mobiusstriptech Posted January 28, 2020 Share Posted January 28, 2020 What is displayed on the LCD screen of the OSSC when you connect it? Quote Link to comment Share on other sites More sharing options...
zaphro72 Posted January 28, 2020 Share Posted January 28, 2020 (edited) 5 hours ago, Mister Fab said: Hi all, I just found this topic while searching a way to modify my Colecovision. I got the console when it came out it france in 1983. So it is a PAL RGB / SCART version It was still working on my 2013 Samsung 55" smart TV, as there were a SCART connector on it, but I just replaced my TV for a Philips 65", and no more SCART on it. I bought an OSSC 1.6, which works perfectly with RGB SNES (after I modified the AV cable to use Luma sync ) But when I connect the Coleco, I can get sound, the OSSC shows a sync but I can't get an image. It seems the Coleco only has C-sync which is not compatible with OSSC. Has someone already faced that case? https://www.retrorgb.com/frenchrgbconsoles.html This might help you out a bit and is what the people on the OSSC board were talking about (I think) in regards to it might not be true RGB out of the console and just composite converted to RGB, which the OSSC does not like Edited January 28, 2020 by zaphro72 accuracy Quote Link to comment Share on other sites More sharing options...
ChildOfCv Posted January 28, 2020 Share Posted January 28, 2020 Doesn't the SECAM version still use the 9929 though? Its output is analog Y, Pb, and Pr, almost directly compatible with component video output other than a burp at the color burst. The Citrus board then does the necessary summing to get RGB and sync. So in theory, since you're getting video before the modulator, the nature of the modulator should be irrelevant. Quote Link to comment Share on other sites More sharing options...
Mister Fab Posted January 29, 2020 Share Posted January 29, 2020 (edited) These are the two "official" wirings I have found on Colecovision.dk I checked my working cable (tested on a cathodic TV) with a ohmmeter, and here's what I got: Pin 4 and 5 (orange and black wires) are inverted on the DB15 side if I compare to the official wirings, and I can't understand how RGB blue and +12V can be inverted. I tested the voltage on scart pin 8, I get 12V as it should be. When I plug the cable to the OSSC, I get this on the screen, but black screen out: Edited January 29, 2020 by Mister Fab Quote Link to comment Share on other sites More sharing options...
Mister Fab Posted January 29, 2020 Share Posted January 29, 2020 (edited) Here are two hi resolution pics of the motherboard (91209 rev.B) Edited January 29, 2020 by Mister Fab Quote Link to comment Share on other sites More sharing options...
ChildOfCv Posted January 29, 2020 Share Posted January 29, 2020 Cool, though I was thinking about the situation of using the Citrus3000Psi add-on and going through that. I had forgotten that they have SCART out (isn't there an old version that actually modulates TV output?) Anyway, I can see from first glance that the board has the YPbPr to RGB summing networks and amplifiers for the signals, but I'll have to map it out to figure out what it does with sync, and where everything goes. Fun! Quote Link to comment Share on other sites More sharing options...
emmanuelf Posted January 29, 2020 Share Posted January 29, 2020 You are crazy ? I will be able to put a scope on one soon. Quote Link to comment Share on other sites More sharing options...
ChildOfCv Posted January 31, 2020 Share Posted January 31, 2020 On 1/29/2020 at 5:50 AM, Mister Fab said: Pin 4 and 5 (orange and black wires) are inverted on the DB15 side if I compare to the official wirings, and I can't understand how RGB blue and +12V can be inverted. Well, preliminary work shows that there's definitely a power trace going to pin 4 on the PCB. So either these sites are wrong, or there are different pinouts for different revisions. Another note is that pins 6, 8, and 14 are connected, possibly to that fat ground trace that burrows underneath from the right. BTW, if you could get a picture on the other side of that trimmer resistor so that I can see the traces there, that would be great. Quote Link to comment Share on other sites More sharing options...
Mister Fab Posted January 31, 2020 Share Posted January 31, 2020 Wow!! you impress me ChildOfCv!! Just to say, I practice electronics, but I have limited knowledge. But if you need any signal test, I have an oscilloscope, so if you tell me where to test I can give you all the results. I will take very detailed pictures this afternoon Quote Link to comment Share on other sites More sharing options...
Mister Fab Posted January 31, 2020 Share Posted January 31, 2020 Here are the pics, I took quarter by quarter of the board. Tell me if you need more details. Quote Link to comment Share on other sites More sharing options...
ChildOfCv Posted February 1, 2020 Share Posted February 1, 2020 So, pin 10 is +5V and pin 2 is +5V through a 160-ohm resistor. One thing I need is the part number of those transistors. Many are MPSA13, but there are others that I can't read, and I'm sure at least some of them are PNP. Quote Link to comment Share on other sites More sharing options...
ChildOfCv Posted February 1, 2020 Share Posted February 1, 2020 U29 and U30 (the 4066 analog switches), are pins 5, 6, and 13 all connected between the two of them? (Are any of them? ?) Quote Link to comment Share on other sites More sharing options...
ChildOfCv Posted February 2, 2020 Share Posted February 2, 2020 So, here's the probable pinout: 1 - Red 2 - +5V (160 ohms) 3 - Green 4 - +12V 5 - Blue 6 - Gnd 7 - Amplified audio? 8 - Gnd 9 - R-Y component 10 - +5V 11 - B-Y component 12 - unknown (possibly unconnected) 13 - Y component 14 - Gnd 15 - Unamplified audio Here's a rough schematic that probably bears some resemblance to the actual circuit Quote Link to comment Share on other sites More sharing options...
