Retro builds for unreleased Atari 8-Bit ports of Defender/Stargate developed by the late Archer Maclean have been dumped and posted online

[Krvavi Abadas]

for those unaware, he sadly passed away back in December of last year. at the time, it was unknown what would happen to the many development materials he created over the years, but it seems like they've ended up in good hands.
the builds run the full gamut of development. from early experiments in BASIC to the nearly finished project he pitched to Atari.
in both cases, he was rejected due to another Atari developer already working on porting the game. (though the "official" Stargate port would never see release regardless thanks to the North American video game crash.) rather than giving up entirely, he heavily retooled the work to create his own original arcade game called "Dropzone". which would go on to become of his most popular titles.

 

[Krvavi Abadas]

It’s various tests for recreating arcade games on Atari 8-bit hardware, it’s unlikely any of these were pitched to a publisher like Defender though.
there’s also disks containing various artwork and sketches.

and prototypes of his other classic title International Karate. (including the + re-release)