I’ve been getting into PCB design and electronics recently, here is where you will find documentation and links to all the hardware I’ve made or contributed to in some way.

A small board to swap out the Atari 8bit OS chip with a larger one that has 4 choosable OS's on it.
A couple of small PCB's that interface Arcade Joysticks and up to three Fire buttons + two pinball flippers to the Atari 8-bit and VCS
The Multijoy is a device to allow you to plug up to 16 joysticks into an Atari 8-bit computer with just 2 joystick ports.
Small PCB that allows an SDrive-MAX to coexist on the SIO bus with other devices.