Adding legacy: The AVON I/O Driver Board was designed to be piggybacked by the U-HID microcontroller (by Ultimarc).
– 19 outputs (logic-level MOSFETs or the like)
– 28 inputs (from switches etc.)
– Pull-down resistors on all outputs
– Zener diodes to protect back-voltage (never 100% safe)
– LED on each channel for determing if an output is high
This board has been discontinued.
Used on the game Astro Attack!