NOTE: I'm basically dropping links related to the DEF CON 26 badge. Once I get the time to work on the badge, my findings will follow.
Hackaday
https://hackaday.com/2018/08/09/first-look-at-def-con-26-official-badge/
Arstechnica
https://arstechnica.com/information-technology/2018/08/honoring-the-80s-defcons-badge-is-also-a-text-adventure/
Badge Emulator
https://github.com/m0n73/dc26_BadgeEmulator
Flash the firmware?
https://www.reddit.com/r/Defcon/comments/96t4w9/we_got_a_green_badge/
Mega-Info Link
http://www.deaddialect.com/articles/2018/8/17/badge-story
Reddit: Terminal Recordings
https://www.reddit.com/r/Defcon/comments/986m1c/def_con_26_badges_terminal_recordings/
The green "E" hack.
https://www.reddit.com/r/Defcon/comments/99lfny/fixed_one_of_the_dc26_badge_bugs_to_get_a_green_e/