I once worked on a project that ran 4 monitors off one Amiga. Using a graphics card to do a byte per pixel main display (polygon + scaled sprite 3d), and three

I once worked on a project that ran 4 monitors off one Amiga. Using a graphics card to do a byte per pixel main display (polygon + scaled sprite 3d), and three monochrome displays taken from the red green and blue output of the Amiga's standard video out. Each of the monochrome displays used a single bitplane plus shared a random static bitplane. By adjusting the palette you could individually control which monitor the image appeared on, how bright it was and how much static interference to display. Various other failure modes were also added via copper tricks (roll, glitching etc.) without modifying the base bitmap.