Help needed: VGA to TV

[Vertigo]

Aloha!

Probably already been covered, but I'm lazy and couldn't find anything from 23 seconds of searching. Darling Lawrence will beat me for that.

How might one go about getting the signal from my PC graphics card to be happily compatible with my TV?
I have a video card capable of TV out, but I want to tap RGB signals instead of the usual composite shit-fest if at all possible. This would possibly involve changing the horizontal sync, no? Or is it possible to make a combination cable bearing in mind that my video card appears to disable VGA out when TV out is active. It does appear to have a DV out socket too, although my TV is of the standard 480i variety (with composite and RGB SCART in).

I'd also need to know if anyone can advise me on where to buy ready-made sound cable from 3.5mm jack to RCAs that measures 15 metres in the UK, or will I have to buy cable and make my own? If I used a cable extender or three, would the signal really degrade significantly so as I'd notice? Bearing in mind I'm not a Blu-Ray-owning DVD technocrat twat, I just want to be able to watch any PC file or play a PC game from the other room on the TV instead of on the PC and don't have any way to multimediafy things like a chipped XBox or whatever.

Apols for any inclarity (new word?) of the post, I've been drinking and have just remembered this so needed to post it ASAP before I forgot.

Cheers!

[Barkuti]

For your computer's signal to be compatible with standard TV modes, you need to make your graphics card to output modes in ~15.7 KHz horizontal scanrate. Best software to manage this (not free tough) is the popular PowerStrip. Non registered versions still let you create custom resolution modes which will remain defined upon uninstallation.

You will have to make a Sub-D15 to SCART cable. Strip a standard SCART cable and replace one of the males with the Sub-D15 one. Or build a new one from scratch; I recommend using CAT5 FTP (Foil-Twisted Pair) network cable, the shielded variety, if you opt for this way. I once made one and the quality is stunning, not to say you can run very long distances with it without a noticeably loss of quality and, hey, it's cheap.
There's a lot of info on this subject on the web, just google a bit.

Don't forget you'll have to combine the sync signals if your graphics card won't like to output composite sync (circuit required); but by keeping both sync polarities negative you may just join both sync lines and most TV's will just swallow it straight.

Also, power will need to be given to blanking pin (16), 1-3 Volts (75 Ohms impedance). A 100 Ohm resistor will do fine on a 5 V supply, or a 330 Ohm one for 12 V. Or a rechargeable battery.
Oh, mmm, I once made a dirty cable for testing which I ended up using a lot cos it worked very well. The cable had H+V syncs joined and I put this same signal over pin 16. It worked. ROFL. Tested on maybe 7-8 TVs with very little issues; one just showed a greenish tint picture, other just didn't wanted to turn off the "AV" OSD message at first. The rest, just perfect. B)
I warn you, this ultra-easy method could be considered "very dirty", tough.

May this help you.

Cheers

[viletim]

If take the video from the VGA connector, consider my Dodgy Diode circuit. It's infinately better than wiring the two sync signals together.

Long audio cables shouldn't give any problems...a long cable with phono sockets on each and and a little 3.5mm jack adaptor is all you need.

BTW I bought a Radeon 9200 video card the other day. It's got a 7 pin mini din socket in place of the usual four pin socket for s-video output. Aparently it can spit out both composite and s-video at the same time. Nothing to special about that, but there is an option on the Rabit Radeon bios twiddling software to set these three DACs to output RGB instead of Y, C, and V. I've also heard of Matrox cards with a simlar setup...

[NeWmAn]

Viletim: I'm not sure if your card is compatible, but most ATI 92xx cards can use an hacked ArcadeVGA BIOS which gives you 15KHz output without the need to use Powerstrip or other tools.

[viletim]

ni something...,
Yeah, I know

[Barkuti]

Hi guys,

Just found this browsing the BYOAC forums: Soft-15KHz - slim new tool for 15KHz on normal vga cards

No need to mess with PowerStrip or hacked ArcadeVGA bioses. Plug & Play. Quite a handy tool!

Cheers