Talks - Jeff Epler: Connecting Old to New with CircuitPython: Retrocomputer input devices on...

CircuitPython can be used to convert vintage input devices to modern USB HID devices using microcontrollers like the RP2040

Three main projects demonstrated: converting a Commodore keyboard, Tandy keyboard, and NeXT computer bus mouse to USB

Key matrix keyboards use a grid arrangement of switches, allowing many keys (64) to be controlled with fewer pins (16)

The RP2040’s PIO (Programmable I/O) feature is crucial for handling timing-sensitive operations that would be too slow in regular CircuitPython code

Non-invasive approach is important when working with vintage hardware - using proper connectors rather than cutting/modifying original equipment

Many vintage computers have active preservation communities that maintain documentation and technical specs online

Some vintage keyboards used unique key switches that are irreplaceable today, making preservation especially important

5V to 3.3V voltage level differences can be managed, though slightly out of spec, with minimal risk to modern components

Quadrature encoding is used in vintage mice to determine movement direction and amount

Open-source documentation, including 3D printable cases and wiring diagrams, makes these conversion projects reproducible by others