Editing Atari 800 (section)

== Input/Output and Expansion ==
The Atari 800 was designed for expandability and robust I/O:
* '''Two cartridge slots''' (one primary, one auxiliary) for software and hardware expansion.
* '''Four joystick ports''' – compatible with Atari-style controllers.
* '''Peripheral Interface Bus (SIO)''' – daisy-chain connection for disk drives, printers, modems, and cassette recorders.
* '''Composite and RF video outputs''' – for connection to TVs and monitors.
* '''Parallel bus expansion slot''' (underneath) for memory and future upgrades.
* '''Full-travel keyboard''' – 57 keys, including function keys and a HELP key.

The system's modular design and shielded, rugged case made it suitable for both home and educational use.