Adaptive tile refresh is a computer graphics technique developed by id Software's John Carmack wherein only the graphical elements that have moved are rendered anew, thereby saving the computing power required to redraw the entire screen.[1] He invented it to compensate for poor graphical capabilities of PCs in the early 1990s. To make sidescrolling games possible, adaptive tile refresh was the only technique available. This technique was eventually used to create the PC's first sidescroller, Commander Keen.
Adaptive tile refresh made its first appearance in an unreleased test-version of "Dangerous Dave in Copyright Infringement". Dangerous Dave was a title previously used by John Carmack while programming games for Softdisk. The sole purpose of this game was to test adaptive tile refresh in a realistic environment, and the game was created within a very short time frame. Adaptive tile refresh had never before been used in a game, and when Dangerous Dave in Copyright Infringement was complete, it stretched the boundaries of what was thought possible on a PC at the time. The game was a port of Nintendo's Super Mario Bros. 3, but Nintendo declined the offer to release the game after id Software finished it. It was kept mostly secret, and it was never released to anyone other than the pre-founders of id Software.
Adaptive tile refresh made its first market appearance in id Software's first installment of the Commander Keen game series, Marooned on Mars. Commander Keen was an immediate shareware success, due to its groundbreaking features and gameplay. Never before had a sidescrolling PC game been able to even run, let alone render as smoothly as Commander Keen.