Altirra

Altirra is an open source cycle accurate Atari 5200 emulator for the Windows Operating System. Developed by the creator of virtualdub.org. Altirra like many Atari 5200 emulators, also emulates Atari’s long list of 8-bit computers that they released around the same time as the Atari 5200.

Originally released in 2009, Altirra is one of the newer Atari 5200 emulators, and has quickly become regarded as one of the best thanks to its cycle-accurate

Altirra is one of the best emulators for the Atari 5200, and is regarded as having the best in class emulation of the Atari 400/800, 1200XL, 600/800XL, 130XE, XEGS, and 5200 systems. Altirra even goes as far as to successfully and accurately emulate undocumented functions of the systems.

If your after an extremely accurate, fast and all round fantastic emulator for the Atari 5200 and Atari 8-bit systems you cannot go past Altirra.