Bizcardtro chiptune PCB business card

In the 90s, millions of hobbyists discovered computers and were amazed by the many demos and cracktros on computers such as the C64 and Amiga. In memory of those glorious times, I wanted to create a business card that would serve as a "Madeleine de Proust" (https://www.quora.com/What-does-the-French-phrase-Madeleine-de-Proust-refer-to) for any engineer over 40 and reminding him tunes he never heard since then. 

I also wanted not just "a concept" but a business card cheap enough it could be printed in 500 units, flashed quickly, given away and used by anybody - the way you do it with a real business card.

You can see the result here: 10 minutes of 4-channel chiptune music, packed into just 16KB, evoking the great tunes of the past synchronized with a multicolor light show :https://www.youtube.com/watch?v=YamEuNNJAxE

Several problems needed to be solved to make this possible:

    - delivering a 4 channels chiptune while using a minimal hardware (16 kb ram, cheap speaker) and fitting 15 minutes of music

    - keeping cost low

    - flashing the card very quickly, using a dedicated script

A website his dedicated to the different technology used (hardware, software, flashing script...) : www.bizcardtro.online  It is based on the v1 of the card (which was using a USB PCB, which I removed in the final version proposed here because many people will not dare putting a USB-A in their computer because or cybersecurity risk - the final version is powered from a simple USB-C cable).