I managed to use an old amiga computer monitor for a test monitor. It's not good enough to play a game on but it does do the job.
I will need to sit a mirror in front of it so the image is not mirrored.
....or you could swap the Horizontal-Yoke wires on the monitor neck, to do the mirror-flip, or even put the wires thru a switch so you can revert to using the monitor normally for anything else ;-)
MM
