Lumacode for the Intellivision

[copperdragon]

Lately I have been designing many mod boards for various retro systems to extract digital video infromation to be fed through a special upscaler to get pixel-perfect HDMI. This whole Lumacode system is working nicely and I would like to expand its application to the Intellivision also.

My main problem is that I don't have this console and I actually don't want to buy one if that can be avoided. 

 

I have done all possible preliminary research and planing and I am pretty confident that my idea will work. But before going any further, I would need some help from an owner of an Intellivision who also has an oscilloscope. Maybe soneone here is willing to help in this project. First thing would be to get some signal measurements from the actual hardware. If this continues to look good, I will build some prototype boards and send them out to possible voluntieers to try them. Everything will be open source, so anyone can build their own board.

 

Installation of the mod should be possible with basic soldering skills. The board goes to the underside of the main board directly under the STIC chip. It is actually pretty tiny and if everything goes as planned it would look like this picture.

 

[+KylJoy]

I have a scope and I would be willing to assist.  No problem.

[copperdragon]

Thank you, that is great. I assume that you have an NTSC Intellivision of which I would need measurements of the following signals from the STIC (AY-3-8900-1):

 

Clock     Pin 15

V1         Pin 22

V2         Pin 21

V3         Pin 18

V4         Pin 16

V5         Pin 19

 

It is important to get the time relation between the Clock and each of the V pins. Best to set the trigger to rising or falling edge of each V pin in turn and take a picture of this signal together with the clock signal. This will give us 10 pictures in total which sould be all I need for my planning.

 

[aotta]

Happy to ear you @copperdragon are working on Inty too, i use your project in some of my commodore and they are super! 

I already use Rgbtohdmi in a couple of my intellivision with yuv-analog board and keeping signals from stic, but hdmi output is not perfect, so happy to help you in some way if needed

[tlindner]

I'm a big fan of LumaCode and have your board for the 2600. Additional options for the Intellivision are always nice.

 

But it should be noted that tapping the digital signals and feeding them directly to a RGB2HDMI already produces a pixel perfect HDMI signal.

 

No system side processing needed.

[EdgeFaction]

Super excited for this project! The more direct from chip RGB options we have the better. As it is now, there is not anything readily available.

[+-^CrossBow^-]

Sign me up!!! Although I have a much older analog scope that isn't really able to do much other than get basic signals. Also, any reason for sticking with the STIC and not taking the signals from the color IC instead? The main reason is that on the model 1, the color IC is closer for signal runs back to the RF section. Also, far as I know, the color IC and usually the STIC are always in sockets. So instead of soldering to the bottom, wouldn't a normal interposer work better here? Most model 2 units don't have heatsinks on the STIC so there is room I think for it and obviously there is a lot more space on the model 1 for such a solution? Although if you develpoed something to use the color IC instead, that wouldn't be an issue with space since there isn't a heatsink to deal with?

 

[copperdragon]

Are you sure that the STIC is always socketed? In this case an interposer board would indeed be simpler for installation. 

I am not an expert of different machine variants, but I had the impression that on PAL machines there is no color IC, but everything is done with a different circuit instead. Do you have any more information on this?

[walldog1]

On 8/2/2024 at 12:45 PM, -^CrossBow^- said:

Also, far as I know, the color IC and usually the STIC are always in sockets.

From my experience, all STIC chips are in sockets in the model I's. I have less experience with the model II's, so I can not say for sure.

 

On 8/2/2024 at 2:45 PM, copperdragon said:

Are you sure that the STIC is always socketed?

 

[+Lathe26]

On 8/1/2024 at 1:16 PM, copperdragon said:

Lately I have been designing many mod boards for various retro systems to extract digital video infromation to be fed through a special upscaler to get pixel-perfect HDMI. This whole Lumacode system is working nicely and I would like to expand its application to the Intellivision also.

My main problem is that I don't have this console and I actually don't want to buy one if that can be avoided. 

 

I have done all possible preliminary research and planing and I am pretty confident that my idea will work. But before going any further, I would need some help from an owner of an Intellivision who also has an oscilloscope. Maybe soneone here is willing to help in this project. First thing would be to get some signal measurements from the actual hardware. If this continues to look good, I will build some prototype boards and send them out to possible voluntieers to try them. Everything will be open source, so anyone can build their own board.

 

Installation of the mod should be possible with basic soldering skills. The board goes to the underside of the main board directly under the STIC chip. It is actually pretty tiny and if everything goes as planned it would look like this picture.

 

I've been working on a project to accurately measure the colors from the Intellivision (plan to measure from multiple Intellivisions).  I have oscilloscopes, multiple vectorscopes, an NTSC/PAL signal generator, multiple RF demodulators (one is studio-grade), and some other related equipment that would be partially automated using SCPI, SNMP, and serial communication.  The plan was to be much further along, but life has repeatedly gotten in the way (grrr).  I am willing to help, though at present I am dealing with replacing a failing NAS server which takes priority.

