The Atari 800XL was the third version of the Atari XL 8-bit line of computers introduced in 1983. It specifications were completed in late March 1983. The system contained a full 64K of memory, had all the standard Atari chips (Antic, GTIA, Pokey, PIA) and was in a smaller and more compact design than the 1200XL which it was designed to replace. The keyboard was good, but not nearly as good as the 1200XL keyboard, but it had a solid feel to it.

The cartridge port had been move to the top center of the system in the same fashion as the 600XL and used special metal spring loaded doors to allow the insertion and removal of ROM cartridges. This system of spring loaded doors also kept dirt and objects from falling into the cartridge slot when it was not occupied. Overall the system is basically a cost reduced Atari 1200XL, but with a better video display, expansion bus and a much lower retail price.

The system, just like the 1200XL also came with built-in diagnostics and a HELP key, however it provided one important improvement: Built in BASIC. The OS was still slightly incompatible with many original Atari 400/800 software titles, but Atari began to distribute a "Translator" disk which would load up a 400/800 compatible OS into memory so that the 800XL could support those programs.