I proposed and helped fund an open-source Nintendo 64 crypto app. There's also a Linux version. It has features like converting dice rolls to Bitcoin wallet addresses, and encrypting/decrypting data. The only input is the N64 controller, the only output is the N64 video output.
This is designed to become arguably the most secure option for securing your stack, but it can't be recommended for more than testing until it gets at least some thorough third-party code review.
Git
https://github.com/bowler-bear/retro-crypto
Original proposal / dev discussion thread
https://bounties.monero.social/posts/168/
I also made a small showcase video about the project:
YouTube (watch only)
https://youtube.com/watch?v=jYAqatkyquU
Nostr (watch or download)
https://jumble.social/notes/nevent1qvzqqqqqqypzqamkcvk5k8g730e2j6atadp6mxk7z4aaxc7cnwrlkclx79z4tzygqyvhwumn8ghj7urjv4kkjatd9ec8y6tdv9kzumn9wshszrnhwden5te0dehhxtnvdakz7qpqsegyykcmq70qdm5u58x8uetucd4pujp27ta66hp7fc8asmlfwrlqyun6n8