Here is a weird/dumb idea: using an ancient serial text terminal as an additional monitor. Doing this with the terminal's keyboard is easy – just run a getty on your serial port and you're done. I want to do something a bit weirder – I want to use my PC's usual keyboard, having the text terminal be nothing but a passive display. It's a bit tricky, since this is totally contrary to what text terminals are actually for.
Here's my work so far.
The idea is to use screen to set up the session in a terminal emulator window. For now, I'll resize this window as small as possible, and just use it as a thing to click when I want to start using the dumb terminal. Eventually, the idea would be to have a little tray app that hooks the keyboard when you do a key combination.
To have the dumb terminal be the display for this screen session, I'll tie screen it to my serial port via getty, e.g.:
$ getty -nl /usr/bin/screen 115200 ttyS1
Then I set up my listener window with:
$ screen -rx
Some quirks – I want to actually have two screen sessions: one to bind the window and dumb terminal to one session, and one nested inside which will have multiple tabs. These sessions need different configs – I don't want ANY shortcuts for the outer session, and I want fancy shortcuts & UI for the screen interface I actually use. This will mean multiple screen configs (-c option), and the inner session will have to be started with the -m option (to allow for nesting).
Of course, step 0 is to get a physical dumb terminal…right now I just validated this with two VMs serial-ported together.