWERFUL // Key parameters such as max/min position, velocity curves, key note, key channel, and button behaviour can be programmed via SYSEX for each key. A PC-based key-programming utility comes with the product.

Any software that can send customizable SYSEX commands can be used, such as Apple's Logic Pro.

A full microtonal Logic Pro environment using Logic grand-piano samples is available.

Manuel Op De Coul's free SCALA program will play microtonal notes on inexpensive PC-based hardware.