RGB/YPbPr Intellivision Thoughts

[the_crayon_king]

1 hour ago, -^CrossBow^- said:

Awesome! I've already got one of your older boards that was sent to me to be installed into a model 2. I've done so strictly in YUV output for this client and advised them that in the future, if they wish, it could be sent back to me and have the newer version board installed in place of the older and then separate RGB with a toggle switch added at that time. But they are in a hurry, so I'm going to be shipping out this component output only intelly2 likely tomorrow.

 

 

I would have waited to sell these if I knew restoring sync was possible with the components I have. I had said that it should be possible and this and that but mostly that was just being hopeful.

 

Since I changed the bits I was using for sync, testing will have to be done fresh. I have 80 games and many scalers so I will be able to confirm those. Thunder Castle has been confirmed on the OSSC up to stage 3 for example. 

 

Anyway, the new boards will be the same pin order as the old ones so switching them out should take very little effort. If everything goes as planed this will be my last revision of an analog board for these consoles.

 

After validation I will be moving over to the O2 and then to those other consoles. The code for those has been written for years so mostly I will just be seeing if anything needs tweaked.

 

[+-^CrossBow^-]

So if I'm reading a post on FB correctly, it appears that Fred's older RGB for the Intellivision actually works with the new Tink5x without issues? That is good news and I would suspect that Crayon's older board and obviously upcoming newly designed board, would as well. I thought about getting a tink5x but I really don't have a pressing need for one with my current setup using the OSSC.

 

Anyway, just thought @the_crayon_king would be interested to know this.

 

I also released a video this morning installing one of your boards into another Intellivision 2 console. This was one of your older boards sold on ebay so I wired it up for component YUV output only as I wanted to provide the best compatibility I could for the client that owns this particular Intellivision 2.

 

 

[the_crayon_king]

1 hour ago, -^CrossBow^- said:

So if I'm reading a post on FB correctly, it appears that Fred's older RGB for the Intellivision actually works with the new Tink5x without issues? That is good news and I would suspect that Crayon's older board and obviously upcoming newly designed board, would as well. I thought about getting a tink5x but I really don't have a pressing need for one with my current setup using the OSSC.

 

Anyway, just thought @the_crayon_king would be interested to know this.

 

I also released a video this morning installing one of your boards into another Intellivision 2 console. This was one of your older boards sold on ebay so I wired it up for component YUV output only as I wanted to provide the best compatibility I could for the client that owns this particular Intellivision 2.

 

 

 

Just finished the video. It's great and a lot better than anything I can put together. The install methods are better than what I have been doing I might have to borrow some of that. I am now curious how you tackle RGB installs on the model 2 since that is currently a thorn in my side.

 

One note though. As I have recently learned I wouldn't recommend removing those 75 ohm resistors for any reason. Whatever you have to do in order not to remove those resistors is my recommended action. 

 

If you have series resistors in your cable you won't get the correct voltages but it shouldn't be harmful.

I understand the desire to use the same cable for everything but I don't know how to incorporate the Sega cables without adding the THS7374., which while cheap would bloat the board.

 

Eventually I will get around to testing the difference between having the series in the SCART cable vs inside the console on a Genesis or something. I am curious if there is a difference that can be captured on the scope. I bypass the RGB on my Sega consoles and then use my own series on the output.

 

I am curious if Fred's board through the 5X or my old boards have the sync dropped on Thunder Castle. Which seems to be the best test for sync drop that I can manage sans LTO.

 

Anyway, I have the newer boards in. Initial testing has been looking good and I was able to get OSSC video with no issue. That is I was able to get video with the wrong buffer. What makes the buffer "wrong" is that it shouldn't be sent signals higher than VCC (I made it 3.3V). So the 5-6V the Intellivision puts out shouldn't be used with the way I configured it. It doesn't seem to be hurting anything (yet) but I do not plan to put these out there. I have the new buffer and I am going to bodge it in and experiment from there.

