Bit One MIDI Upgrade Kit
Addresses several of the Bit One keyboard's more irritating shortcomings - allows you to: use both the keyboard and external MIDI at the same time; set and remember the MIDI channel on the synth itself; receive MIDI pitch bend, mod wheel, and sustain pedal.
Also adds a vintage-inspired arpeggiator, with up, down, up + down and random modes. Requires an external MIDI clock source such as a drum machine.
As it also pre-filters MIDI data before it goes to the synth's own CPU, MIDI response is a lot more reliable - the stock synth is very prone to lock-ups and stuck notes when receiving a lot of MIDI data.
it includes pre-assembled MIDI board with ribbon cable, DIN socket, chip socket and mounting hardware.
Installation & user instructions can be found here -
Note that it isn't currently compatible with the new Tauntek replacement firmware for the Bit One, but this is something I plan on adding support for.