48 replies to this topic

[5-11under]

Hi there,

I'm wondering if any of you have an Intellivision that has been modified to output composite video (or otherwise)? I'm wondering how good or bad the output looks. What/whose mod is it? How does it compare to the RF output? How does it compare to other composite outputs for other consoles (which console, and, if applicable, which mod)? Any detail would be appreciated. Pictures are even better.

I don't own an Intellivision anymore, but I'm thinking of getting one, and creating a high quality mod for this console. However, if the current composite output mod is good enough, I'll move on.

Thanks,
5-11under

[jaybird3rd]

I can't take pictures right now, but I have an Intellivision II with a composite mod from 8BitDomain.  Except for a slight ghosting problem, it looks very good.

Before I bought the 8BitDomain mod, I tried building two others for myself based on the various schematics available on the Internet.  Those worked, too, but I wasn't entirely happy with them because they both had a problem with vertical bands in the video; perhaps I did something wrong when I built them.  The RF video was already very clear and did not have this problem, so I was hesitant to make the switch until I found something substantially better.

[Ransom]

I had the mod from 8bitdomain...the one resold completed with console through Atari2600.com.  The ghosting problem was very distracting in some games -- such as AD&D Cloudy Mountain -- but not as much in games with a dark background, like Astrosmash.  But it was not acceptable to me, so I returned the console to Atari2600.com (who cheerfully refunded the cost, and now I believe have a note on their site about the problem which according to them and their tech is insurmountable with the INTV).

So now I use a very well shielded RF cable, and the result is 99% as good as composite.

[jeremysart]

I do know this, modern flat panel LCD tv's have very very low RF interference.
I have my INTV hooked up to my 32 inch Element, which is 780i, and the games look crisp and beautiful!

Also, I use an RF switch with the coaxial adapter, and I cut off the two prongs that are used to screw into older antenna only TV's because they cause some interference, and I have noticed when they are cut off, games look better on any tv.

[Atariboy]

jeremysart, on Tue Dec 1, 2009 1:19 PM, said:

Also, I use an RF switch with the coaxial adapter, and I cut off the two prongs that are used to screw into older antenna only TV's because they cause some interference, and I have noticed when they are cut off, games look better on any tv.

I bet if you use one of these, you'll get even better peformance than from that tv/game switchbox.

https://www.atari260...NTHAR0005A.html

[Hatta]

Has anyone tried this one: http://intelliwiki.k...eo_Modification

The RF out port on my INTVII broke, so I'm needing to get it modded.  I much prefer to build my mods myself, so I'm planning on doing that one.  That looks simple enough, I would like to hear how good the results are though.

[jaybird3rd]

Hatta, on Tue Dec 1, 2009 2:27 PM, said:

Has anyone tried this one: http://intelliwiki.k...eo_Modification

The RF out port on my INTVII broke, so I'm needing to get it modded.  I much prefer to build my mods myself, so I'm planning on doing that one.  That looks simple enough, I would like to hear how good the results are though.

Yup, that's one of the ones I built.  Again, maybe I did something wrong, but when I tried this circuit in my Intellivision II, the colors were a bit washed out and there were noticeable vertical bands in the video output (this was on a conventional 13" CRT television, not a flat-panel).

[5-11under]

It sounds like most of you are fairly pleased with what you've got. If possible, I'd really like to see some pictures of your TV running the Intellivision, whether it's RF or composite.

No rush, except I'm really curious.

Thanks,
5-11under

[GrizzLee]

5-11under, on Wed Dec 2, 2009 7:37 AM, said:

It sounds like most of you are fairly pleased with what you've got. If possible, I'd really like to see some pictures of your TV running the Intellivision, whether it's RF or composite.

No rush, except I'm really curious.

Thanks,
5-11under

I am happy with the one I purchased off of Beeslife. I use my Intelly 2 on a Toshiba 14" FST tube TV. Looks GREAT!! No pics to post. Maybe tonight.

http://www.beeslife....d/video_mod.php


-Lee

[HARMIK]

Please please make a good mod for the Intellivision I have the 8bit one installed buy mike from 8bit, and yes it is better than RF but the ghosting is very distracting in some games as Ransom said. I have asked different people about this over time. Some time ago I asked Joe Zbiciak and got this  response.

" On the S-video output:  The Intellivision doesn't generate separate chroma and luma signals internally, so S-video output would be rather tricky.  The Intellivision's STIC actually outputs a 5-bit "pixel color" directly, and a separate chip, the AY-3-8915 Color Processor modulates that into a 4-bit "digital NTSC" output.  This 4-bit output goes through a resistor ladder to generate the final NTSC output.  To implement S-video, one would have to actually make the equivalent of TWO composite mods, and replace the AY-3-8915 with two new pixel decoders.

