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ITC Colecovision Upgrades


CrossBow

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I've always had a Colecovision as one of the consoles that is pretty much at the ready since first putting all my consoles together in the game room. That said, the CV is one of the consoles that doesn't get much time as compared to most of the others. It should come as no surprise that my CV is also pretty heavily upgraded. It has a dedicated composite video output amp, RGB, the +5v RAM modification, and a short delay BIOS installed into it. But even with all of that, I've never been 100% happy with how it plays. It has some odd glitching with a few games here and there, and the RGB output while looking great, It doesn't quite compare as well as some of my other RGB consoles I've done. So... what does one do in a situation like that??

Well, if you are like me, you decide that some parts your purchased sometime ago (about a year back or more), can finally be put to use into a different spare CV that I had on hand. I technically own 3 Colecovision consoles. The other 2 were all stock and would good to have on hand for not only spares, but for testing things to help rule out the upgrades installed into my main CV.  But I don't need 2 stock consoles...

One of the spares has been in my closet of doom in the game room for over a decade and would only get pulled out on occasion for testing as noted above or to move it out of the way to get to something else in the closet. But it has always worked and actually always been in good physical condition. So I it was time to finally do something with it. This blog will detail what was done on this CV that gets so little use and how it will rise and become one of the most used consoles in my setup...

The first order of business was to replace the capacitors. Replacing the capacitors in the CV isn't that big of a task compared to some consoles as there aren't a ton of them. But what is a pain is that 3 of the caps are hiding within the RF modulator housing and require removing it to replace them. But the rest are easy enough to replace.

Here is an overview of the main board with the work done. Doesn't look like much but working on CVs requires a bit more patience than other consoles as the traces and pads on the CV are very fragile and can melt off with the solder easily when trying to remove components.

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Here is a picture of the bottom of the main board. The only items of interest here are the 2 capacitors near the top of the picture that I installed on the bottom of the PCB so the RF modulator doesn't have to be removed to service them in the future. You can also see the ESD protection boards that are installed on each of the two controller ports.

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The ESD protection boards were designed by Jimmy at Ruggers Customs who does a TON of services on lots of retro consoles, but his speciality is the Colecovision. The ESD boards solder to the bottom of the controller port pins and are designed using rectifier diodes, to redirect any high voltage spike to the controller pins to the main ground of the console protecting the controller IC chips which, are prone to damage easily from ESD. BTW you can cause a large voltage strike from ESD by just plugging in the controllers if there is enough charge built up on your body. These ESD boards can be purchased from Console5. Here is port1's ESD board in better detail:

ITCCV8003_P1_ESD_Detail.jpg.cea4f579099bba0eed9e29ad91fd3399.jpg

Here is the player 2 controller port ESD board in detail. BTW I use clipped sections of desolder braid/wick to connect the boards from the GND pad back to the nearest ground on the console on the bottom.

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Here is a picture of the wiring that was done for the new rocker switch that I also installed. The switches I found will fit into the original opening and only require having to modify the switch clip anchors a tiny bit for them to be used. You can't see it in the pic, but I've got a molex connector in the wiring so I can remove the top shell easily to service the console. This is because the new switch is installed into the top shell directly. I've had these rocker switches on hand for years as I bought a handful of them from the local electronics/radio operator store. Sadly they closed up permanently this past March 2024. 

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The F18A has been around for over a decade but only available in small batches here and there. It is an amazing upgrade to install into a CV. It is a drop in replacement for the VDP chip and provides crisp VGA output but also adds an additional feature where it increases the ability of the console to handle more sprites on the screen at once and reduce/eliminate flicker when playing games. I also replaces the video RAM setup in the console since it has its own vram directly on the PCB. There is also a scanline option that can be enabled. It actually looks pretty good compared to some other similar scanline modes I've seen. I actually added a wire that isn't visilbe in this picture that I ran back to the channel select switch on the RF modulator. This allows me to turn the scanline feature on/off from the rear of the console vs having to manipulate the dipswitch for it on the F18A. The model shown here is the newest version known as the Mk. 1. It is much smaller than the original F18A allowing for easier installs and includes a new VGA breakout setup you can see in the back of the picture and uses a flat flex cable to send the signals from the F18A back to the VGA.

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Here is a more detailed picture of the VGA breakout assembly. Again, you can see that the flat flex cable just slots into the small connector making it easy to connect up and remove the cable if the console requires future servicing. Just to the left of the VGA breakout is a new 3.5mm jack installed for audio. 

