I made an Intv rgb mod

[Unstablewarpfield]

Hey guys!

 

Over these past few weeks I have made myself an rgb mod for my pal Intellivision. My Intv has two color proms in it so I was able to (with help of a diagnostic cart and my scope) determine the input and output bit coding. I made a memory map and wrote the logic in wincupl to two atf16v8cz pld's. I used an adv7125 as video dac.

 

All this to make a pcb that will interface directly on the bottom of the STIC.

 

The prototype gives me excellent image and colors on my framemeister. Pcbs are incoming somewhere next weekend, so hopefully I'll have a working test model soon.

 

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[Intelligentleman]

Awesome! Looks great so far

[+grips03]

Would be neat if sync worked on OSSC.

[+-^CrossBow^-]

17 minutes ago, grips03 said:

Would be neat if sync worked on OSSC.

You know there are at least 2 other solutions that work with OSSC currently available. But I'm also curious if this one will as well. I really like the idea of being able to solder the small PCB directly to the bottom of the STIC for the required signals. They actually come from U10 the color chip, but as that is so small, I can see this working as well. So yeah I'm curious to know more once more information is available. Always good to have options.

[mr_me]

Signals go from the Stic to the colour chip, Pal intellivisions don't have a colour chip.  Most of them do have an Lm1886 chip which actually generates RGB signals.  Since this solution uses Stic output, they should be able to make it work with Ntsc Intellivisions as well.

 

What colour palette are you using?

Edited June 13, 2021 by mr_me

[+grips03]

Well that is good news, I have used 3 other Intv RGB mods, not a single one worked with OSSC. 

 

Confirmed not working with OSSC due to sync issue:
Juice / Fred Kono RGB
Bruce Abbott RGB

Emerson RGB

 

What are the two that do?

[SiLic0ne t0aD]

Crayola the Crayon King's v5 board works with the OSSC. Works with the Retrotink 2x-Scart too. Blows the kono mod out of the water, imho.. Just did my model II a few days ago.

 

He's selling them on eBay.

 

https://www.ebay.com/itm/284134846315

 

I'm not sure about the other one that was mentioned.

Edited June 13, 2021 by SiLic0ne t0aD

[+grips03]

Does anyone know if Crayola RGB works with Intv 1?

[SiLic0ne t0aD]

I'm pretty sure it does from what I read in his thread.

 

I'm about to find out soon.. I'm definitely swapping out the Kono board for the Crayola in my Model I since it seems to be compatible with everything.

[+grips03]

Cool I'll wait to hear back on that if you don't mind posting.

 

Anyone know the name of the other one?

[Unstablewarpfield]

Signals go from the Stic to the colour chip, Pal intellivisions don't have a colour chip.  Most of them do have an Lm1886 chip which actually generates RGB signals.  Since this solution uses Stic output, they should be able to make it work with Ntsc Intellivisions as well.
 
What colour palette are you using?

To be fair the lm1886 does not output an rgb signal. It takes in 3-bit rgb from the color proms though, which is what I reconstructed in smaller form for this mod to fit the way I wanted it to. Output colors are an exact match to the original pal ones. Unfortunately I have no access to an ntsc console. Might purchase one to tinker a bit with.[emoji854]

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[mr_me]

23 minutes ago, Unstablewarpfield said:

To be fair the lm1886 does not output an rgb signal. It takes in 3-bit rgb from the color proms though, which is what I reconstructed in smaller form for this mod to fit the way I wanted it to. Output colors are an exact match to the original pal ones. Unfortunately I have no access to an ntsc console. Might purchase one to tinker a bit with.

Verstuurd vanaf mijn SM-N960F met Tapatalk
 

Thanks.  I was thinking of the UK Intellivisions which have more of a reddish-brown titlescreen.  This looks more like ntsc intellivision colour.

 

Can you post the colour palette you measured and are using?

[Unstablewarpfield]

Prototype soldered in and up an running with no problems on my Framemeister. It's on to testing this now on several different tv's and scalers/line doublers. In the end I'll open source the gerber and jedec files on a website I'm building, so all will be made public. Just want to run it through its paces before I open up the project :-)

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[+grips03]

8 hours ago, Unstablewarpfield said:

Prototype soldered in and up an running with no problems on my Framemeister. It's on to testing this now on several different tv's and scalers/line doublers. In the end I'll open source the gerber and jedec files on a website I'm building, so all will be made public. Just want to run it through its paces before I open up the project ?

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Can you try OSSC?  Would it support NTSC Intellivision?

 

 

[+-^CrossBow^-]

Also curious the results with the Tink devices like the Tink2x SCART (Like I have on hand to test) and the Tink5x of which there are several members here who can test that.

 

[viktorh]

Nice work! I’m very interested. I have a PAL INTV system III that I would like to use with my OSSC, so I’m really hoping this mod is compatible.

[the_crayon_king]

Looks good. I wish I could fit something in a tiny space like that. AFAIK this wouldn't be able to get video on the OSSC without some additional coding for sync. (which maybe you did already?)  

I have my own fix but I do not believe it could fit on a PLD. Yannick worked something out that should be able to work with this on the OSSC. You would have to ask him what it was exactly. 

 

[+-^CrossBow^-]

Yannick's board does work with the OSSC on my setup in at least passthrough, 2x and 5x modes. I think 4x and 3x produce a resolution that my TV isn't okay with and not a fault of the OSSC. Yannick's solution he told me he got from you @the_crayon_king? Basically just isolating some of the input signals with some diodes and a resistor to provide the sync directly. That is the hardware fix I did on the last batch of semi proto boards he sent me and I've been hearing good things. His board is working on the Tink5x in all modes as well minus the 1080p FULL or FILL mode as that causes drop outs. But all others seem to work fine on that device.

