Well,
Its says CGA/EGA/VGA right on the retail box of the monitor as I had 3 of these.
I have one of these monitors in a retail box sitting on the floor right next to me as I type this reply an no where on it does it say CGA/EGA/VGA ,it has a box on it that says vga/std or dx and cga/std or slt that the manufacture checks depending on what type of monitor gets puts in the box before it goes to the distributor. These monitors are nothing but regular open frame VGA computer monitors with a max resolution of 640 x 480 so I don't think he can do this it without ruinning the monitor or the board or maybe both.
NOW,you can either cut the vga cable then look for the red,green,blue,ground,sync wires then hook it up directly.It wont hurt the monitor as you are goin down with the scan rate here.Then use a swith box to swith between your jamma boards and PC.
If this were true in theory you could do this with all monitors that support higher resolution an scan rate with out special software or hardware but thats just not the case.
horizontal scan frequency range
Wells gardner d9200 series monitors
15.75 to 31.5 KHz
Should work but I would call WellGardner to make sure
Eygo 19" vga model # amn19v-rb
30.5 to 32.5KHz
Will not work
IMHO
Rodney