Seeing as we haven't even successfully characterized the outputs on the AY-3-8915, determining that transfer function is problematic at best.  And since I don't have any hardware capable of S-video anywhere near my Intellivision, I'm highly unlikely to implement this myself.

OTOH, I have toyed with the idea of implementing a VGA scan doubler.  This would convert the Intellivision's raw digital pixels into a VGA output using a dedicated processor and a proper VGA driver.  Many modern digital TVs have a VGA input, so that would actually give the absolute highest quality.  If the processor was fast enough, it could even implement various effects, such as the "Scale2x" algorithm.  I haven't touched the idea though, because I'm too busy though."

I really would love better video output from my Intellivision even high quality composite would be a lot better than what we have now, I only just found this thread because I emailed David from Beeslife and happened to mention it again and he pointed me to this.

And did I say PLEASE

[5-11under]

HARMIK, on Fri Jan 1, 2010 2:53 AM, said:

Seeing as we haven't even successfully characterized the outputs on the AY-3-8915, determining that transfer function is problematic at best.  And since I don't have any hardware capable of S-video anywhere near my Intellivision, I'm highly unlikely to implement this myself.

OTOH, I have toyed with the idea of implementing a VGA scan doubler. This would convert the Intellivision's raw digital pixels into a VGA output using a dedicated processor and a proper VGA driver. Many modern digital TVs have a VGA input, so that would actually give the absolute highest quality. If the processor was fast enough, it could even implement various effects, such as the "Scale2x" algorithm. I haven't touched the idea though, because I'm too busy though."

I was thinking of replacing the AY-3-8915 with alternate circuitry, to provide component, and possibly S-video and composite. According the the datasheet, the "transfer function" of the AY-3-8915 isn't that complicated. Do you have any details or links with AY-3-8915 information (besides the two page datasheet)?

The beautiful thing about the Intellivision is that the digital video signals are readily accessible, so digital solutions such as DVI are also conceivable (as opposed to the A2600 and CV, where the digital signals are locked inside fairly complicated video ICs - to get DVI out of an A2600 or CV would require either replacing the complicated video IC or converting the analog signals to digital).

Thanks,
5-11under

[HARMIK]

I have sent Joe an email maybe he can help, but please do not give up on this. The Intellivision is an awesome system I can't tell you how much I would love it to have better video output.

[intvnut]

5-11under, on Fri Jan 1, 2010 7:19 PM, said:

HARMIK, on Fri Jan 1, 2010 2:53 AM, said:

Seeing as we haven't even successfully characterized the outputs on the AY-3-8915, determining that transfer function is problematic at best.  And since I don't have any hardware capable of S-video anywhere near my Intellivision, I'm highly unlikely to implement this myself.

OTOH, I have toyed with the idea of implementing a VGA scan doubler. This would convert the Intellivision's raw digital pixels into a VGA output using a dedicated processor and a proper VGA driver. Many modern digital TVs have a VGA input, so that would actually give the absolute highest quality. If the processor was fast enough, it could even implement various effects, such as the "Scale2x" algorithm. I haven't touched the idea though, because I'm too busy though."

I was thinking of replacing the AY-3-8915 with alternate circuitry, to provide component, and possibly S-video and composite. According the the datasheet, the "transfer function" of the AY-3-8915 isn't that complicated. Do you have any details or links with AY-3-8915 information (besides the two page datasheet)?

The beautiful thing about the Intellivision is that the digital video signals are readily accessible, so digital solutions such as DVI are also conceivable (as opposed to the A2600 and CV, where the digital signals are locked inside fairly complicated video ICs - to get DVI out of an A2600 or CV would require either replacing the complicated video IC or converting the analog signals to digital).

Thanks,
5-11under

What I meant about the "transfer function" being a bit weird is that there seems to be some non-linear transistor effects that shift the values around from what the data sheet describes.  I've tried converting the values in the data sheet into RGB with all manner of YIQ transformations, and failed dramatically.  For one, brown actually came out brown, not olive-drab, and blue wasn't as saturated as it is on a real Intellivision.

Now, if you just want to make up your own "close enough" color palette, then it's pretty simple to make a decoder for the pixel codes and just do whatever you like for S-video or DVI.  My "transfer function" comment mainly applies to getting the exact Intellivision colors.  If you are OK with, say, grabbing the palette from one of the emulators out there, then there's nothing more to do.  Build a couple D/As for S-video output or three for RGB output.

If I ever get time, I still want to do that Intellivision-to-VGA scan doubler.  Some day, in my copious free time.

[tz101]

Lee Krueger, on Wed Dec 2, 2009 10:03 AM, said:

5-11under, on Wed Dec 2, 2009 7:37 AM, said:

It sounds like most of you are fairly pleased with what you've got. If possible, I'd really like to see some pictures of your TV running the Intellivision, whether it's RF or composite.

