I found a CRT monitor (around 15.5") on the side of the road, it was sitting there with a printer, a photocopier, a washing machine and a PS/2 keyboard (but no computer).
I brought it home and wiped it down, and connected it to power and my BeOS laptop.
I powered on the computer, and then I see the BIOS POST screen from the laptop, on the CRT.
I didn't use it much with my BeOS machine, as I didn't really have enough space in my room to have both out at once.
At the moment, I have it plugged in to my 32-bit desktop, running FreeDOS off a USB, although naturally, I tried out Haiku on it as well.
Now for some pictures:
DOS, with my custom menu system

Haiku, with an IRC client

This thing is pretty deep!
