The Atari 400



    Technical Data & Tear Down

    Atari BASIC

    Atari 400/800 Hardware Manual






The Atari 400, also known as "Candy" was Atari's second computer released in 1979 along with her big sister, the Atari 800 which was known as "Colleen".


The Atari 400 was also referred to as "The Basic Computer." It was meant to be an entry level computer but it was a computer in search of its real purpose.   Candy was meant to be a video game system with a computer keyboard, but last minute decisions changed its design to be a low end computer and less of a video game system.

Candy, just like Colleen would have a rather unique case design.  Douglas Hardy who was the co-designer of the original Atari 2600 VCS console designed the very unique and elegantly high tech looking case for the Atari 400.  It too had a 2mm thick aluminum RF shield over its internal electronic components and this also compromised part of the Atari 400 case.  When opening the cartridge door, the user could see the aluminum chassis within.   The cartridge door on the Atari 400, just as on the Atari 800, had a safety switch that turned off the computer when the door was opened to protect it from accidentally inserting or removing the ROM cartridges from the cartridge bay within.


The Atari 400's originally shipped with 8k but that was changed very quickly to 16k.   The unit has an SIO (Serial I/O connection port on the side) for connecting Tape drives, modems and printers.  To use more advanced programs and disk drives the Atari 400 would need to have more RAM memory added.  Unlike the Atari 800 which had an easily accessible expansion bay to instead memory modules into, the Atari 400 would have to be physically opening to have larger memory installed

The Atari 400's lack a composite video monitor port on them and can only be connected to a TV through an RF connector.  Since the system was meant to really be more video game console than computer, the keyboard is a kid friendly membrane keyboard which is meant for just casual key presses, not for touch typing.  Using it for Word Processing, On-line communications usage or Programming becomes cumbersome, tiring and frustrating.   Several companies did release keyboard upgrades for the Atari 400 though.


(Work in progress, more content to be added, updated 3/18/2019)