The Atari 6402A motherboard is a mystery in itself.    Basically the system board is slightly wider then the 1200/1400XL computers and almost also deep as the footprint of the 1200/1400XL.    The system board has all the features of the 1450XLD including the on-board disk drive controller, and modem.     However the interesting part about this motherboard are the ports and their placement around the system board.   All the connectors are set back into the motherboard away from the edges.  

This would mean that they would not have been able to sit into a case so that the ports would be flush and accessible.   Also notice how all the ports are on all 4 sides and the keyboard and PBI connectors are located on what is believed to be the front of the system board.    It seems that this motherboard was meant to be more of an in-house lab test than something that was being slated for production.    

 

Atari was having many problems with the 1450XL daughter cards which contained the disk drive controller for the system, its possible that this motherboard may have been a platform for testing of the disk drive controller.     At this point in Atari, Inc's agenda, Atari was focusing on the completion of the 1450XLD system and was concentrating on its new Next Generation computer system code named "MICKEY".   Mickey was to be the Atari version of the Amiga computer system prior to Atari's sale to the Tramiels and Commodore stepping in and buying Amiga Corp.
 

Next comes the name of the motherboard.   Why the designation 6402A?    The CPU is a 6502, so why 6402?   Its rather strange and puzzling.     The staff of The Atari Historical Society would be grateful if any ex-Atari engineers out their who may know something or anything in regards to what was going on as far as development work on the 1450XLD and this rather odd 6402A  motherboard would please contact us and help fill in the missing pieces on yet another Atari mystery.
 

 

 

Are you a former Atari engineer?  Did you work on the 1450XLD or have direct knowledge of this project? 

Please contact the Atari Museum:  CLICK HERE