Some very clever guys have figured out to make the Arduino output to analog television with very little work. Impressive stuff. Source code here.
Add a cheap shifter and you could output simple terminal graphics to a display over a serial port that would last a long time and be replaced easily over many years.
Whenever I think of buying tons of mini VGA displays as backup parts you have to consider the expense. I already have at least 4 B&W portable televisions and a green mono 12 volt display. They are much cheaper, sometimes free. Unfortunately it takes a $40 dollar bridge unit to go from the VGA to television. I was hoping for a better way.
This is actually so cool it warrants a unique VOS demon written explicitly for it to drive a display monitor. Trying now whenever time permits to consolidate a display language as a simple set of text instructions. It is hard to improve on GTK syntax for driving a display from anything.
I don't know if you are interested in this direction but I have often dreamed of some simple output format for something roughly approximating ATARI 2600 level resolution for Vault-OS that would last for years and years. This solution seems to be it.
One thing taking shape in my mind is as soon as Vault-OS is up in open source, there needs to be a port of the ANSI C source to Arduino. It is the number one target outside of X86 architectures. I was hoping somebody else could do it who knows more about the Arduino once I release the source.
What about an Arduino box glued to the back of one of these televisions as a standalone VOS server with an ethernet jack for connecting it to any number of remote terminals? That would be pretty cool. It would be pretty cheap, too, even compared to boards like the Raspberry PI.