Catbox/Scatbox VGA to HDTV

[Rick Dangerous]

This has sort of been touched on in other threads bot not really. The only reason I would be interested in getting a catbox is because of the ability to get red green blue separation which would improve picture quality quite a bit, eliminating color bleeding.

 

I already have two sets of Composite cables, and am thinking of just getting a few jag links depending on this question:

 

Can you take a standard VGA cable and plug your catbox or Scatbox into a modern HDTV running at 60hz or 120hz and get a high quality RGB separated, 480p picture? I don't have interest in playing my jag on old 80's computer monitors, cool as that idea is.

 

If the answer is no, based on the Catbox manual it looks like you could have a local electronics shop rig up a special cable for you? Or is that not even a possibility?

 

Would love to get 480p out of the jag... I bought the component cable for my GameCube and it makes a world of difference...

 

Thanks!!

[jmetal88]

There's a chance you might find a TV that'll display it, but it's pretty slim and it's definitely not going to be a 480p signal. What the Jag is putting out over RGB is a 240p-over-480i video signal with a horizontal refresh of 15kHz. A VGA port will expect a 480p signal with a 30kHz horizontal refresh. Also, you might have issues getting the sync signals out properly.

[Rick Dangerous]

So basically there is no reason to get a catbox unless you are a developer, or want to display on an old computer monitor?

 

Otherwise a few composite cables and two jag links will do the same trick..

Edited February 15, 2014 by travistouchdown

[racerx]

Or you want to network your Battlespheres or Air Cars.

[jmetal88]

Or you want to network your Battlespheres or Air Cars.

 

 

I was just about to say the same thing, although where I live there's so little interest in the Jaguar that even that doesn't make much sense as a reason to buy a CatBox.

[Rick Dangerous]

Or you want to network your Battlespheres or Air Cars.

I was about to go back and say the same thing. 8 to 16 players would be cool for sure. Except I imagine the only time you get that many copies of two unobtainable games and that many cat boxes together is at a Jagfest event...

 

Pity I was really hoping to get some RGB separation. 480p is a world of differene over 480i.

 

Okay jag links it is... If i can't do 480p i dont see reason i'd need more than composite cables. Other than a better picture I just want to play doom on two TV's with a friend.

[Gunstar]

So basically there is no reason to get a catbox unless you are a developer, or want to display on an old computer monitor?

 

Otherwise a few composite cables and two jag links will do the same trick..

It's easier and less expensive to build or have built your own custom RGB cable, like I did, since Catboxes/scatboxes are so very expensive. What I did was I bought bought this: http://www.ambery.com/rgbcgatovgac.html

This will upscale to 480p 30KHz VGA.

 

There are of course other brands of similiar upscaler/converters, and outputs can be VGA, Component, DVI or even HDMI, though a lot are quite pricey, starting at about $60 for some questionable models all the way up to several thousand dollars.

 

The Ambery is about $90, and it does require a custom cable to input to the converter (standard VGA out) with the Jag connector at one end and the input on the converter uses a standard VGA 15-pin plug (like the Jaguar controller ports too). I would be happy to offer my services in making the cable, I actually have most parts and the shielded cable on hand (I would only need to order the edge connector for around $5 from Digi-key or similiar electronic component store. I would display a picture, but my camera's memory cards are missing, however, I did post pics years ago on this site, IIRC, if I can find the thread I'll post a link here.

 

the catbox/scatbox can use something like the Ambery converter too, but you would still need a custom 9-pin to 15-pin cable made to connect to the converter, so it's much cheaper just to build a cable made for direct connection to the Jaguar.

Edited February 15, 2014 by Gunstar

[+madman]

Making your own RGB cable is one way to go and converting that, or an S-Video cable would be an easier option and give you better video than composite, but of course not as good as RGB. The Gamecube quality can't really be equated to the Jag, as the Gamecube natively outputs at 480p, as mentioned the Jag doesn't. Though there is one particular person who is convinced his Jag outputs a 1080p signal, but that's another story

[Zerosquare]

100% of the official games, and almost 100% of the homebrews, output 240p (those which don't use 480i).

