VGA output from ATI laptop to composite RCA

[freeztar]

I purchased a device similar to this one:
http://cgi.ebay.com/NW-VGA-SVGA-to-S-Video-3-RCA-computer-to-TV-Cable-S-vid_W0QQitemZ270335587468QQcmdZViewItemQQptZPCA_Ca bles_Adapters?hash=item270335587468&_trksid=p3286. c0.m14&_trkparms=72%3A1234|66%3A2|65%3A12|39%3A1|2 40%3A1309|301%3A0|293%3A1|294%3A50

I plugged it into an old HP laptop with an ATI Radeon mobility M7-C via VGA output. Under the display tab of the ATI settings, it shows the TV-out, but shows it an disconnected. I rebooted and still the same result.

Is there some special software that I need to make this work? What am I doing wrong? Any help is greatly appreciated!!

Thanks in advance!

[redwudz]

It states in the ad:

It will work with laptops and desktops with VGA cards that has TV-Out function capability through the VGA connector.

That's just a adapter that uses the VGA output socket which must already have a composite output. Maybe yours doesn't. It's not a converter. The other possibility is that the adapter uses the wrong pins.

Also, most times, you would have to plug in the external monitor and have it on before powering up the PC for the software to detect the monitor.

I would check the laptop manual and it should indicate if you already have composite output via the VGA socket. Most laptops I have used have composite out through a seven pin DIN S-video socket.

And welcome to our forums.

[freeztar]

Thanks for the response and greetings!

The ATI Radeon mobility card that is in the laptop does have an S-video out. Apparently it is enabled via the "HP TV Now" prog that came pre-installed. I guess this means that the *only* tv-out capability this graphx card has is through that port and not the VGA adapter? If so, then I guess that means I wasted my money.

Out of curiousity, what sort of card has a VGA to Composite RCA TV-out without having the S-Video out? From what you are saying, it seems that this adapter is good only for such cards.

[edDV]

Thanks for the response and greetings!

The ATI Radeon mobility card that is in the laptop does have an S-video out. Apparently it is enabled via the "HP TV Now" prog that came pre-installed. I guess this means that the *only* tv-out capability this graphx card has is through that port and not the VGA adapter? If so, then I guess that means I wasted my money.

Out of curiousity, what sort of card has a VGA to Composite RCA TV-out without having the S-Video out? From what you are saying, it seems that this adapter is good only for such cards.

I've never seen a card with composite, S-Video or audio added to the VGA. There aren't enough spare pins in a VGA connector, only two. It might be for a game system.


http://en.wikipedia.org/wiki/VGA_connector

[jagabo]

I've never seen a card with composite, S-Video or audio added to the VGA. There aren't enough spare pins in a VGA connector, only two.

There were originally several unused pins on the VGA connector. I don't think any s-video-via-vga cards have been produced since four of the unused pins were reassigned by VESA for monitor ID. Sellers of those adapters prey upon people who don't read or understand the consequences of the fine print.

[redwudz]

Looking at that ad again, that does look like some sort of game adapter. It has a red and white (Audio?) RCA jacks, beside the composite and possibly a S-video jack. Or it may just be for a particular video card. I don't think it plugs into a actual VGA socket, just a socket that looks similar.

If you do have a seven pin S-video jack on the laptop, a adapter shouldn't be hard to find. Some ATI cards use 8 pins also. Several of the ATI PCI cards I have came with the composite adapter. There are also converter adapters that use just the 4 S-video pins.


This one is $.84 at Monoprice: http://www.monoprice.com/products/product.asp?c_id=104&cp_id=10401&cs_id=1040105&p_id=...seq=1&format=2

A view of a ATI 8pin S-video>Composite adapter



You would have to run the audio separately, with a 1/8" stereo plug to RCA jack adapter. Fairly common.



You may be aware that composite out is not a very good picture. It will probably be OK for video, but computer text will be very hard to read.

[freeztar]

Thanks so much for the info everyone. I wish I had come here before I bought the useless adapter.

You may be aware that composite out is not a very good picture. It will probably be OK for video, but computer text will be very hard to read.

Yeah, that's what I've been reading. The S-video via HP TV Now should be a good enough picture for text though, right? I'm still having trouble finding a good cable though. Something like this would be great:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&item=260352632307

Except that cable has a 4-pin svideo and I need a 7-pin...

[edDV]

Is your TV old?

If you have a VGA input on the TV use that.

S-Video will be poor for text ~500x480i to 640x480i. Look at how they handle text on cable TV. Answer is huge sans serif fonts.

This is about the best you can expect (has sharpness turned up). This was a capture from the S-Video out.

[freeztar]

Is your TV old?

The one I'm using right now is fairly old (~15 years) and only has composite RCA and S-video as inputs.

If you have a VGA input on the TV use that.

My wife has a newer tv in storage which we will be setting up this week or next. I think it has a VGA input, but I'll have to wait until we set it up to be sure.
Isn't there a limit on how long of a VGA cable you can use? I was hoping to be able to run a long cord across our living room so that the laptop can be accessed on the sofa.

S-Video will be poor for text ~500x480i to 640x480i. Look at how they handle text on cable TV. Answer is huge sans serif fonts.

This is about the best you can expect (has sharpness turned up). This was a capture from the S-Video out.

Well, that's not terrible, but it's not great either. As long as I can run a ~20' cable, then I'll probably go with the VGA.

[edDV]

20 ft. will work for VGA.

Best to buy a double shielded cable.
http://www.monoprice.com/products/product.asp?c_id=102&cp_id=10201&cs_id=1020101&p_id=...seq=1&format=2

[redwudz]

The four pin versions of the adapters just combine the S-video pins together to arrive at a composite output. I don't know that the final output is different, but 7 (Or 8) pin versions take the composite signal directly from the video card, no combining.

Sorry that this is a bit convoluted, but different cards use different methods of arriving at a composite output. If your TV has a better selection than just composite, but all means use it. VGA or S-video is a big step up from composite for video display.

[ajkerr]

Let's not all get so excited about this being impossible without being informed about the graphics card in question please. This shows that it is possible on recent ATi cards http://www.touchsmartdevzone.com/forum/thread/1099/S-video-hack/

[edDV]

So did you get it to work? On which card?

Ryano and loociddreemr never came back to say they got it to work.

[ajkerr]

I just got the cable today - haven't got color working yet on s-video, maybe it is stuck in hd-tv mode - as the post suggested that this makes the output black and white. I haven't tested extensively. I'm using an ATI HD 3200

[edDV]

For this to work, ATI would need to switch Y and C onto those pins on the VGA connector. It would be a proprietary modification to the VGA spec. I can't find any ATI documentation that mentions this.

ATI did something similar in the past with a proprietary adapter that passed analog Y, Pb, Pr over the VGA RGB pins. A separate model did the same for their custom DVI-I connector. This mod was well documented. They only worked with selected 8xxx/9xxx AIW/Radeon cards, not laptop chipsets.

http://ati.amd.com/products/hdtvadapter/specs.html
http://ati.amd.com/products/hdtvadapter/gallery.html





The Dip switches set RGB or Y,PbPr 1080i, 720p, 480p, 480i out.

They show nothing about S-Video from a VGA pinout.