ChildOfCv Posted February 2, 2020 Share Posted February 2, 2020 Also, there's this page about the important pinouts. Notice that the Y component is used as composite sync. https://www.nightfallcrew.com/14/06/2009/cbs-colecovision-secam-rgb-hackcbs-colecovision-secam-rgb-hack/ Quote Link to comment Share on other sites More sharing options...
emmanuelf Posted February 2, 2020 Share Posted February 2, 2020 (edited) So you preferably need a sync separator before the OSSC input. Worth a try. (see the ready to use "syncblaster" which has the proper 75ohm output level). And it would be perfectly coherent for why it work on a "normal" TV but not on the OSSC as a normal TV have the CSYNC imput common with the CVIDEO input. Edited February 2, 2020 by emmanuelf sync blaster Quote Link to comment Share on other sites More sharing options...
emmanuelf Posted February 2, 2020 Share Posted February 2, 2020 Is is astounding to see how clean and modern is the design of the console and the PCB for the time being. And mainly done by one man. Quote Link to comment Share on other sites More sharing options...
Mister Fab Posted February 2, 2020 Share Posted February 2, 2020 Hi, I'll send tomorrow the pcb on both sides, I had some time today to draw it from the board on several layers with paint.net. Still in progress, but I hope it will help. Quote Link to comment Share on other sites More sharing options...
Mister Fab Posted February 2, 2020 Share Posted February 2, 2020 @ChildOfCv, there's no pnp transistor, only npn. F2N3904 F2N3906 MPSA13 Quote Link to comment Share on other sites More sharing options...
ChildOfCv Posted February 3, 2020 Share Posted February 3, 2020 Some more interesting info: On NTSC boards, pins 41 and 42 on the expansion board are unconnected. Pins 31, 32, and 33 are external audio, external video enable, and external video composite. The SECAM board changes all of that. Pin 41 is now external audio. 42 is external video enable. Pins 31, 32, and 33 are the YPbPr signals. So the SECAM Expansion Module 1, if it exists, apparently has much better video than the NTSC one does. And likely leagues better than the Atari 2600 SECAM. Quote Link to comment Share on other sites More sharing options...
ChildOfCv Posted February 3, 2020 Share Posted February 3, 2020 (edited) 2 hours ago, Mister Fab said: @ChildOfCv, there's no pnp transistor, only npn. F2N3904 F2N3906 MPSA13 3906 is PNP More importantly, impressive work mapping those traces. Especially underneath the connector and ICs. I had to do a lot of puzzling, process of elimination, and outright guessing. I see that one of the traces seems to abruptly end underneath the connector though. Have you just not found its destination? It may be connecting to one of the two vias that come up underneath. Here's a closeup of that area with my doodles. The two red dots are the vias. Edited February 3, 2020 by ChildOfCv Quote Link to comment Share on other sites More sharing options...
ChildOfCv Posted February 3, 2020 Share Posted February 3, 2020 9 hours ago, emmanuelf said: So you preferably need a sync separator before the OSSC input. Worth a try. (see the ready to use "syncblaster" which has the proper 75ohm output level). And it would be perfectly coherent for why it work on a "normal" TV but not on the OSSC as a normal TV have the CSYNC imput common with the CVIDEO input. Well, after reconciling a few things with Mister Fab's awesome efforts, I think even that may not be necessary. That amp on pin 7 seemed odd, and after reconciling the fact that pin 15 does not mix with it, I'm now convinced that this is the CSYNC generator. So here's a PDF based on the combined effort. Pinout is included near the connector. VideoMultiplexer-A-V Multiplexer.pdf Quote Link to comment Share on other sites More sharing options...
ChildOfCv Posted February 3, 2020 Share Posted February 3, 2020 One more thing: I have U29 pin 6 and U30 pins 6,5, and 13 connected, but nothing to drive them. Could you check if they're connected to pin 7, or possibly to Q24 directly? Quote Link to comment Share on other sites More sharing options...
emmanuelf Posted February 3, 2020 Share Posted February 3, 2020 10 hours ago, ChildOfCv said: Some more interesting info: On NTSC boards, pins 41 and 42 on the expansion board are unconnected. Pins 31, 32, and 33 are external audio, external video enable, and external video composite. The SECAM board changes all of that. Pin 41 is now external audio. 42 is external video enable. Pins 31, 32, and 33 are the YPbPr signals. So the SECAM Expansion Module 1, if it exists, apparently has much better video than the NTSC one does. And likely leagues better than the Atari 2600 SECAM. Ok mysterious difference between the RGB version for the SECAM market and the others are no longer mysterious. The adaptation needed for the super game module is now obvious. Yes Expansion Module #1 exist and is specific to this model. Beside the same adaptation for external sound, that explain the "no sound/no picture" when PAL or NTSC Expansion Module #1 is plugged into a RGB model. How things are done in #1 remain to be seen. A YPbPr TIA clone ? I will open one and take pictures. Quote Link to comment Share on other sites More sharing options...
Mister Fab Posted February 3, 2020 Share Posted February 3, 2020 (edited) Hi guys, I continued my work on the other side of the board. I didn't map the full board for now, but I'll continue to finish the full board, hoping it can be usefull to someone in the future. I will shrare the paint.net file when I'll have finished, it is easier to hide each layer when looking for something particular. I made a few modification on the component side to the tracks under the A/V connector, I found some errors while I started to map the back side. Let me know if you see some incoherences so I can correct them. Edited February 3, 2020 by Mister Fab Quote Link to comment Share on other sites More sharing options...
Mister Fab Posted February 3, 2020 Share Posted February 3, 2020 (edited) I took a picture of each transistor, I think I didn't make a mistake about they're all npn. Aren't collector and base inverted on pnp? Edited February 3, 2020 by Mister Fab Quote Link to comment Share on other sites More sharing options...
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