 

If you want the best video quality (significantly better than composite), you need to use the RGB outputs. The cheapest way is to buy (or build) a SCART cable.

 

- if your TV set has a high-quality SCART input that supports 240p (unfortunately, it varies a lot from model to model), you're done.

 

- if it doesn't, but has a high-quality YPbPr input that supports 240p, all you need is a RGB->YPbPr transcoder (they're pretty cheap) with appropriate cables.

 

- otherwise, get a good RGB-to-HDMI transcoder.

 

I wouldn't recommend VGA transcoders, since it adds an intermediate conversion step.

[Gunstar]

my RGB to VGA converter has worked flawlessly for years and is absolutely brilliant. Regardless of the extra step, it works fantastically with an incredible picture, and you can set output at 640x480p, 1024x768 and even WXGA 1280x960, the difference mainly being sharp-edge pixels or softened pixels. It doesn't have color/bright/contrast controls, but that doesn't matter as my monitors and projector do have them. The 480p upscaling is fantastic and is far better than 240p because all the skipped scan lines are filled in, giving the picture a much more vibrant, sharp and colorful look than 240p. Though, as I said, you can also get RGB to HDMI/DVI or component converters (ambery has them all, as well s other brands out there) so whatever your TV or monitor has for inputs, you can enjoy 480p on the Jaguar; it's also a must for projectors like mine, 240p look terrible with a 150" screen, the empty scan lines can be awful to look at. If you have a small monitor it's not as noticeable, but, 480p still looks sharper and more colorful even on my small monitors .

 

I do have an older wide-screen HD TV that only uses 480i, 480p or 1080i and the best input is DVI (older version of HDMI, but just as good) so I'm planning on getting a Jaguar RGB scart cable and buying Ambery's Scart rGB to DVI convert box for that TV. It will also upscale to 480p.

Edited February 15, 2014 by Gunstar

[Zerosquare]

I'm not saying you can't get good results with a VGA transcoder, I'm saying a HDMI converter makes more sense and will probably give a higher quality.

 

And we've already discussed the 480p thing. If your source is 240p, converting it to 480p won't improve the picture at all. On a CRT screen that supports both (most don't), it may make the scanlines less visible, but that's all. On LCD and plasma screens, it won't make a difference. 480p converters exist because some screens (almost all VGA monitors for example) don't support 240p and 480i.

[Rick Dangerous]

Very very interesting and I appreciate the input from everyone.

 

I have YPbPr input or VGA... So I need a 9 pin RGB to whatever fits into a YPbPr or HDMI transcoder. Then VGA Cable into the TV?

 

 

What is the appropriate transcoder..This?

 

http://www.ebay.com/itm/Brand-NEW-MDA-RGB-CGA-EGA-to-VGA-industrial-Converter-/250851103017?pt=US_Video_Cables_Adapters&hash=item3a67e41129

 

Seems expensive? Or this sucker: Which Gunstar originally recommended but may be not putting out native 240p?

 

http://www.ebay.com/itm/15Khz-RGB-RGsB-RGBS-to-VGA-XGA-Converter-Scaler-/350497862833?pt=US_Vintage_Computers_Mainframes&hash=item519b4cf4b1

 

 

 

Man I think I bit off more than I can chew..

Edited February 15, 2014 by travistouchdown

[Rick Dangerous]

the catbox/scatbox can use something like the Ambery converter too, but you would still need a custom 9-pin to 15-pin cable made to connect to the converter, so it's much cheaper just to build a cable made for direct connection to the Jaguar.

 

Thanks for the offer I might take you up on that. The Ambery is looking like a winner that will get me a little better than S-Video Picture quality. What would the cable look like? Would you use a stock jag composite cable plug that turns into a 15-pin VGA? And that would get the native RGB out of the system?

 

Thanks! Sorry to make this such a headache, I just always like to squeeze the best pictures out of my consoles if I can....

[Gunstar]

I'm not saying you can't get good results with a VGA transcoder, I'm saying a HDMI converter makes more sense and will probably give a higher quality.

