Space Invaders/Arcade

One key feature of Space Invaders was the fact that as more and more of the aliens were shot, the remaining aliens would move faster and faster. The change in speed was minor at the beginning of a wave, but dramatic near the end. This action was originally an unintentional result of the way the game was written - as the program had to move fewer and fewer aliens it ran faster and faster, but was kept after finding favour with the development team.

Space Invaders used an Intel 8080 as its processor, running below 1Mhz and a 1 bit per pixel framebuffer mapped from the main CPU address space. All sound effects were implemented individually with discrete electronics.

The actual output of the game was displayed mirror-image on a black and white monitor which sat recessed in the game's cabinet. The image was projected (automatically) to a plastic panel which the player saw. Behind the reflective panel was a lunar landscape which gave the game an impressive background setting. Since the actual video game console itself had a monochrome video image, Taito added color by coating the reflective screen with colored bands.