Features:

• High speed emulation using optimized C++ code
• Supports high quality sound emulation using code derived from Ron Fries' TIA Sound Emulation library, including stereo sound support
• Emulates the Atari 2600 Joystick Controllers using your computer's keyboard, joysticks or mouse
• Emulates the Atari 2600 Keyboard Controllers using your computer's keyboard
• Emulates the Atari 2600 Paddle Controllers using your computer's mouse, keyboard or joysticks
• Emulates the Atari 2600 Driving Controllers using your computer's keyboard, joysticks or mouse
• Emulates the CBS BoosterGrip Controller using your computer's keyboard, joysticks or mouse
• Emulates the Sega Genesis Controller using your computer's keyboard, joysticks or mouse
• Emulates CX-22 / CX-80 style trackballs and Amiga Mouse using your computer's mouse
• Emulates Spectravideo CompuMate system using your computer's keyboard, including mapping of CompuMate 'Backspace', 'Space' and 'Enter' functionality to to the actual keys on your keyboard
• Emulates the Mindlink Controller using your computer's mouse
• Support for real Atari 2600 controllers using the Stelladaptor and 2600-adaptor/2600-daptor II
• Support for the speech portion of a real AtariVox device connected to your PC using a USB adaptor
• Supports all known bankswitching schemes (let us know if there's one we missed)
• Supports ROMs stored in ZIP and GZIP format, as well as the usual A26/BIN/ROM formats
• Full system state save/load functionality
• Built-in extensive debugger, including static analysis with the Distella disassembler and dynamic analysis at runtime by tracking code/graphics/data sections, and generation of DASM-compatible disassembly files
• Emulation of CRT TV systems using Blargg filtering, including presets for several common TV outputs (composite, S-video, RGB, etc), and ability to fully customize many attributes (contrast, brightness, saturation, gamma, etc).
• Built-in ROM database with information compiled by RomHunter

Locating Game Images (ROMs)

• Search around the internet and find ROM images to download (websites such as AtariAge and AtariMania/RomHunter may be useful)
• You can purchase the Atari 2600 Action Packs by Activision and use their ROM images

WARNING: It is illegal to use ROM images of games that you do not actually own since these games are still copyrighted.