 

And we've already discussed the 480p thing. If your source is 240p, converting it to 480p won't improve the picture at all. On a CRT screen that supports both (most don't), it may make the scanlines less visible, but that's all. On LCD and plasma screens, it won't make a difference. 480p converters exist because some screens (almost all VGA monitors for example) don't support 240p and 480i.

It will give the same quality, not higher.

 

Converting to 480p gives a MUCH improved picture because every other scan line is no longer skipped, why is it so hard for people to understand this?!? I KNOW from side-by-side testing, observation and experience! The difference in noticing scan lines between 240p and 480i or 480p is HUGE, unless you are using a 13 inch screen!

 

Yes, Plasma and LCD screens it doesn't make a difference because they don't display with the traditional scan lines that CRT monitors do, they work with "cells," but, there is still a difference in color sharpness and saturation, no blurred colors.

Edited February 16, 2014 by Gunstar

[Gunstar]

 

Thanks for the offer I might take you up on that. The Ambery is looking like a winner that will get me a little better than S-Video Picture quality. What would the cable look like? Would you use a stock jag composite cable plug that turns into a 15-pin VGA? And that would get the native RGB out of the system?

 

Thanks! Sorry to make this such a headache, I just always like to squeeze the best pictures out of my consoles if I can....

It's more than just a little better than S-video, your taking 240p and making it 480p (the game resolution is the same, but the scan lines are doubled so there are no empty black scan lines every other scan line) which naturally improves color saturation sharpness because half the scan lines on the TV/monitor are no longer black. The cable will have an edge connector like the original atari composite cables at one end and the proper 15-pin vga connector at the other to plug into the Ambery converter, then, standard 15-pin VGA cable is used on the Ambery's output side. I wish I could show you a picture of mine, but I can't take pictures ( I lost my cameras SD cards and haven't gotten new ones yet). It will look professional, no exposed wires or plugs without cases. I used top quality shielded VGA cable,of which I have a 25ft. roll. It has 15+shielded wires going through it. It's professional grade cable superior to any VGA cable you'd buy from Walmart or Best buy. The audio out will be separate RCA L/R plugs that split off of the other end of the cable where the VGA plug is, so it will be an edge connector to the jag at one end and a 15-pin VGA plug and two RCA audio plugs at the other end. I can make the RCA audio plugs as separate cables coming off the Jaguar connector end if you need to run them separately to audio devices away from the TV/monitor.

Edited February 16, 2014 by Gunstar

[Zerosquare]

Converting to 480p gives a MUCH improved picture because every other scan line is no longer skipped, why is it so hard for people to understand this?!?

Because it's wrong?

 

LCD and plasma monitors don't have "empty", "black" or "skipped" scan lines in 240p mode. They don't even physically have any scan lines at all. The number of lines they show is determined solely by the LCD panel resolution; input signals are digitally resized to fit, and all lines are used.

 

If the picture looks sharper and with better color, it's because you're using a RGB output instead of a composite one. It's got nothing to do with 480p vs 240p. An CRT RGB monitor using 240p would give you a very sharp picture with great color, too.

[Gunstar]

Because it's wrong?

 

LCD and plasma monitors don't have "empty", "black" or "skipped" scan lines in 240p mode. They don't even physically have any scan lines at all. The number of lines they show is determined solely by the LCD panel resolution; input signals are digitally resized to fit, and all lines are used.

 

If the picture looks sharper and with better color, it's because you're using a RGB output instead of a composite one. It's got nothing to do with 480p vs 240p. An CRT RGB monitor using 240p would give you a very sharp picture with great color, too.

First, do a better job of reading my post, I said LCD and plasma are different, just like you said, second, it's not wrong regarding analog CRT screens, third, on analog CRT screens the sharper and better color is enhanced further than RGB because there are no skipped scan lines. I wasn't wrong, you just are either bad and reading comprehension, or, you failed to read my entire post before deciding to reply.

[Zerosquare]

travistouchdown : I don't use any myself, but I've looked at the prices and it appears than SCART->HDMI converters have gone down in price so much than simple RGB->YPbPr transcoders are no longer an attractive option (since there's the risk than your TV set won't support the 240p signal).

