Tony de Marco was my co-pilot in that workshop. Tony is an award-winning font designer, and the founder of Macmania and Magnet, two computer magazines to which I contributed many articles. He took the picture above.
Tony and I were students of Etienne Delacroix, the particle-physicist turned artist who taught PSI- 2615, Art and Programming Workshop, a full semester course at POLI/USP, a famous engineering school in Brazil. In the class each student had to build his own computer from discarded computer parts, and make it run some software with expressive intent. I wrote a sequencer in Tcl/Tk, originally intended to program a row of LEDs for a POV display, but it ended up being adapted to drive a little drum section made of cans and bottles.