PSone VGA mod

If you're making a portable you probably need something to watch it on. (Unless you want to guess what's happening in the game, but I wouldn't advise that) Anyway, this forum is your "Hacking a pocket TV/screen" one-stop solution. Share your experiences and knowledge here.

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superdeformed
Portablizer Extraordinaire
Posts: 298
Joined: Thu Mar 03, 2005 4:45 pm

PSone VGA mod

Post by superdeformed »

I've been trying for a couple days now to get this to work properly. I have everything wired up right, an H/V-sync to C-sync converter as my graphics card (geforce fx5200) doesnt support c-sync, and all of the correct timings. In fact, it displays just fine...except my graphics card won't recognize it as a monitor at all.

I managed to get it working by plugging in an old monitor then swapping it out, but as soon as I touch anything in the nvidia control panel it disconnects. I found one other post regarding this (Foxx373 was having the exact same problem), but the issue was never really resolved. I had previously tried forcing a 75ohm load across each color line to ground, but the colors are way too washed out. So, has anyone else had this problem and been able to find a good solution to it (other than a switch on the resistors)?
olderthanyouthink
Posts: 13
Joined: Thu Feb 02, 2006 2:25 pm

Post by olderthanyouthink »

I had this problem on an ArcadeVGA card once. It has to do with the way modern video cards detect the presence of a monitor. When I asked the maker of the card he suggested exactly what you have already tried, putting a resistor inline with each of the RGB lines (3 total). I don't recall the values he gave me to use, however, but I do remember him suggesting that it might make the screen washout.

Fortunately for me, the monitor I was trying to drive was a pretty crusty arcade monitor that didn't care too much about voltage levels on its inputs. In the case of your failry modern LCD, though, it's probaly a different story.

You might try lower value resistors.

Also I peeked at google quickly and found this, might shed some light on what's going on:

http://www.mp3car.com/vbulletin/archive ... 45720.html

Basically you may be able to force the driver to do what you want.
superdeformed
Portablizer Extraordinaire
Posts: 298
Joined: Thu Mar 03, 2005 4:45 pm

Post by superdeformed »

I think I've got everything working now, but thanks for the link :D. I found a chart for monitor ID hookup positions, and also discovered that DVI doesn't support it (I had it hooked up through a VGA-DVI adapter, my normal monitor is on that now). It seems to me that there really isn't any noticeable difference between RGB and composite (aside from brightness and more color control), oh well. Now to solder on a new VGA connector...I've mangled the pins of my current one playing with resistors and ID pins :).

Edit: Scratch that...I updated the display drivers and it won't recognize it again :(. I think I'm about ready to throw in the towel on this one.
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