 

One model that is said to be compatible with 240p input signals, that should work with all TV sets, and has a reasonable price is this one:

http://www.ebay.com/itm/130660124088?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

 

To use it on a Jaguar, you'll need a SCART cable too:

http://atariage.com/forums/topic/189541-jaguar-scart-cable/

[Zerosquare]

on analog CRT screens the sharper and better color is enhanced further than RGB because there are no skipped scan lines. I wasn't wrong, you just are either bad and reading comprehension, or, you failed to read my entire post before deciding to reply.

Nope, sorry. You're still wrong.

 

On a CRT screen, all you may get by using 480p instead of 240p are less visible scanlines. It won't make the picture any sharper or the colors any better.

 

On a LCD or plasma screen, you won't gain anything at all.

Edited February 16, 2014 by Zerosquare

[Rick Dangerous]

Zerosquare: your counter-point has been awesome and I really appreciate the input. I'm NTSC so unfortunately the scart conversion won't work. I think the us closest equivalent is component (YPbPr)

 

Gunstar: Really stoked and flattered by your offer. What's my cost out the door? Message me with details if need be.

[jmetal88]

Zerosquare: your counter-point has been awesome and I really appreciate the input. I'm NTSC so unfortunately the scart conversion won't work. I think the us closest equivalent is component (YPbPr)

 

Gunstar: Really stoked and flattered by your offer. What's my cost out the door? Message me with details if need be.

 

An SCART to HDMI converter will work fine on an NTSC TV. I have one. Don't buy the one I bought though (CVID or its clones), it does some funny multi-frame image processing and introduces lag.

[jmetal88]

travistouchdown : I don't use any myself, but I've looked at the prices and it appears than SCART->HDMI converters have gone down in price so much than simple RGB->YPbPr transcoders are no longer an attractive option (since there's the risk than your TV set won't support the 240p signal).

 

I'd still prefer the RGB->YPbPr transcoder for my own purposes, although I don't even know if my own TV supports it. I've actually got my own design for one drawn up now that I'm starting to understand op amps better (I'm an Electronics Engineering Technology student) that I hope will be really cheap to produce. It looks like I may be able to built it with about $20 in parts.

 

EDIT: As for why, it's simply because with all analog components in the signal path, there's no chance of introducing lag.

Edited February 16, 2014 by jmetal88

[Zerosquare]

You can certainly build one yourself. It's not very complicated, just a bunch of precision resistors and high-bandwidth opamps :

http://www.linear.com/solutions/1312

 

Points to keep in mind if you want to design it from scratch:

- equivalent input impedance for R, G and B and sync/composite video must be about 75 ohms

- for devices using composite video instead of pure sync, sync must be separated using a sync stripper (LM1881 for example)

- the opamps must be able to supply enough current to drive a 75 ohms load (or 150 ohms if using a 2:1 gain and a series 75 ohms resistor)

- the opamps must have enough bandwidth (at least 10 MHz at the gain you're using)

- if you're using a single supply (non-symmetric), the input caps must be large enough (several hundreds of µF)

Edited February 16, 2014 by Zerosquare

[mckafka99]

So with the Jag, will the Catbox + the Ambery device + the special Ambery Cable they mention on the same page get the Jag directly connected to a typical VGA computer monitor? Is the display difference noticeably better than s-video? Thanks.

[jmetal88]

You can certainly build one yourself. It's not very complicated, just a bunch of precision resistors and high-bandwidth opamps :

http://www.linear.com/solutions/1312

 

Points to keep in mind if you want to design it from scratch:

- equivalent input impedance for R, G and B and sync/composite video must be about 75 ohms

- for devices using composite video instead of pure sync, sync must be separated using a sync stripper (LM1881 for example)

- the opamps must be able to supply enough current to drive a 75 ohms load (or 150 ohms if using a 2:1 gain and a series 75 ohms resistor)

- the opamps must have enough bandwidth (at least 10 MHz at the gain you're using)

- if you're using a single supply (non-symmetric), the input caps must be large enough (several hundreds of µF)

 

All good points, which I could have used a couple of years ago, but I've taken all those into account (well, except the output current) in my current design. The design I have works well in LTSPICE and adds/subtracts the waveforms with the proper gain using four op amps on a single chip.