I believe very early I, Robot boards(Ice World?) used a ttl circuit in place of the ICY.
You may be able to get some info from the pics of these two sold lots.
www.rrauction.com
www.rrauction.com
You may be able to get some info from the pics of these two sold lots.
Atari 'I, Robot' Project Document Archive from the collection
Sold for $27,188 | Substantial archive of development material for the innovative Atari, Inc. arcade shooter game I, Robot, deriving from the personal
Atari 'Mondo Bondo / Boffo' 3-D and Video Processor Archive
Sold for $4,441 | Extensive archive of development material related to the Atari, Inc. video processor project ‘Mondo Boffo’ and the 3-D processor