[+-^CrossBow^-]

On 8/2/2024 at 1:45 PM, copperdragon said:

Are you sure that the STIC is always socketed? In this case an interposer board would indeed be simpler for installation. 

I am not an expert of different machine variants, but I had the impression that on PAL machines there is no color IC, but everything is done with a different circuit instead. Do you have any more information on this?

Again, far as I know the STIC seems to always be in a socket on both model 1 and model 2 units. That said, perhaps I've just happen to get lucky in that the model II units I've worked on just always had their STIC in a socket?

 

Another thing to be aware of with the STIC is that the +5 voltage on it is strange as it will sometimes read a bit too high or low since it seems to not be directly connected to the main +5 and instead is switched on. Because of this, in the case of the current RGB boards, it can cause some goofiness and even Crayon King has since advised that +5 get pulled from somewhere else on his boards.

 

If the PAL units don't have the color IC, then I can see where the STIC would be the only universal option. But I do think at least in the case of the NTSC consoles I've seen and services, that the STIC being in a socket would make for a much easier setup. And if the STIC isn't in a socket, then it needs to be put into one given that the STIC are a high failure IC in the consoles.

 

 

 

 

 

[copperdragon]

It is true that an interposer board can make installation solderless. But it will add 4mm to the overall height. Could this be a problem for certain machines?

Just to summarize pros and cons for the interposer board:

 

Pro:

Solderless installation

 

Con:

May not fit because of added height

STIC may not be socketed 

Making the mod board itself is much more difficult and more expensive 

 

Unfortunately I can not just create a single PCB to which an optional socket can be added. For the variant that goes to the underside of the mainboard everything must be mirrored.

So if there is no other compelling reason, I will keep my original plan to stick the board to the underside of the main board.

 

 

Also I just became aware of another problem: The sync pulses generated by the STIC seem to be quite a mess. This causes severe imcompatibilties with TVs and upscalers (notable the OSSC). So some more ideas are needed to overcome these problems.

[+-^CrossBow^-]

3 hours ago, copperdragon said:

Also I just became aware of another problem: The sync pulses generated by the STIC seem to be quite a mess. This causes severe imcompatibilties with TVs and upscalers (notable the OSSC). So some more ideas are needed to overcome these problems.

The sync issues is why the initial earlier runs of Yannick's boards had issues with OSSC and why the first run of Crayon's RGB boards didn't work with the OSSC either. I believe Crayon decided to create a brand new sync pulse on his boards and that is why his last design now works on everything to the best of my knowledge. But yeah, the Sync on the Intellivision is a right mess. Most of my modern TVs will display a decent picture through RF, but the image is constantly jittering up and down the entire time due to the odd sync pulses and it was why I sought out to AV upgrade my Intellivision in the first place years ago.

 

On the height issue, I can tell you that the ONLY model that would present a problem would be the model 2. The model 1 has space for it I'm pretty sure. The model 2 would be trickier as the STICs in those consoles and in fact all of the ICs in the model 2, do not have the heatsinks installed on them. You can use the chips with the heatsink into a model 2 but it will ONLY fit if you then solder the chip directly to the board to account for the extra height by NOT using a socket. I've had to do that in a few STIC replacements in model 2 consoles. So I guess what I'm saying is that you basically the have the space of the heatsink plus the STIC itself to work with in total on the model 2 console. But on the model 1 I think you would be fine. 

 

I'm going to go look through my picture library on model 2 consoles to see if they did in fact have the STIC in sockets on each one as I'm pretty sure I've stated. 

 

Okay so I just took at a look into all the model 2 units I've serviced. It isn't a huge sample by any means, but I've done about a dozen total over the years. And every single one of them had the follow three ICs in sockets.

 

STIC

CPU

RAM 3-9600

 

That said, I stand corrected in that only a few of those actually have their color ICs in a socket on the model 2. So it would seem that the STIC is always in a socket on the NTSC models. But I cannot say if the same is true of the later made INTV consoles from the late 80s. I've only service about 3 ever from that timeframe as they just don't seem to come up that often for me.

[copperdragon]

This is now the most insane PCB I have ever started to design. This provides the possibility to use it for an interposer board: Solder a 40-pin socket with machined pins into the holes, just like for most of my lumacode boards. But you can also solder it to the underside of the mainboard (like for the NES). For this you need to rotate the board by 90 degrees and use the vertically arranged pin holes instead. One minor problem is that the hole on the top right corner (which is duplicated to the bottom left) would clash with some other signal. So there is a solder jumper on the underside where you need to close one contact depending on the mounting option. 

 

This design is now so squeezed down that I will very likely need a 4-layer board  (I have not yet done any traces yet). But I think this is totally worth it