Atari 8-bit computer peripherals include floppy drives, printers, modems, and video game controllers for Atari 8-bit computers, which includes the 400/800, XL, XE, and XEGS.[1][2][3]
Because the Atari 400/800 8-bit computers were bundled with an RF modulator, stringent FCC regulations limiting radio emissions applied. Consequently, the Atari 400/800 systems internal construction use large metal frames as Faraday cages to prevent emissions. This prevents the use of internal cards to add connections for peripherals.
To permit easy expansion, Atari developed the SIO (Serial Input/Output) bus. This bus daisy chains together all Atari peripherals into a single string. The Atari computer family was designed to be easy for novice users to expand, with one universal connector plug. Peripherals have their own IDs and can deliver downloadable drivers to the computer during the boot process. However, the additional electronics in these "intelligent" peripherals made them cost more than the "dumb" devices for other systems.