Part 3: The Hidden Future.

The Atari 800 expansion bays, the SIO Bus and the front controller ports all gave the Atari 400 and Atari 800 computers a lot of possibilities to expand.   However something was lurking deep with the Atari 400 and Atari 800 PCS computers.  A Parallel Bus Interface...

On the back of each of the Atari 400 and Atari 800 computer systems main boards (Motherboards) were a large Test header.  This header access into all of the chips and logic with the computers.  Atari had created an expansion bus.   Sadly the lack of foresight prevented someone at Atari from saying: "Lets put a removable plastic panel behind the Atari 800 case and have an aluminum cap over the test point headers so it could be removed and an external expansion card cage could plug into the back of the Atari 800 to give it several fully capable and externally accessible expansion slots.    Had Atari engineers done this and Atari released something like an Atari 900 Expansion bay, the Atari 800's could've saw a much broader array of expansion capabilities, perhaps things like Modem cards, floppy drive controllers, RGB video cards and even network cards.

However, all was not lost, someone did eventually realize this and in the coming years a new line of computers called the Atari XL series would have PBI (Parallel Bus Interface) ports on the back of them and had the potential of opening the door to more expansion capabilities from the Atari computer systems.   See the Atari XL series computer section for more information on those computers.

The Atari 400 and Atari 800 computers continued to be sold through part of 1983 despite the fact that in January 1983 they would be replaced by a new computer system called the Atari 1200XL.

2019 marks the 40th anniversary of these amazing computers.