In the coarse of my work on B3603 alternative firmware project I needed to understand how to drive different pins and experiment with it. Thinking about something, coding it, loading and testing is just too cumbersome and slow so I wrote a firmware that will only allow driving the pins, both input and output. This enables immediate experiments on different items such as:
* How to drive the leds
* How the 7-segment display is driven.
* How to work out the buttons