I picked this up recently. For anyone with a Raspberry Pi who is looking to revisit some Atari games or even play them for the first time, there is a perfect emulator available for the Atari 2600 console. With a little motivation, a Raspberry Pi B board with the latest Raspian image, and a USB gamepad or keyboard you can get right to hooking a system up for some old fashion gaming. Through the emulator "Stella" and some down-loadable video game ROMs all this is achievable.
The initial set-up for the system is pretty straightforward. Assuming Your Pi is running the LXDE environment, all that is necessary to install Stella is to open the LXTerminal and enter: sudo apt-get install stella. Enter Yes when prompted and Stella will be installed. Next, you will need to tell Stella where your ROMs are located, which you will be prompted to do when opening the program for the first time.
Make sure the sound drivers are installed. (ALSA drivers are not installed by default) Enter in: sudo apt-get install alsa-utils and sudo modprobe snd_bcm2835. Permissions may be an issue. So, run Stella using "sudo stella" or add the user to the video group, which gives access to the framebuffer. This is done through: sudo usermod -a -G video pi
Once completed it will probably be a good idea to set up your controls. By clicking on options at the bottom of the screen you will be prompted with a selection of configurations. The devices and Ports tab will allow you to choose whether or not you would like to use your mouse as a controller. In addition, the Emul. Events tab will allow you to map the joystick controls to your own gamepad. Once your controls are all setup you will be ready to launch into any of the games you have available in your ROMs collection. (ROMs can be found via torrents, if you dare.)
Atari games are nice to see and remind everyone of the origins of gaming and how far we have come. However, a Gameboy, Playstation, or NES emulator that runs smoothly in the stock environment would be an awesome feature. I believe that we will be seeing these soon from some motivated hacker. (Alternatively, installing Android on the RPi will give access to emulators, no issue. Though speed is an issue.) At the moment though, a trip down memory lane to blast some asteroids sounds like a good time.