Hello,
I have designed and built the ParanoiaBox, a device for embedded encryption. You connect a keyboard, TV screen, and then you can compose and encrypt messages that are transferred using SD cards. You can find the software and hardware at
https://github.com/profdc9/ParanoiaBox/
There are also NTSC video character generation libraries and PS/2 keyboard libraries I made for it. You can find those at
https://github.com/profdc9/ParanoiaBox/ ... /libraries
Anyways take a look at it!
Thanks,
Dan