Anyone ever done an S-Video hack?

[adric22]

I have posted this on a few other forums.  So far nobody has responded, so I'm guessing it has never been done.

I think an Amiga 1000 should be able to run S-Video.  There is plenty of room on the back of the case for it, and I believe all the signals should be available.  I have been poking around and managed to find a good source for the luma signal, but not the chroma.   I have the schematic for the A1000 but it is a scanned copy of a hand-drawn schematic and it is a bit tough to follow.

I think this project can be done if there are some better experts out there.  It would make the Amiga 1000 far more useable on modern display devices.  I wouldn't even mind if I had to remove some component which would render the composite output inoperative (after all, it is easy to convert S-video to composite with an external cable)

I'd love to do the same thing to the A500, but studying the schematic I don't believe it is possible without additional circuitry.

[reddwarfer]

Aren't the required lines in the RGB connector?

[Tomas]

Someone posted here on amiga.org or amigaworld.net a guide to make the a520 modulator into outputting svideo instead of composite. This guide seemed simple enough if you have some soldering and some basic electronic skills. They also showed pictures of how it was done and also screen grabs for comparision.

Edit: http://www.amiga.org/forums/showthread.php?t=25836

The guide itself:
guide

[Zac67]

An extremely easy yet inexpensive way to get S-Video is to simply buy a second hand genlock - <$10 and most have pretty good output quality.

[James]

I know I have all the theory wrong here, but when I needed to hook up PC's S-Video output to my TV's run-of-the-mill video-in. I just connected both GND together, and both live wires together. Works like a charm.. not even a single interference in the screen, top quality. From the little I've read about it.. it seemed to say that S-Video is basically just the same signal, twice, so there's no signal loss. One is *slightly* different and you may need a small piece (cap, res... dunno) between the two lives if you have intereference.

So yes, all signals should be easy to find on the mobo.

In the Amiga community support ideas forum, I expressed the idea of making an Amiga RGB to component Y-Pb-Pr converter.

Somebody even gave a link to a schematic that is relatively simple and could work if realized properly.

When I first saw a large TV set display component video back in 1999, it was still interlaced video and the first thing that came to my mind is that this image was as clean and had colors as intense as the Amiga's display.

Even if the resolution of the image in S-Video is much cleaner compared to composite because the chroma isn't modulated with the luma in a single cable, it still doesn't have the wide color gamut that Y-Pb-Pr and analog RGB have.

Just about every new TV sets now have component Y-Pb-Pr inputs.

[Jope]

Here in Europe we have been able to enjoy YPbPr-level clarity from our TV sets since the 80s thanks to RGB SCART. ;-)

But yeah, make the converter.. Nowadays YPbPr is very common.

[Dr_Righteous]

Use a neobitz, it works great! http://www.neobitz.com/

[melange]

Your correct, the A500 doesn't have the required circuitry.  I can't speak for the A1000, but I have done the S-Video hack for two A1200's and one A600 and all of those work great.  A1200/600 has what's required, the signals are there.  However a small circuit still had to be built (I guess to drive the signal or somthing) in order for it to work.  The hack was copied from the CD32, which had S-Video built in.
I have also hacked an A520 Modulator to S-Video, which worked, but not very well for me.  I think I might have an incorrect value resistor in there somewhere, I will figure it out one day. :-)
The reason I believe I made a mistake, is that I have seen somewhere on this or another forum, that other people have succesfully made the hack, and it works well.

[adric22]

Yes.. I just looked at the link for the Neo-Bitz.  It looks like that would work great, and you are telling me you've already tried it and it does work.  So, that is awesome.  However, the order page doesn't work and I can't find a price.  I just emailed the guy who runs the site so I'm waiting for a reply.  if they are cheap enough, I might buy two of them.  one for my A500 and the other for my A1000.

[pVC]

This also works with A1200.. I don't know if other Amigas have same circuit...

http://www.mikeg2.freeserve.co.uk/masterful/rgb.html

[JMKurtz]

My first post to the Amiga forums...

First, let me introduce myself. My name is Jeff Kurtz. I'm an C64/Amiga fan -- not a fanatic, but a fan.

I build the Neobitz line of products. I generally use these for the Neo-Geo systems, but basically they work with many RGB/S sources...

I'm not familiar with what is inside an A500, 1000, 2000, etc., as I no longer have those machines, but the A600 & A1200 have the same video chip (Sony CXA1145) inside as the Neo-Geo and some Genesis systems.

There is a basic SVideo mod that I standardized for the Neo that others have used on the Genesis and such which should also work on the Amiga and is publiclly available.

I've never examined the Amiga A600 & A1200 to see if it has the necessary components to drive Y/C from the CXA, but if not (like the Neo & Genesis), you can build it up yourself. However, this isn't the most "optimal" solution as the CXA1145 is a rather mediocre encoder. It works, but it could be better.

This is why I developed the Neobitz products -- to get better picture quality ouf of the Neo via Component Video, but also get a better SVideo display too.

A note about the link above this post -- I just looked at that pic and that is not a good mod to drive SVid from the CXA. It could overload the luma line and cause the picture to go bright on some TV sets. The picture could bend out, or your TV may loose sync, or something along those lines...  Try it on a very bright screen -- something with a white background... One thing about hacking video -- what may work on one TV may not work on another.


Jeff

[nyteschayde]

Well Jeff, if what you say is true and it works, you could stand to make a decent profit selling assembled converters to Amiga users. Price them low and they will sell like hot cakes. Especially if you can find a way to provide component video output.

Provide us with an amiga video port input (if needed) and or a composite video port, and we can provide all the pin schematics for all the Amiga models released.

Give us s-video and hopefully component video and you've got a hot seller. Add SCART output for all those blokes in the UK and you've got quite a bit of money coming in.

The biggest problem for us right now is that all the video converter solutions that let us break away from 15Khz monitors/televisions are over a hundred dollars. Most of us settle for hacking an A520 or using composite video unless we have a built system using RTG.

I can't speak for them, but even though I have a really nice setup I would happily pay for a adapter that gave me quality s-video and especially component video out for my Amigas.

Gabriel

[adric22]

Yep.. I think I am going to get one of these boards and try it out.  

Yes.. the Amiga 1000, 500, and 2000 all could benefit greatly from this.  In fact, I kind of look at it like this.  You can buy a 15" flat-screen LCD TV these days for cheap.. around $150 to $200.  It will probably have a component input and definatly have an S-video input.  I am pretty sure that if you had a good quality S-video from the amiga, then this setup should give you results at least as good as the original 1084.. If you had the component connections, I'm pretty sure it would probably be superior to the 1084.  This would allow the classic line of Amigas to be used with a modern video display.

[Dr_Righteous]

@JMKurtz

See? I told you there'd be interest.

@adric22

Yes, I have tried Neobitz with both an A500 and A4000. It works great! You must connect it directly to the video connector, do not use the VGA adapter as it messes with the sync.

See this thread