My current live performance rig is seen below. It is based on two Parallax P8X32A microcontrollers on an electronic breadboard outputting raw NTSC. All programming is custom written and stored on one of eight bank-switched memory chips, with most live visual control performed via a re-purposed Nintendo N64 controller.
The complete system includes a tiny video monitor and a small video mixer connected directly to a projector. The mixer I’m currently using is a soon-to-be-replaced SIMA SFX-M. The whole setup fits into a small backpack and is self-lit by one LED.
No computer is used during performance, though all code for the visuals is currently written on a sluggy PC laptop, and transfered to the breadboard circuit for each show.