What saved the [Atari] VCS, ironically, was the lack of a frame buffer. Yes, the system could only display two sprites at any given moment. But once the electron beam had drawn a sprite, the program could shift the position of said sprite horizontally and redraw it. But because the sprite had already been drawn on the screen, the original one would not disappear until the electron gun came back around to redraw the screen. By doing this, programmers could create rows and rows of sprites — perfect for Space Invaders‘ rows of aliens. Eventually, use of these techniques allowed designers to create scenes on the VCS that were significantly more detailed than the hardware maker had ever imagined.
Racing the Beam: How Atari 2600’s Crazy Hardware Changed Game Design
