Atari 1090 XL
EXPANSION CARD #1:
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
EXPANSION CARD #2:
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.
EXPANSION CARD #3:
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).
EXPANSION CARD #4:
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.