Altirra

Altirra is an open source, cycle-accurate emulator for the Atari 5200 and Atari’s 8-bit home computers, for Windows. It was written by Avery Lee, the creator of VirtualDub.

First released in 2009, Altirra is one of the newer Atari 5200 emulators, and it quickly became regarded as one of the best thanks to its cycle-accurate emulation.

It is widely considered to have the most accurate emulation of the Atari 400/800, 1200XL, 600XL/800XL, 130XE, XEGS and 5200 systems, and it even reproduces undocumented behaviour of the hardware.

If you want a fast and very accurate emulator for the Atari 5200 or Atari’s 8-bit computers, Altirra is the one to try first.