No rush, except I'm really curious.

Thanks,
5-11under

I am happy with the one I purchased off of Beeslife. I use my Intelly 2 on a Toshiba 14" FST tube TV. Looks GREAT!! No pics to post. Maybe tonight.

http://www.beeslife....d/video_mod.php


-Lee

This looks fairly straightforward to do, but the only problem is I would prefer stereo sound output. This mod only outputs mono sound.

[jaybird3rd]

tz101, on Sat Jan 2, 2010 9:53 AM, said:

This looks fairly straightforward to do, but the only problem is I would prefer stereo sound output. This mod only outputs mono sound.

Why not just get an RCA Y-cable and split the audio to both channels?

[tz101]

jaybird3rd, on Sat Jan 2, 2010 11:53 AM, said:

tz101, on Sat Jan 2, 2010 9:53 AM, said:

This looks fairly straightforward to do, but the only problem is I would prefer stereo sound output. This mod only outputs mono sound.

Why not just get an RCA Y-cable and split the audio to both channels?

Doesn't function the same. All that gives is identical sound to both channels. I did a stereo mod to my NES a while back and ended up with distinctly different sound to the left ad right speakers. That is why an RCA Y cable will not suffice.

[5-11under]

tz101, on Sat Jan 2, 2010 12:14 PM, said:

jaybird3rd, on Sat Jan 2, 2010 11:53 AM, said:

tz101, on Sat Jan 2, 2010 9:53 AM, said:

This looks fairly straightforward to do, but the only problem is I would prefer stereo sound output. This mod only outputs mono sound.

Why not just get an RCA Y-cable and split the audio to both channels?

Doesn't function the same. All that gives is identical sound to both channels. I did a stereo mod to my NES a while back and ended up with distinctly different sound to the left ad right speakers. That is why an RCA Y cable will not suffice.

From the schematic, it looks like there are 3 sound sources from one chip, all connected to each other. However, I don't think the games are programmed taking into account the different channels, so it's not like you'll be able to hear things on the right of the screen in the right speaker, etc. The stereo you would hear would me meaningless, I think?

Thanks,
5-11under

[HARMIK]

Hmmm interesting about the colour I have a number of NTSC Intellivisions and they all seem to give slightly diferant colours. I have changed over all my retro systems from Pal to NTST once I soure the  difference in speed to the game and sound, and the horrible bourders of Pal systems. However one thing I did notice about the Pal Intellivision is I thought the colours were better and I put that down to Pal supposing to have better colour than NTSC.

And I remember when I was a kid and over in the U.S. thinking it was funny that I could turn a nob on the TV and turn the grass blue you see in Australia we never had to or had a hue adjustment. But back to my point all my Pal systems output the same colour from system to system and as an example in Armor Battle the buildings are a dark brown, all the games seem to have better colours and when I have compared them side by side it seems as if thats the way it was supposed to look at least to me.

And yes in Armor Battle my NTSC systems the buildings come out olive-drab I spent ages trying to make them brown playing with some adjustment in the Inellivision and the hue on my TV.

[HARMIK]

Is there any progress on this.

[5-11under]

HARMIK, on Sun Jan 17, 2010 1:04 AM, said:

Is there any progress on this.

Not yet. I'm hoping to get an Intellivision in the spring, and then do some work on this. In the meantime, I'd still love to see some TV screen shots of anyone's RF or composite output.

Thanks,
5-11under

[HARMIK]

Ok this is what I get with my 8bitdomain composite mod, Its defiantly better than RF but I get this horrible ghosting.

Attached Thumbnails

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[Ransom]

That's exactly how mine looked as well.

I'll post pics of my unmodded Intelly's output when I get a chance.  I'm really quite pleased with the RF out on that machine.

[Ransom]

Here's what I get with RF out (note that the moire patter captured by the camera isn't visible with the naked eye):

Here's the full screen:


Here's some detail:


And some more detail:


Note the faint shadow around objects.  The 8bitdomain mod made these much more evident, which is why I nixed it.  RF out, using a high quality, very well shielded cable (a composite video cable, actually) works very well for me.  Not that I wouldn't love to have S-Video (or even composite) some day, but it would seem that whoever designs that mod will have to basically redo the entire video circuit in order to get rid of the shadow.

[5-11under]

Hi all,

The good news is that I should have an Intellivision or two in my possession on Saturday (thanks to coleconut). I've got some other things to do before diving in, but I'm looking forward to doing some testing. This may take some time, but I'm hopeful for some good results. I'll keep you posted.

Thanks,
5-11under

[HARMIK]

Very exited about this I am glad you have not given up on it.