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New Coleco RGB board?

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Tracing the expansion audio from pin31, according to the schematics I have, it should only be necessary to tap audio at pin 2 on the bottom of the board. This is the same pin that connects to C88 in the RF modulator.

 

So it would appear that as long as audio is taken from this point, you should have both system audio and expansion module audio.

 

Unless I am missing something?

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Yes if you tap from the C88 leg or equivalent you get both system and expansion audio. If you tap directly off of the sound chip the expansion sound will be very low.

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I went ahead and updated the document with most of the recommendations I have received. I will post the new link shortly and take down the old version. In an effort to keep all wiring on one side of the board, I am only going to document connecting to pin 2 under the RF. Since I am sure some people probably already have composite or s-video mods, they have likely already tapped C88 and can just reuse that connection. I appreciate the feedback from everyone.

 

I will still continue to adjust the document as time permits. I would like to potentially get some example scope plots and definitely recommendations for output jack installation into the document. I just have not had a chance to do this yet. Especially since I doubt many people are going to follow my personal method of installation.

 

Edit: New version is now up. I overwrote the original version so the same link should still work.

Edited by mobiusstriptech
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Test ROM:

 

attachicon.gifCV-Screen-Test.rom

 

Has some functionality - can move around, change overall screen color (push button), change block color (push one or other fire button). I think if you push a certain button (7?) on both controllers, you get a very crude drawing program.

 

 

Would it possible to have a menu to select the color of the screen, i.e. Red, Green, Blue, White? Then entire screen would be that color until button was pressed. I know there are multiple greens and its hard to tell if you have the right color or not.

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Would it possible to have a menu to select the color of the screen, i.e. Red, Green, Blue, White? Then entire screen would be that color until button was pressed. I know there are multiple greens and its hard to tell if you have the right color or not.

 

It's an old program... you'll have to make your own if you want it fancier. I found the original instructions from another thread. The colors are in order for the top half of the screen, so you can compare to an emulator's color chart (if they're showing the colors in order, that is). Note that there's sometimes some little blocks that don't change color, for some reason. It is what it is...:

 

The main screen shows all 16 colours in blocks in two ways. The top half shows the colours in order, from 1 to 15, then 0. The bottom half also shows all of the colours (except one of the blacks), but with similar colours beside each other, to better highlight the differences (or similarities) between each, for instance, showing all three "green" colours in a row.

 

A cursor also flashes on the screen. The joystick can be used to move the cursor around the screen. Pressing the main fire button cycles the colours up, and pressing the secondary fire button cycles the colours down. The colour of the whole screen will change if a number is pressed on the keypad. Only numbers 1 through 9 are accepted, but if you press and hold a key on the second keypad (1 through 8 ), then press a number key on the first keypad, the numbers will be added (to access colours 10 through 15). If you don't want to use the second keypad, you can of course manipulate the blocks individually.

 

There is a little bonus added. The program uses mode 3, which is a 64 x 48 grid (of 4x4 pixels). Press the 9 key on the second keypad to access it. Now that I think about it, the control scheme is fairly non-user-friendly. icon_wink.gif Anyway, using the first keypad, the colours of each 4x4 pixel can be changed the same way as described in the previous paragraph (sorry, the wholesale colour change is not available). There you have it - a brute-force pixelated drawing program. icon_smile.gif

 

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Thanks 5-11under. I asked if someone could write one, as I still can't figure out how to make screen white using that rom.

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Thanks 5-11under. I asked if someone could write one, as I still can't figure out how to make screen white using that rom.

 

That's the 15th block on the screen, so you'll need to add up to 15. For instance, press and hold 8 on keypad #2 (like a shift key), then press and release 7 on keypad #1, then release keypad #2.

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Its the photo. Real life the white is perfect. Sort of hard to get the blues to be what they really are in the photo too.

post-27883-0-32846700-1523913605_thumb.jpg

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Colors are slightly different when connecting to Sony PVM vs. OSSC, so adjust POTs when connected to the device you plan to use the Colecovision on the most.

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The big batch is about halfway gone. I was thinking about doing a batch about 4x the size of this one just to ensure I won't run out for a very long time. The popularity of this board has been much higher than I ever could have anticipated.

 

However it looks like there may be a few more people mass producing these soon. So I am on the fence about whether I want to make more when these run out.

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So I don't have an oscilloscope to tune this... can I try to adjust it while the the unit is on and connected to the TV?

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Here is emulator screen shot of the colors. If using Kiwi's awesome video test rom's try to get something pretty close to below. As long as you can see a differences between the various color shades you will be happy.

 

I used a couple of games as well, Bank Panic is good, so is Gradius, Sky Jaguar and Pac Man Collection. If the colors you dialed in look good for all these then I think you will be overall very happy.

 

Good to compare to F18A as well.

 

Anyone have BlueMSX, it would be good to see how it looks in that emulator? Or any others.

post-27883-0-67117000-1524192305_thumb.png

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If you did the 5v ram mod, then you can take it from the line you added. Otherwise the middle ceramic cap by L3. Reference number C42 should be +5v. Last place is directly from the +5v in from the power supply.

 

There are multiple other places but those are the ones that come to me off the top of my head.

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