Help with PSONE LCD mod

**starfox** · 06-06-2004, 11:32 PM

Nice circuit

I should kick that kickassamd article writer, read through his article and he ripped my images without asking for permission and didn't say anything about the XOR circuit that most people will need.. grrr

Btw.. the "DCC" pin is actually just a 5V supply pin, which can be used by a monitor to sense if there's something plugged into the VGA port. I just used it to give the PSOne a 5V signal so it switches on.

Mesuge: Check that you don't have sync on green switched on, other than that all i can think of is check your cable connections are okay. Use ae multimeter with a continuity tester (with the psone display switched off of course) and check that there's a continuous connection between the VGA pins and the PSOne lcd for all of the pins required, and that there are not shorts.

**MatrixPC** · 06-07-2004, 12:21 AM

Another note is that the circuit above works for any video card. The circuit is basically used to convert HSync and VSync into CSync so that those "CSync only" monitors can works. What you looking for is a video card that support custom resolution of 640x480i @ 27~30MHz. That is the only resolution PSOne works. Matrox Mill G200 is one of few others.

**dignome** · 06-07-2004, 12:35 AM

I found a small table of cards that supposedly work...

http://www2.cs.uh.edu/~scamp/

Someone should create a new topic dealing with which cards will and won't work along with their quirks so that others may know. Then people with working cards can add to it and a list will grow from there.

**starfox** · 06-07-2004, 01:49 AM

There is a thread for a list of cards that work, i started it a while ago, and it's summarised in that table that you've posted. I actually did 4 of those tests as that was the hardware that i had at the time..

The 9200SE entry has errors in it, the 9200SE that i have (powercolor) doesn't actually have csync output, and the card doesn't display anything at all if you drop the horizontal refresh too low. I'm not sure why this is, maybe the SE in 9200SE stands for s**tty edition

**Mesuge** · 06-07-2004, 02:16 AM

Thanks! Btw. for the millenium G200 is it desirable to use your XOR circuit as well? I was under the impression from starfox's (serio) tutorial that G200 falls into the "1st" category which has no probs with csync output and doesn't need anything extra.

Also, call me a dumb head, but could you pls. clarify that vga ground pin 4, (10), 11 issue? - from the the article it seems to me you have to connect it to r,g,b grounds but I would rather connected it to psx pin #1 (ground) as shown in the M-Pro mod..? So, there will be 2 separate grounds wiring..

**Mage** · 06-07-2004, 02:31 AM

I have 3 questions still one I dont have csync (atleast not the option in powerstrip) are there is the above thing work for that? and 2 everytime I reboot and powerstrip restarts I get "powerstrip was not shutdown proporly" and 3 why do I have to keep resitting the screen vertacly? it's alway half way I have to move it down or up to get it right.

Mesuge: I had a Millenium 2 not the G200 I went and got a G5 PCI and got it to work to me sounds like you wire might be messed up.

thanks
Mage

**JoyRidun** · 06-07-2004, 02:43 AM

Originally Posted by Mage

bump

What does it meen when someone says "bump" on a forum... ?

**starfox** · 06-07-2004, 05:55 AM

Mesuge:
Some Matrox cards have composite sync and some don't. On my page, where it says " SOME Matrox Millennium Series (up to G200)", i asked a couple of friends who had done VGA monitor mods before (connecting a Sun Workstation monitor to a standard PC), and they said that Matrox Millennium cards up to the G200 have support for composite sync, so i put that on my page. If you find that Powerstrip's not letting you switch composite sync on, i'll make a note of that on my page, and you'll need to build a circuit like MatricPC's to get a composite sync signal.

VGA pins 4 and 11 should be tied to the VGA ground, which is actually pin 5 or 10 on the VGA connector. There are seperate grounds for Red, Green and Blue to improve signal integrity on a VGA cable, but with this mod they don't really matter because the resolution isn't that high in the first place. You could probably tie all the grounds together (pins 6,7,8,5,10 on the VGA to PSX pin 8 and to VGA pins 11 and 4).
See here for more info: http://www.epanorama.net/documents/pc/vga_bd15.html

Tying pins 4 and 11 to ground is in the VGA specification for detecting a monitor that supports 1024x768, though this doesn't work for a lot of video cards that use DCC instead. I don't think there's an easy way to implement DCC though short of a lot of I2C ICs which is way beyond me

**Mesuge** · 06-07-2004, 07:57 AM

Starfox> Thanks for your last piece on grounds..

Well, as I said I have no probs with going to the "arcade" mode and csync in powerstrip, but my lcd gets only green. I switched vga cables and the new one lacks the DCC pin (VGA pin #9) so I will have to start the display
by other means - how are you dealing with this issue?

I found a nice hack from a DIY projection freaks in Germany which is called "always on" and utilizes just one 300ohm resistor and single wire on the lcd pcb. I hope it will work for me because they are using mostly scart mods not vga..

These Psx lcd mods are courtesy of Metallhuhn, and Harald
More on scart&vga (resistor) mods and diagrams
+ Harald's less reddish hack & more brightness hack here:

http://www.diy-tronic.de/forum/viewtopic.php?t=644
http://www.diy-community.de

**starfox** · 06-07-2004, 11:24 AM

Ah i see what that's doing.. The PSOne takes a 7.5V input, but i remember that there's two paths for that: one goes to a 5V regulated power plane for the TTL circuitry, and the other goes to the flyback for the LCD backlit.

You could just find a 5V source with a multimeter, then solder across a wire link to the same track as the 5V Power On signal, and your display would always be switched on. I'll take a guess that's what they're doing and the 300 ohm resistor is a current limit so you don't blow up the sensing circuitry..

hehe those German guys sure like modding things and soldering to SMD components

That mod should work..