Edited May 4, 2021 by the_crayon_king

[+-^CrossBow^-]

44 minutes ago, the_crayon_king said:

 

Just finished the video. It's great and a lot better than anything I can put together. The install methods are better than what I have been doing I might have to borrow some of that. I am now curious how you tackle RGB installs on the model 2 since that is currently a thorn in my side.

 

One note though. As I have recently learned I wouldn't recommend removing those 75 ohm resistors for any reason. Whatever you have to do in order not to remove those resistors is my recommended action. 

 

If you have series resistors in your cable you won't get the correct voltages but it shouldn't be harmful.

I understand the desire to use the same cable for everything but I don't know how to incorporate the Sega cables without adding the THS7374., which while cheap would bloat the board.

Thanks for the kind words! I mainly put it together because this would be the 3rd time I've installed your board into a system and as I knew the install process would be the same for this board and your newer ones I figured it would be a good valid tutorial of sorts for others.

 

I actually advised to LEAVE those in at first and only try removing them if you need to. In my case using a set of the Insurrection Industries Gen 2 RGB SCART cables the picture wasn't that much different in brightness as those RGB installs that don't have them in place.

 

On the RGB install, I've only done mine in this manner. On my intellivision 2, what I did was to remove the RF modulator completely. I then used a 9-pin Genesis/MD 2 AV port. Soldered it upside down on the large exposed ground plane where the RF output was. I then fed my wires from the RGB board to the AV out through one of the holes that the RF modulator used for the anchors. I still mounted your board on the bottom of the PCB but places it near where the RF modulator was so that the wiring could be made as short as possible to avoid any additional interference. If you look at the pics I posted on my Intelly 2 RGB install in this thread, you will see that I added the 10µf cap directly off my small breakout board I have on the 9-pin din and then ran the wire from that cap back to the same spot near the RF modulator where the original audio input wire was. 

 

The main difference I think between what you were doing and what I'm doing is that I try and keep everything on the mainboard as much as possible and only have the new AV jacks be separate. Using connectors as I do in the wiring allows for the mainboard and mod to all come out together without having to desolder any wiring in the process. This is how I try and do all of my service work on consoles.

 

Soon as that new version is ready, you let me know! Should be a trivial matter to swap out the one I have in my Intelly 2 with the new version once ready.

 

[Reality Studio]

I just got a Retro Tink 5x in case you need a a hand testing, I currently have an Intellivision 2 with a crappy composite mod. 

[the_crayon_king]

@-^CrossBow^- I have some things to take care of but I should be done with the (hopefully) final design in a day or so. Swapping them out will be easy enough. I am using through holes instead of pads this time. I prefer using through holes (and I need them for quick testing) but people should be cautious not to short wires through the bottom down to the Intellivision motherboard. I removed the solder jumpers and instead just left through hole jumpers (since they both do the same thing). I may add the solder jumpers back if space allows. I will let you know as soon as I have something of a date for these.

 

@Reality Studio I was planning on just selling a small batch and seeing what happens. If it doesn't work it would have to be returned (or broken) for a refund. I will be testing on pretty much everything except for the 5X but I assume if it works on the 2x then the 5x should not be a problem.

-----------------------------------------------------------------------------------------------------------------------------

Anyway I have nothing new to report on testing. I have made minor changes here and there but that is about it.

 

I did fix one of the broken model 1's I had laying around. The issue was those two transistors (which seems to be a common problem).

 

The 12 ohm resistor tested good but since it was discolored I replaced it:

https://i.imgur.com/esthgTW.jpg

 

The bottom side of the transistor through holes looked scorched:

https://i.imgur.com/bGVgx63.jpg

 

The top side looks even more scorched (this is the new transistors installed):

https://i.imgur.com/QFfE1IC.jpg

 

I used 2N3906 transistors and a 12.0 OHM 3W resistor

 

This might possibly be something people should do as a bit of preventive maintenance.

