This is a simple speaker and switch demo board, designed for writing code that outputs a square wave to the speaker with a frequency determined by the input of the switches. The purpose of this board is to test the I/O capabilities of kit and/or retro computers, such as the KIM-1 and RC2014.
There are currently three versions of the board available.
- Version 1 is adapted straight from the KIM-1 manual. The switches toggled between floating and GND. This works for machines that pull up their input pins.
- Version 2 is just like Version 1 except the switches toggle between 5v and GND.
- Version 3 is the most advanced of the boards. It adds resistors to prevent accidently grounding output pins and a flip-flop which buffers the output signal.
This listing is for the bare PCB only. All images of assembled boards are for reference only. A Bill of Materials is available here or a parts kit is available for purchase separately.