I have an NEC MultiSync II that works with VGA/EGA/CGA/TTL and apparently had converters that allowed it to work with the Amiga, Commodore 64, and Atari ST as well. To use it with a 15 pin VGA monitor you have a special 9-pin to 15-pin converter, I've always wondered if I should open that up and do pinout/schematic of it since it's a cool thing to have. Might also be asomething standard to use since it seems Mistubishi and Panasonic made similar monitors.
A funny side note, the NEC MultiSync II I have says 800x600 is the top resolution but somehow Seagate Disc Wizard got it up to 1024x768 or so it seems.....fuzzy as heck, but no whine and was still usable like that....kind of shocking in a good way for a CRT from 1988. Had the Horizontal and Vertical position dimed to lower right almost.