Edited May 5, 2021 by the_crayon_king

[+-^CrossBow^-]

1 hour ago, the_crayon_king said:

@-^CrossBow^- I have some things to take care of but I should be done with the (hopefully) final design in a day or so. Swapping them out will be easy enough. I am using through holes instead of pads this time. I prefer using through holes (and I need them for quick testing) but people should be cautious not to short wires through the bottom down to the Intellivision motherboard. I removed the solder jumpers and instead just left through hole jumpers (since they both do the same thing). I may add the solder jumpers back if space allows. I will let you know as soon as I have something of a date for these.

 

I did fix one of the broken model 1's I had laying around. The issue was those two transistors (which seems to be a common problem).

 

The 12 ohm resistor tested good but since it was discolored I replaced it:

https://i.imgur.com/esthgTW.jpg

 

The bottom side of the transistor through holes looked scorched:

https://i.imgur.com/bGVgx63.jpg

 

The top side looks even more scorched (this is the new transistors installed):

https://i.imgur.com/QFfE1IC.jpg

 

I used 2N3906 transistors and a 12.0 OHM 3W resistor

 

This might possibly be something people should do as a bit of preventive maintenance.

Awesome news and yes I agree with the through holes. I trim that stuff in most cases like with the UAV for example. But that also means I have to attach the wires to the board before installing the board. 

 

And yes those 3906s are known to burn out over time. I actually do replace them out on Intelly model 1s that are sent to me for service. Even if it is working, I will replace them out anyway for good measure. I actually use 2907s instead of the original 3906s as I have a bunch of those on hand and I think they are rated slightly higher in spec. They don't seem to get quite as hot but that could just be me.

 

[YannAros]

Hi

 

I have no experience with the Pi but looking at this : https://github.com/c0pperdragon/Amiga-Digital-Video

 

It looks very feasible to adapt it so that it takes V1-V5 as input and generates directly an Hdmi output.

That would solve all issues with sync signal and additional converters.

 

 

[the_crayon_king]

17 hours ago, YannAros said:

Hi

 

I have no experience with the Pi but looking at this : https://github.com/c0pperdragon/Amiga-Digital-Video

 

It looks very feasible to adapt it so that it takes V1-V5 as input and generates directly an Hdmi output.

That would solve all issues with sync signal and additional converters.

 

 

Yes something like that could be used to put out HDMI. I will have to look more into it. I don't think that device alone could fix sync without recreating it (like I have done). The HDMI section may tolerate missing sync pulses for all I know, or may have a PLL. There are other limitations with the PI like 4:4:4 RGB (instead of 8:8:8).

 

If I could find a product that auto centers 8:8:8 RGB and scales it to 4X or 5X then that would at least cover all the 240 systems. Really that should already be out there someplace.

 

TLDR HDMI is something I am looking into but I have to get analog RGB validated first (since that is the first step in getting HDMI). Natively putting out RGB from a console probably won't look any better than the 5X or the OSSC.

[YannAros]

I believe that for the Intellivision you do not need to go through rgb first, you can translate V1-V4 to any 24bit color you want and make it fully configurable for each color.

 

The sync signal is also encoded in V1 and V5, with the Pi we don’t care about respecting the normes. Hdmi output is totally generated from the Pi, so sync signal inside is going to be normalized.

[the_crayon_king]

On 5/8/2021 at 2:36 AM, YannAros said:

I believe that for the Intellivision you do not need to go through rgb first, you can translate V1-V4 to any 24bit color you want and make it fully configurable for each color.

 

The sync signal is also encoded in V1 and V5, with the Pi we don’t care about respecting the normes. Hdmi output is totally generated from the Pi, so sync signal inside is going to be normalized.

I know going through a FPGA and a HDMI transcoder would be less delay than going through the PI. For 10$ or so it would deff be worth looking into,. even considering the delay.