 

[the_crayon_king]

3 minutes ago, -^CrossBow^- said:

Yannick's board does work with the OSSC on my setup in at least passthrough, 2x and 5x modes. I think 4x and 3x produce a resolution that my TV isn't okay with and not a fault of the OSSC. Yannick's solution he told me he got from you @the_crayon_king? Basically just isolating some of the input signals with some diodes and a resistor to provide the sync directly. That is the hardware fix I did on the last batch of semi proto boards he sent me and I've been hearing good things. His board is working on the Tink5x in all modes as well minus the 1080p FULL or FILL mode as that causes drop outs. But all others seem to work fine on that device.

 

Yes I know Yannick's works on the OSSC. I pointed him to a solution (that would work on his board) but he worked out his own thing himself. His fix and my fix are not at all the same.

I was pointing OP to the fact that Yannick's fix (whatever it is) should work here. 
The data capture on my Intellivision RGB thread is enough to work out the logic needed.

 

If Yannick's board works on the 5X (when mine doesn't) then I am sure I can make a fix that works across the board.

I just need to get a hold of a 5X for like a weekend and I am sure I can make it work.

 

@Unstablewarpfield If you are only using 4 bits input to the ADV then your output will be limited to 672mv p-p [this will make white possibly off-colored]. 

You can adjust RSET to fix this (but it will increase the relative brightness of the other colors). Or you can tie the unused bits to some of the used bits.

I think you might be better off using a PLD > buffer > resistors > THS7374. That is if you are trying to make a board for DIYers and not use more than 4 bits input.

That is my 2cents; feel free to ignore any of that. 

[YannAros]

The simple solution I've implemented was drafted based on the measurements and observation from @the_crayon_king but I've simplified it a lot based on the previous observations and tests I did.

It simply implements SYNC as being NOT((V1 OR V4) AND V5) instead of NOT(V1 AND V5). The fix with additional diodes is performing (V1 OR V4) so that we can re-use previously produced boards.

The final fix is implementing the full equation within one 4xNAND chip.

Here is a link to the EasyEDA project : https://easyeda.com/yannick.erb/Intellivision-Secam-RH-RGB-Mod_copy_copy

This is the French version of the board that is bigger in order to fit at the location planned for the power supply board that is not present in some french versions of the Intellivision.

Edited June 21, 2021 by YannAros

[Unstablewarpfield]

We're about a year on now and I decided to take this design a bit further a couple of weeks ago. I used an ICE40 HXK8 board to inject missing equalization and serration pulses and store colors. For now I still have glitches in my sync signal. I found the position of Vsync to be in a weird spot if I wanted to stick to PAL standards so I also had to move that a bit which created said glitches. We'll see how disruptive they are. The sync signal on the image attached gives me a nice image on my Framemeister. That said... Framemeister takes about anything I throw at it so I am waiting on an OSSC to test what that will do. Goal is to get this on thesame footprint als the mod posted above here. Eventually I'll also purchase an NTSC model to make this compatible. Still very much a work in progress ?

 

Sync taken before attenuation. 

 

 

 

Edited May 21, 2022 by Unstablewarpfield

[the_crayon_king]

6 hours ago, Unstablewarpfield said:

We're about a year on now and I decided to take this design a bit further a couple of weeks ago. I used an  board to inject missing equalization and serration pulses and store colors. For now I still have glitches in my sync signal. I found the position of Vsync to be in a weird spot if I wanted to stick to PAL standards so I also had to move that a bit which created said glitches. We'll see how disruptive they are. The sync signal on the image attached gives me a nice image on my Framemeister. That said... Framemeister takes about anything I throw at it so I am waiting on an OSSC to test what that will do. Goal is to get this on thesame footprint als the mod posted above here. Eventually I'll also purchase an NTSC model to make this compatible. Still very much a work in progress ?

 

Sync taken before attenuation. 

 

 

 

Of what I tried of restoring narrow equalization pulses or inverted hsync pulses it would make it work on one video scaler but stop working on another. (because it wasn't 100% correct).

However, all scalers seem to work with just having no sync data at times:

You could get 100% correct sync. I just don't think it will be worth the effort.  

Vsync is turned on by "11001" in my files and I did not retime it. 

[Unstablewarpfield]

Of what I tried of restoring narrow equalization pulses or inverted hsync pulses it would make it work on one video scaler but stop working on another. (because it wasn't 100% correct).
However, all scalers seem to work with just having no sync data at times:

You could get 100% correct sync. I just don't think it will be worth the effort.  
Vsync is turned on by "11001" in my files and I did not retime it. 

I was thinking about just leaving vsync in its place, and have serration pulses "where ever" they would end up following hsync but when I found about equlization timings for PAL video it did not make any sense according to what I was seeing on my scope.
Equalization and serration intervals before, during and after Vsync on the Intellivision is not 160ms as it appearently should be. So yeah... it was either leave Vsync be and inject hsync pulses, or try a bit more effort and get timings dialed in.

I did not make narrow pulses, but that could be done rather easy if needed. Just curious to see how the ossc will handle this.

In the end it's all hobby and about learning things :-)

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[Unstablewarpfield]

Alright... received the ossc. Did nothing but simply plug stuff in with this result. I have to get familiar with this scaler first but I assume this result is good. Never mind compression and artifacts caused by my phone.

 

 

 

 

[+-^CrossBow^-]

Excellent!