Here is a demo of it working
The Software basically slows down a computer serial connection by such a large factor that we humans can comunicate to it through sound. The computer interprets sound as 1s and silences as 0s. As long as the musician is able to keep to a steady BPM (in this case 120) they should be able to transmit letters to the screen. That said, it is pretty hard, Wan Lin Qin was one of the students I produced standard musical notation to attempt it.
The gallery installation
I also produced a drawing a drawing of serial can be converted into music, it is really wide, so here is detail.