The Vectrex was a unique home video game console that was originally released in 1982. Unlike most consoles of the era — and today — that output the graphics to your television, the Vectrex had its own built-in vector display. Instead of scanning horizontal line by horizontal line, the vector display drew graphics from point-to-point like a plotter. The result was an interesting aesthetic, but the screen was small. Over on his YouTube channel, Arcade Jason has expanded that with a DIY projector system.
A normal CRT (cathode-ray tube) tube, like you’d find in an old monitor or TV, usually works by displaying raster graphics line-by-line. An electron beam is swept back and forth rapidly across the screen, moving down a line after each pass and pulsed to show either a light or dark spot. But, the electron beam doesn’t have to be controlled in the manner. It can be aimed however the controller tells it to by precisely adjusting the yoke voltages that move the beam in the X and Y axes.
Arcade Jason’s build takes advantage of that fact to turn a regular old monochrome CRT into a vector display like the Vectrex used. The display board from the Vectrex is simply connected to the yoke of the CRT that aims the electron beam. To enlarge and project the image on the CRT, Arcade Jason used a lens that was salvaged from an old rear-projection big screen TV that was found on a curbside. In a dark room, it works surprisingly well, and now Arcade Jason can play the Vectrex with nice, big graphics.