Greetings-
I am trying to replace a broken Ceronix 1492 13" monitor with a VGA LCD monitor.
I have purchased one of the CGA/EGA/YUV to VGA HD-Converter PCB (model GBS-8220) cards from Jammaboards.com - pictured here:
The documentation that comes with it is poor, to say the least. It is, however, supposed to be able to convert CGA to VGA.
As a simple test to make sure my board was working, I used the Y Pb Pr inputs on the card with video from my DVD player, and it did convert it nicely to my VGA monitor, so I know the thing is somewhat functional and I know that it's compatible with the VGA monitor I'm using.
I think I'm bumping into a sync issue. The game I'm working on outputs R, G, B, Ground, Horizontal Sync, Vertical Sync. The GBS-8220 does have an input section that, according to the printing on the board is: Ground, Ground, VS, HS, S, B, G, R. I have reason to suspect that the "S" here for this input is actually "shield" and not composite sync, and I'm not 100% sure what that means. Regardless...
I tried hooking up my RGB, Ground, and VS and HS and would only occasionally get a flickering of something on the monitor, usually in a single color (green, blue, or red mostly) for just a second or two here and there. The rest of the time I'd get a "No Signal" message generated from the GBS-8220 card. From the tiny bit I could see, however, it did in fact appear that it was trying to display the signal the game was sending out.
The documentation (again, limited) implies that for RGBHV input, it only accepts in the 31k range, which CGA is not. It does say that it accepts CGA at its 15k, but it seems to imply that for CGA it requires RGBS (Red, Green, Blue, Composite Sync) which one of the other inputs on the board ("P3" for those of you playing at home) is (which also has a ground pin, in addition to RGBS). As such, I'm guessing that I can't hook up my CGA output to the card as RGB H V.
So... my question is, has anyone used one of these boards to convert a CGA signal that used RGB H V into a VGA monitor, and if so, how do you have it connected? Do I need to somehow combine the sync signals and then try it on the P3 connector as composite sync?
Thanks in advance for any assistance you folks can provide.