Editing Jumpman (video game) (section)

===Technical details===
Movement was controlled through the [[collision detection]] system of the Atari's [[Sprite (computer graphics)|player/missile graphics]] hardware. This system looks for overlap between the sprites and the background, setting [[Processor register|registers]] that indicate which sprite had touched which color.<ref>{{cite book |first= Chris |last=Crawford |title= De Re Atari | publisher =Atari Program Exchange |date= 1982 |chapter= Hardware Collision Detection |url= http://www.atariarchives.org/dere |chapter-url=http://www.atariarchives.org/dere/chapt04.php#H4_8}}</ref>

Glover separated the Jumpman [[sprite (computer graphics)|sprite]] into two parts, the body and the feet. By examining which of these collided, the engine could determine which direction to move. For instance, if both the body and feet collided with the same color, it must be a wall, and the Jumpman should stop moving. If there was no collision with either his feet or body, Jumpman is unsupported and should fall down the screen. Variations on these allowed support for ramps, ropes, and other features.{{sfn|Glover|loc=20:00}}

This not only saved processing time comparing the player location to an in-memory description of the map, but also meant that maps could be created simply by drawing with them and experimenting with the results in the game.{{sfn|Glover|loc=22:00}}