This is the final version in NTSC format (which was not
released).
These EPROMs were found accidentally by an Atari collector
ordering used EPROMs from Jameco (a major electronics parts
retailer). How Jameco ended up with Atari 2600 prototype
EPROMs is unknown, but these may have been part of Atari's own
internal archives due to the large number of duplicates.
These EPROMs may have then been sold as scrap when Atari Corp.
merged with JTS Inc. in 1996.
Where's my Fuji???
I'm amazed they could do the "Klax
Hand" on the 2600