Arduino Shield For PORTA Input
From the blog "Out of the Pack"
Over the years I've been using an Arduino UNO to setup data for transfer to the Atari Joystick ports. The first attempt was to read the data from a Wii nunchuk and translate it to joystick movements. Lately I've been experimenting reading midi data using an Arduino Midi Shield, along with using the Cassette Motor Control pin on the SIO port as feedback to the Arduino. You may have read some of these blogs.
During the "Switched On POKEY" music experiments, there were many modificat