 

I am assuming the PI I/Os are not 5V tolerant so there would at least need to be a logic level translator (level shifter). I don't even know what language that thing is written in but if it resolves the centering/scaling then the rest would be pretty easy.

 

I still plan to keep going for my own FPGA based HDMI solution. Getting RGB into 8 bit outputs is like the first step so I have that already.

[+fdr4prez]

8 hours ago, the_crayon_king said:

I know going through a FPGA and a HDMI transcoder would be less delay than going through the PI. For 10$ or so it would deff be worth looking into,. even considering the delay.

 

I am assuming the PI I/Os are not 5V tolerant so there would at least need to be a logic level translator (level shifter). I don't even know what language that thing is written in but if it resolves the centering/scaling then the rest would be pretty easy.

 

I still plan to keep going for my own FPGA based HDMI solution. Getting RGB into 8 bit outputs is like the first step so I have that already.

Correct, the Pi's gpio are not 5v tolerant.

 

The Pi Zero v1.3 doesn't have wifi or bluetooth, but only costs $5

Or go for the Pi Zero W for $10

 

It is really convenient if you live near a Micro Center, otherwise order from Adafruit  - unless you aren't in the US

[the_crayon_king]

So far I am just testing current setting resistors out from the buffer (using 110 atm). I did note that certain resistances improved the shape of the signals.  Refer to this: https://i.imgur.com/TF5suM9.png. (Yellow is input purple is output from the buffer) [I tried both loaded and unloaded yellow looks the same]

 

Since the inputs to the CPLD and DAC are all TTL this probably doesn't make a difference but it is worth mentioning.

The point of the logic level translator is to deal with the higher voltage seen on the model 1's (6ish volts).

I have a resistor value for the model 1 that works. I just need to confirm if it is the same on the model 2 and then I can order these. I may make use of the older boards (with the new CPLD) on the model 2's I have and put those up for sale or something. I am thinking at this rate the parts I need will be here before the next batch of boards.

 

Another thing I noticed is that installing the kit (at least the newer version). Seems to effect RF. If the mod kit can make RF worse then it stands to reason that RF can make the kit video worse. This is something I will look into. Although from what I have seen over the OSSC everything looks great.

 

I will look deeper into HDMI as soon as the RGB/YPbPr kits are confirmed as working. I don't know if the PI is the best thing to use. It would deff be the most cost effective.

[Icelvlan]

Looking forward to new board. How many components have changed?

[+-^CrossBow^-]

1 hour ago, the_crayon_king said:

Another thing I noticed is that installing the kit (at least the newer version). Seems to effect RF. If the mod kit can make RF worse then it stands to reason that RF can make the kit video worse. This is something I will look into. Although from what I have seen over the OSSC everything looks great.

Well, RF seemed to be the same with your older version board in the Intelly 2 that I installed for a client. On my Intelly 2 I removed the RF and mounted my RGB output there instead. But I have discovered that if you also want composite (CVBS), you have to leave the RF modulator in place. No idea why but it seems to be similar to the CV in that composite results in a blank or scrambled looking picture unless the RF modulator is installed. So, I would advise that if you already have composite as I did in my model 1 and still want to use it. (I did because the jacks are already installed), then RF must remain in place. 

 

BTW @the_crayon_king I sent you a reply to the latest PM chain we have going. Seems you have been talking to @YannAros and now I need you to share your OSSC settings for intellivision use when you get a chance.

 

[the_crayon_king]

1 hour ago, -^CrossBow^- said:

Well, RF seemed to be the same with your older version board in the Intelly 2 that I installed for a client. On my Intelly 2 I removed the RF and mounted my RGB output there instead. But I have discovered that if you also want composite (CVBS), you have to leave the RF modulator in place. No idea why but it seems to be similar to the CV in that composite results in a blank or scrambled looking picture unless the RF modulator is installed. So, I would advise that if you already have composite as I did in my model 1 and still want to use it. (I did because the jacks are already installed), then RF must remain in place. 

