Atari CX-55
2600 Cartridge Adapter
for the Atari 5200 Supersystem


        Originally the design of the Atari "PAM" (also known as Super-Stella and Sylvia) was to have built in Atari 2600 compatibility.   However, during the development the architecture of that version of the new Atari "SuperSystem" was dropped in favor of a new Atari "PAM" which became the Atari 5200: SuperSystem.    This system was based on the Atari 400/800 computer system chipset and would not be compatible with the Atari 2600 game console.    With enormous pressure coming from all sides with Coleco and its Colecovision 2600 adapter and Intellivision with its "System Changer" which gave it 2600 compatibility Atari designed and released an adapter of its own for the Atari 5200 Supersystem.     The Atari CX-55 2600 cartridge adapter was the result.    Many consumers complained about the odd way the adapter stuck out of the top of the Atari 5200, then a cartridge had to be plugged ontop of the CX-55 making for a clumsy looking arrangement.   The reason for this was the Atari 5200's top cartridge port was never intended to accept any kind of expansion modules.    All expansion was to be done from the rear expansion port on the console.    Due to the 5200's sleek angled design the CX-55 module was made to sit straight up.    If the design had been made for the module to sit flush ontop of the Atari 5200, this would have involved the need to design specially angled electrical connectors which would have added to the price and may have lowered reliability.    Time was precious and the design was kept simple.

        While the Atari CX-55 adapter brought a whole world of existing games to 5200 owners, it came with a few requirements.    In order for the module to work, the Atari 5200 owner had to own either a 2 port Atari 5200 (having only 2 front joystick ports) or a factory modified Atari 4 port 5200.   Otherwise they would have to take their Atari 5200 to an authorized Atari Service Center who would perform, free of charge, an upgrade to the owners 4 port model to make it compatible with the Atari CX-55 module.

        Originally when this incompatibility issue arose at Atari, the solution was to scrap over $1 million dollars in existing Atari 5200 4-port system boards.   However one of Atari's Consumer Electronics Division engineers named Gary Rubio came up with a quick and easy modification for the existing stockpile of 4 port 5200 SuperSystems.     Below are the 3 pages from an Atari Internal Memo detailing the modification.


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