[Ladyada] and [pt] had an old keyboard from NeXT, but since it used a custom protocol it wasn’t usable with modern hardware. So they built a custom device to convert the NeXT protocol to USB.

Typing comfortably on a Smart Phone is best done using an ... [cy384]’s goal was to adapt the PPK as a generic USB HID keyboard using an Arduino Pro Mini clone, with a 3D printed adapter ...