GeckOS is advertised as an extremely easy OS to port to alternative 6502 platforms

Only a theoretical port. 6502-based OS with a highly portable nature. Could absolutely end up here.

https://lobste.rs/s/xzfgrr/geckos_unix_like_6502_operating_system

http://www.6502.org/users/andre/osa/index.html

https://github.com/fachat/GeckOS-V2

https://en.wikipedia.org/wiki/GeckOS

For general information, see the Game Console Revisions Overview.

There are two versions of this console, arranged chronologically.

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The original run of the 7800, which had to cease production later that year due to finances. Sold only in southern California at first. Upon the 1986 relaunch, all overstock from the 1984 run was sold, but it is unknown if sales were still limited to California or not. The only noteworthy difference to the later run, is the presence of an unused expansion port on the left side.

Identical to the 1984 run 7800, except the expansion port is now gone.

There are two revisions within the 7800 (1986-1992), and no revisions within the 7800 (1984).

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Outside of a minor motherboard change, this Atari 7800 version has no expansion port anymore. However, there is an indent located where the port used to be. This version may have a minor incompatibility with “Dark Chambers”, a 2600 game.

The exact same as above, except either a small outline or nothing at all replaces the expansion port indent. Aforementioned “Dark Chambers” defect may not exist, however, games using FE-bank switching may be incompatible instead (Centipede, Kool-Aid Man, etc.)

BEST RELIABILITY couldn’t be assigned.

https://en.wikipedia.org/wiki/Atari_7800#System_revisions

http://www.ataricompendium.com/game_library/easter_eggs/7800/78prosystem.html