Author Topic: PSone (NTSC/U) VGA/RGB output - no green?  (Read 9517 times)

Offline sarelc

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PSone (NTSC/U) VGA/RGB output - no green?
« on: August 06, 2008, 07:08:18 pm »
Hi guys. It was a rainy day today so I decided to get working on a project... building a simple VGA cable for my old PS1 (SCPH-101). I used a monitor cable for the VGA end, and a combo XBox+PS2 Component cable that I got at a second hand store for the AV connector. After planning/cutting/soldering/checking, I powered it up... No explosions, but no green in the image, either. I tested it on an old Samsung SyncMaster monitor and the output was solid (but displayed incorrectly, the image was stretched horizontally and overlapped itself). Then moved on to my Epson HC720 LCD projector, where this was meant to end up - the image is sized/centered properly, but still no green. I checked the wiring again, there's continuity from the VGA pin all the way to the solder hole under the PS1's AV connector socket. This is such a dead-simple mod I don't know what to do next! The info I can find online about it is all aimed at SCART devices though, so it makes for pretty confusing reading. This is a short rundown of what I'm doing, just in case I've misunderstood something.

Pin Chart:
Code: [Select]
   PS1 | VGA
   .----------
R  |11 | 1
G  |12 | 2
B  | 9 | 3
GND| 8 | 6,7,8
H-S| x | 13
V-S| x | 14
The H-Sync and V-Sync are respectively being pulled from pins 159 and 158 on the CXD8561CQ chip, as per the instructions on the gamesx.com wiki. Here are some questions that may be relevant:

1. The North American PSone does output RGB and not component, right? I was thinking that might have something to do with the green missing.
2. Do I need the composite sync for anything? VGA should also be able to use C-Sync on pin 13, but I don't see why it should need it since the sync is currently fine (and C-Sync would require extra parts since this model doesn't output it)
3. Could the pinout for the PSone be incorrect?
4. I see references to using 220uF capacitors on each colour line, in regards to brightening the output - but again that seems to be referencing SCART, and it doesn't appear to be dark at all (unless the green is dark enough to be invisible!), would adding these caps improve anything?

Thanks for reading, please pass along any suggestions...
« Last Edit: August 08, 2008, 04:03:05 am by sarelc »

Offline ニユ-マン

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Re: PSone (NTSC/U) VGA/RGB output - no green?
« Reply #1 on: August 06, 2008, 09:00:37 pm »
Hi,
Try to switch 2 of the points where you have soldered the R,G,B wires; for example switch R with G.
If you get red but keep missing the green then there's a problem with your wiring/monitor.
If you get green but miss the red there's a problem with your video chip, or you have soldered on the wrong point.

1. The North American PSone does output RGB and not component, right?
right
Quote
2. Do I need the composite sync for anything?
Not if you keep using the separate H & V


Offline sarelc

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Re: PSone (NTSC/U) VGA/RGB output - no green?
« Reply #2 on: August 07, 2008, 04:09:33 pm »
Hmm. Well, problem solved, but no idea why. I checked all the connections from one end of the cable to the other before I started on it again, and continuity/resistance were fine. Desoldered the green/blue cables and reversed them, and it was working normally (except for the colors being wrong, naturally). Set it back the way it was, and now it's working perfectly. I guess it could have been a cold solder joint, but hopefully I won't find out. Now I just have to fix the mistake with the audio.   ::)

Thanks for your suggestions and info ニユ-マン.

Offline archenemy666

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Re: PSone (NTSC/U) VGA/RGB output - no green?
« Reply #3 on: August 29, 2008, 07:00:22 am »
omg, do you make an vga output in ps1?  ???
please show some screen and info

Offline ken_cinder

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Re: PSone (NTSC/U) VGA/RGB output - no green?
« Reply #4 on: September 03, 2008, 09:31:24 am »
omg, do you make an vga output in ps1?  ???
please show some screen and info

Many of the old Syncmaster monitors support 15khz over the VGA port. 31khz VGA from the PS1 would require something like an XRGB.

Offline Ocelot85

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Re: PSone (NTSC/U) VGA/RGB output - no green?
« Reply #5 on: May 25, 2009, 08:07:05 pm »
I'd really like to try this mod but the component cable for my PS2 doesn't fit my PS1, I thought PS1/PS2/PS3 AV connectors are all the same shape.

Does this also work on PAL models(would I be able to adapt this to a PS SCART cable?), and how come the PS1 would be outputting 31khz?
« Last Edit: May 25, 2009, 08:09:59 pm by Ocelot85 »

Offline Lawrence

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Re: PSone (NTSC/U) VGA/RGB output - no green?
« Reply #6 on: May 25, 2009, 09:52:52 pm »
I'd really like to try this mod but the component cable for my PS2 doesn't fit my PS1, I thought PS1/PS2/PS3 AV connectors are all the same shape.

Does this also work on PAL models(would I be able to adapt this to a PS SCART cable?), and how come the PS1 would be outputting 31khz?

The PS1 doesn't output component video, only RGB.  That said, I didn't think any of the cables/connectors were different, so this is a surprise.  Are you sure you've got it the right way up?  ;)

Offline Ocelot85

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Re: PSone (NTSC/U) VGA/RGB output - no green?
« Reply #7 on: May 25, 2009, 10:37:02 pm »
It definitely does not fit the AV port on either my SCPH-1002 or SCPH 7502, but it fits my PS2 and PS3 perfectly.

The box said it is a PS3 component cable, every pin on the connector seem to be present.  All of my composite cables are inter-changeable.
If you have a PS3 component cable could you please try it a PS1 (assuming you have one)?

I'll try it on my PSOne (SCPH-102) tomorrow as I don't have it with me right now, I'll also see what  I can do about obtaining a 5XXX model.
« Last Edit: May 25, 2009, 10:53:01 pm by Ocelot85 »

Offline Ocelot85

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Re: PSone (NTSC/U) VGA/RGB output - no green?
« Reply #8 on: May 26, 2009, 04:42:24 pm »
I tried it in the PSOne (102) and I got it to fit but it wasn't easy. Now the cable also fits the SCPH-7502 but it was a very tight squeeze (story of my life ;D ).

Offline juanmiglesias

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Re: PSone (NTSC/U) VGA/RGB output - no green?
« Reply #9 on: May 23, 2017, 04:40:44 pm »
HI guys I have been researching a bit on the SCPH-101 (mini) and almost every site says it doesn't output csync.
actually pin 156 on the gpu does output csync which goes up to the rgb chip. It is on the schematic for the console btw.

I just try it on my nec xm29plus with no issues. (it takes sync as TTL or terminated inputs)

here is a little diagram I did.