This was my second attempt at a party light show thing. It was roughly based on an IntelliBeam club light.
It consisted of a spotlight pointing at a mirror that could rotate left and right, as well as pivot up and down. The construction was a PVC-based structure that could be disassembled for ease of travel. It was all controlled via a ITC-232 serial interface board connected up to my Amiga, where I was going to write the controlling software.
The electronics consisted of the serial interface board, and a mess of wires and stepper motor driver chips. I got it basically working, but I never found a good light source, nor did I ever write the GUI software to control it.