 

BTW @the_crayon_king I sent you a reply to the latest PM chain we have going. Seems you have been talking to @YannAros and now I need you to share your OSSC settings for intellivision use when you get a chance.

 

Just mix composite from the RGB of the kit. It should be about a million times cleaner. I think further back there was a picture comparison of the waveform. RF has a pullup or something on it. It also has probably the worst looking "composite" signal that I have ever seen. Just use a BH7236AF circuit and you can get RGB, Composite, and S-Video. The pulldowns on the BH would not be 75 I haven't done the math just yet but it would be higher than 75. Whatever is needed to make a 0.7p-p signal into 1v p-p. I forgot all about composite I will go back and look at that.

I will make a board that sits below the next batch of boards and puts out all of those things. The only caveat is that the thing shouldn't be used with YPbPr mode. I can mix YPbPr from the RGB outputs of the BH encoder so it would be possible to put out like everything all at once. Using the BH would also mean the RGB outputs would be the normal 75 ohm series resistor so by knocking that off you would be able to use the SEGA cable you guys keep trying to use.

 

My OSSC settings for my kit are default. The fix I pointed him towards was more like a band-aid. He may have done a completely different solution for all I know. What we were discussing from what I recall was something that would stretch out the width of hsync. To about 11us ? So changing your hsync width setting in the OSSC to about 11us may help. Sync is supposed to be about 4.6us so yea that is why I didn't go that route. To be clear the method he is using is completely unrelated to the fix I am doing. So issues on one would not necessarily be relevant to the other.

 

--edit the pulldown needed for the BH encoder would be between 160 and 200. I can't give a more exact number without testing it. If the thing relied on math alone then 190 would probably be correct.

 

Edited May 11, 2021 by the_crayon_king

[the_crayon_king]

Parts have arrived. PCBs will be here on the 24th (estimated). I have the items to do a YPbPr configuration as well (refer to Crossbows images). I have enough parts now to test the final configuration and code for the boards that will be coming in. If all goes well those boards will be the final product. If testing goes well I will put up around 25 for sale same or next day. I will need about 10 for my personal consoles/uses. I will have 50 boards on hand so 40 for distribution and I'll have enough parts to populate something like 110 boards.

 

I will test both boards against each other (with the new CPLD/code); so the new board (rev 5) against the old one (rev 3) and if one has attributes better than the other that is what I will use. The major difference between the two boards is the logic level translator,. which should be used only because the Intellivision model 1 puts out 6V on its logic outputs. [I have done a burn in test for several days on a model 1 with the old rev 3 design and didn't have any issues.]

 

 

There is also the possibility of using a different encoder to get Y/C and CV out as well. I built out an addon board that can do the same thing but this other encoder can do RGB, Y/C and CV just from digital inputs so it would fit in about the same space as the current boards just with the addition of Y/C and CV. The alternative is the encoder I was talking about earlier but it would need sandwiched together. I will probably test both at some point.

 

If anyone has relevant questions or input now would be the time to bring it up as I want to be done with major changes and move on to the other consoles I have been preparing for.

[Reality Studio]

I'll definitely buy one! One question that may have been already answered in an earlier post, but does this work on both Intellivision 1 and 2?

[the_crayon_king]

8 minutes ago, Reality Studio said:

I'll definitely buy one! One question that may have been already answered in an earlier post, but does this work on both Intellivision 1 and 2?

All revisions work on the model 1 and 2. The biggest thing is the the OSSC should now be compatible and this should take care of sync drops on certain games. I'll have to test everything again to confirm there isn't any new issues from the change in sync logic but it looked pretty good last time I looked into it.

I will test over my generic scaler, XRGB, OSSC, retrotink 2X, CRTs, and the datapath capture card.

