PS1 to crt (vga) monitor

misjah · Post by **misjah** » Wed Dec 10, 2008 8:13 pm

Hi, I found a bunch of schematics for converting rgb signal from various consoles, people say it`s working but I can`t make my to work.
I used one with IC lm1881 and the one with 7404 and tried with 2 monitors. Both monitors display message ``out of range`` and the picture is all messed up. Problem is always with horisontal frequency - to low or to high. Here`s the schematic I used:

goodie · Post by **goodie** » Thu Dec 11, 2008 6:03 pm

I could be wrong, but I believe that is for 15khz RGB. Most newer monitors use a 31khz signal and won't work with 15khz.

Post by **marshallh** » Thu Dec 11, 2008 7:06 pm

That's for the PS2. Different video hardware.

The PS1 outputs 15KHz RGB - you won't get it to show up on any monitor unless you run it through a scan doubler, or use a multisync monitor.

misjah · Post by **misjah** » Fri Dec 12, 2008 9:07 am

That`s right, monitor detects about 14-15 KHz or higher than 100 KHz which is out of limit.Thanx for the info guys. Is this same for SNES and N64 or any other older console that supports rgb out?

tom61 · Post by **tom61** » Fri Dec 12, 2008 3:24 pm

misjah wrote:That`s right, monitor detects about 14-15 KHz or higher than 100 KHz which is out of limit.Thanx for the info guys. Is this same for SNES and N64 or any other older console that supports rgb out?

Yes. The oldest you can go and still get VGA is Dreamcast.

Kyo · Post by **Kyo** » Sat Dec 13, 2008 4:03 am

isn't there some kind of IC that would take care of this?

grossaffe · Post by **grossaffe** » Sat Dec 13, 2008 4:14 am

tom61 wrote:
misjah wrote:That`s right, monitor detects about 14-15 KHz or higher than 100 KHz which is out of limit.Thanx for the info guys. Is this same for SNES and N64 or any other older console that supports rgb out?
Yes. The oldest you can go and still get VGA is Dreamcast.

what? you mean I couldn't hook up an SNES to a monitor?

tom61 · Post by **tom61** » Sat Dec 13, 2008 3:36 pm

grossaffe wrote:what? you mean I couldn't hook up an SNES to a monitor?

Unless it supports a scan rate of 15kHz horizontal refresh rate, no, not directly at least. You'd end up with a blurring screeching mess, unless you have one of the monitors that sync that low. 640x480 at 60Hz vertical refresh rate is ~31kHz horizontal refresh rate, so most newer PC monitors don't sync low enough to handle 15kHz input.

Kyo wrote:isn't there some kind of IC that would take care of this?

There probably is a single chip solution now, the universal VGA box that I had (V-Box) used two chips, but that is a few years old. You'll need a scan-doubler that takes in analog RGB, or other console output.

misjah · Post by **misjah** » Sat Dec 20, 2008 3:52 pm

This is happening with tv too, both tv and sony are pal....