Atari XL Series Computers - 1090XL  


  1066 RAM Card Schematic

  Z80 CP/M Card Schematic

  Z80 CP/M Card Mechanicals

  80 Column Card Mechanicals

  Parallel/Serial Card - ROM








Atari 1090 XL Expansion Cards


Atari 1090 CP/M Module.   (This was to be the 1090 version of the "Sweet-Pea" which was an external box called the Atari 1060 CP/M Add-on.   The 1090 CP/M card is the Atari 1066.)   This expansion card would have allowed an Atari computer to run software written for Zilog Z-80 processor CP/M (Control Program for Microcomputers) computers.   The card contains a Zilog Z-80 processor and support circuitry.   However this board has not been able to be tested since no software drivers have yet been found.   The card does contain an expansion header, it is unknown whether or not this header may have been used for a daughter card with RAM or perhaps a floppy disk controller board or some other feature.



Atari 80 Column Video Module.   This is a bare unfinished board.   It capabilities are unknown.  Whether or not it had character attributes and multiple split screens similar to the Atari Corp XEP80 80 column/parallel port module is unknown.   However it is most likely a necessary board in conjunction with the CP/M module since most CP/M software would have functioned more properly in an 80 column mode.



Atari 64K Memory Module.  Up to 3 of these modules could have resided within the 1090XL expansion chassis.  They would be daisy chained together via the expansion header located in the top center of the card.  The card had 2 "Personality" modes.  One mode was the "Bank Switching" mode for use with the 800XL, 1400XL and 1450XLD.  The second mode was the "1064" mode which would have allowed a single memory card to act as a 1064 expansion module.  (The 1064 Expansion module was a 64K box which could only plug into an Atari 600XL giving it 80K of total memory).


Atari Parallel/Serial Card.  One of the very first boards to be released for the Atari 1090 XL Expansion System.  This was a "device card" which meant it had to have a Device ID setup on it. There is a Device ID dial on the board and it would be set from 1 to 8.  Interesting backstory of the Parellel/Serial card: it was not developed in-house by Atari. Rather it was contracted to an outside developer - his name is Joe Decuir. Does the name sound familar? Well it should, Joe helped develop the TIA chip in the Atari 2600 and helped develop the ANTIC chip in the Atari 400/800 and was part of the 400/800 design team.  He was contracted to develop this Parallel/Serial card for the 1090. The Atari Musuem would also like to thank Joe for the loan of the card so it could be photographed and its ROM and PAL chips dumped for posting up.


Are you a former Atari engineer?  Did you work on the 1090 or have direct knowledge of this project? 

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