Mostly, I will concentrate on the CRTs and OSSC. That will leave HD retrovision, Retrotink 5X, etc up to you guys to test out.

[Icelvlan]

Cool will this be compatible with Odyssey 2?

[Reality Studio]

5 hours ago, the_crayon_king said:

All revisions work on the model 1 and 2. The biggest thing is the the OSSC should now be compatible and this should take care of sync drops on certain games. I'll have to test everything again to confirm there isn't any new issues from the change in sync logic but it looked pretty good last time I looked into it.

I will test over my generic scaler, XRGB, OSSC, retrotink 2X, CRTs, and the datapath capture card.

Mostly, I will concentrate on the CRTs and OSSC. That will leave HD retrovision, Retrotink 5X, etc up to you guys to test out.

 

Cool, I'll be testing it out on the Retrotink 5x.

[+-^CrossBow^-]

20 hours ago, the_crayon_king said:

. That will leave HD retrovision, Retrotink 5X, etc up to you guys to test out.

I won't have access to the Tink5x anytime soon, but we already determined that the HDR cables aren't likely to work given the fact they require a composite sync signal and not the usual c-sync. As  result, you have to have a composite mod added to the mix and even then, the composite signal is still wonky and not likely t work. HDR cables didn't work to convert the old RGB when I tested it. 

 

But I'm for sure in on getting at least two of them. One for my current Intelly 2 I have a V3 board in that is wired up for both YUV and RGB outputs and for install into another one at a later time. 

 

[the_crayon_king]

20 hours ago, Icelvlan said:

Cool will this be compatible with Odyssey 2?

The new boards and CPLD will be compatible. The code is what changes from console to console. So once flashed for the O2, Intellivision, etc then it will only work on that kind of console.

I still need 2 pallets for the O2. I made the default one based on math but I could use something more concrete.

 

16 hours ago, Reality Studio said:

 

Cool, I'll be testing it out on the Retrotink 5x.

I would be incredibly surprised if this ends up not working on the 5X. Considering even the broken sync works on the 2X. Still it will be good to know about everything.

 

@-^CrossBow^- It's kind of stupid to use a HDR cable with this kit anyway. You are doing an analog conversion of RGB into YPbPr when you could just put out YPbPr in the first place. I would expect that with the right series resistance Csync may work on the HDR but I really don't know why anyone would want to try that. If I knew the circuit they were using to strip csync from composite video I would be more sure of things.

 

[+-^CrossBow^-]

26 minutes ago, the_crayon_king said:

 

@-^CrossBow^- It's kind of stupid to use a HDR cable with this kit anyway. You are doing an analog conversion of RGB into YPbPr when you could just put out YPbPr in the first place. I would expect that with the right series resistance Csync may work on the HDR but I really don't know why anyone would want to try that. If I knew the circuit they were using to strip csync from composite video I would be more sure of things.

 

I don't disagree with that statement. But there are people who may not have the full RGB setup but are thinking about it but do have a set of HDR cables that they could use in the meantime. It just adds in an extra level of versatility as you can have both RGB and a means for component if needed. In my opinion, I couldn't really see any difference visually between the RGB output and YUV output from my Intellivision 2 that I configured for both. So either is a good solution in this case and anything is better than the current composite kits and the RF as well.

 

 

[the_crayon_king]

7 hours ago, -^CrossBow^- said:

I don't disagree with that statement. But there are people who may not have the full RGB setup but are thinking about it but do have a set of HDR cables that they could use in the meantime. It just adds in an extra level of versatility as you can have both RGB and a means for component if needed. In my opinion, I couldn't really see any difference visually between the RGB output and YUV output from my Intellivision 2 that I configured for both. So either is a good solution in this case and anything is better than the current composite kits and the RF as well.

 

 

Yea just using it on a toggle would be easier. If I could produce a 8 pin to YPbPr cable that would be ideal. Just break out 8 pin to RCAs I mean.