In the test of the /dev/link device, I used another instance of TiEmu running PedroM to send a variable to this calculator. This could also be done with the "Send file to TiEmu..." menu option in TiEmu itself, but that blocks the use of the calculator while the variable is transferring (remember that Punix is a multi-tasking operating system, so that is kind of annoying).
For the test of /dev/audio, headphones or speakers are required, but only if you want to hear the stereo test tones. :)
I still just need to work on getting the filesystem and binary execution working, and then we'll be very close to a working system!