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Here is how everything looks at the rear of the console. You can see the VGA and 3.5mm audio jack on the left hand side here:

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Here is a better detail view of the VGA output and audio jacks. I will state that the VGA was a pain to install because the breakout requires that the VGA jack be installed internally within the console. As a result, the opening for it has to be made slightly larger all the way around vs the jack so that the male cable end will fit around it properly. That required a lot of filing, little by little to make it look nice and might have taken longer than most of the other work done on the console.

ITCCV8003_VGA_Aud_Ext_Detail.jpg.5222fde38e8f236e4cf26f5da9dee288.jpg

 

It might not seem all that much work was done, but it was a full days work of work that was put into this Colecovision. After a good cleaning and some UV protectant applied, it will now becoming the main CV used in the game room and the previous one will become the hot spare and additional testing CV console.

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I've got three CV's.

  1. A completely original model that works perfectly.
  2. A Phoenix which is what I use most of the time.
  3. A modded CV (composite only) that works, but the colors have a kind-of rainbow color shift. 

That 3rd one has been on my project pile for ages.  I did not do the mod, but I'm guessing that mod board has worn out.  One of these days, I'll open it up and see what I have.  I like to go in with at least a theory of what is wrong and how to fix it.  I suppose I should plan on replacing the composite mod board. 

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23 minutes ago, RickR said:
  1. A modded CV (composite only) that works, but the colors have a kind-of rainbow color shift. 

That 3rd one has been on my project pile for ages.  I did not do the mod, but I'm guessing that mod board has worn out.  One of these days, I'll open it up and see what I have.  I like to go in with at least a theory of what is wrong and how to fix it.  I suppose I should plan on replacing the composite mod board. 

Actually every CV I've added a composite upgrade into has that rainbow shift that can be seen with white text and sprites using white. The composite upgrades are just amplifiers that are attenuate the composite video that is generated inside the RF modulator to make it usable to actual TVs. I've tired all the composite kits and they all present that rainbow effect. That was one of the reasons I added the TMS-RGB to my other CV was because as I got better and better TVs and scalers to work with my consoles, the composite output began to look more and more flawed. We have the same situation with the Intellivision. That is what made the RGB board for that console so awesome was that it generated a new composite and s-video processed from the actual signals from the video processor. 

I guess what I'm saying, is that there isn't likely anything wrong with your composite upgrade that has been installed and what you are seeing is a result of what I described above. BTW if you can get a nice decent RF output from a CV on a modern display, you will also see that it has that same rainbow effect happening but is much more subtle through the RF. But yes, it is why some folks think the RF output from a CV looks better than the composite upgrades. And they aren't completely wrong about that in this case.

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I didn't know this, so thank you.  Come to think of it, I don't think I've ever seen composite output from a modded CV, so I have nothing to compare it to.  I may take a pic later to show you just to make sure this is the non-problem.

 

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Well, what I can do is fire up my other CV that has composite on it and see if that is what you are talking about? It was the main reason I wanted to go with something higher quality and put RGB into that one. As I had the composite already in place, I was able to run the composite signal from that board to my 9pin mini din for the RGB and that provided a compatible c-sync needed for Sega RGB cabling to work and also provide composite. But I also had a previously installed composite RCA jack. 

Point is, it can provide composite output from 2 different ways on the back of it and they both looked the same quality wise.

 

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Okay, yeah that is much worse than the effect I'm talking about. What I thought you meant was the rainbow effect that comes off the text and sprites that are white against black backgrounds? 

You can see what I'm talking about in the text on that title screen where is says 'Presents... Donkey Kong'

 

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OK, good.  At some point, I'll open it up and see what I've got.  Although I don't even remember how to open these without losing the front sticker. 

I should see if RF still works.  That will narrow it down a bit more. 

 

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RF works!  Sadly, it looks exactly the same with the white-ish color and shadowing to the right.  (But the rainbow text actually looks much better). 

I think that probably indicates a flaw in the CV itself...perhaps a recap needed. 

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13 hours ago, RickR said:

RF works!  Sadly, it looks exactly the same with the white-ish color and shadowing to the right.  (But the rainbow text actually looks much better). 

I think that probably indicates a flaw in the CV itself...perhaps a recap needed. 

The composite output is actually generated inside the RF modulator itself. That is why it has to remain in place or at least working in circuit somehow to get composite output. I'm wondering if there isn't some power issue in the console on the +12v side that might be causing that as the RF uses the +12v to power it if I recall. I know we tap the input power for the composite upgrade boards off the +12v inside the RF box. 

For reference... this is what DK looks like on my modern OLED in the game room from the F18A through my OSSC.

https://drive.google.com/file/d/1V17d9AZHoOeU8wsRHNPxONHgPvUaONAh/view?usp=sharing

Edited by CrossBow
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