Unstablewarpfield Posted February 23, 2017 Share Posted February 23, 2017 Hi all, Lately I have been fiddling around with an Intellivision RGB mod. I have a PAL unit and decided to go with these schematics http://www.nightfallcrew.com/wp-content/uploads/2013/03/intyrgb.png I build a test version on a breadboard and it worked flawless. I then proceeded to make a pcb board for this mod. This is when the trouble started... I chose to remove the LM1886N color IC from the intellivision main board and installed a socket so I can easilly reverse back to the original. When I measure my voltages on the rgb lines coming out of the mod it shows me 0.63V for both red and blue. On the green line I measure 0.87V, which is a little high I believe. I went on to see where this high signal came from, and I found that all of the signals coming into the 74hct244 IC are about 0.24V. All of them, except the signal coming from pin 15 on the socket where the original LM1886N used to be. That gives me 2.91V. This means that one of the signals for green (according to the schematics) being fed into my 74hct244 is much higher then every other signal. When I test the mod it gives me a pretty sharp image, but on the boot screen (can I call it like that?) the second square block which is supposed to be yellow-ish displays as black. The screen itself also seems a bit too green. My question to some of the intellivision wizzards on here... what are the normal voltages coming off of those pins on the LM1886N? Is it normal to have such a high value on one of the three pins for green? It has been bugging me for a while now and I would like to close up on this mod and move on to my videopac g7000, but not before my inty works properly! Hope someone can give me a clue... Cheerz! 1 Quote Link to comment Share on other sites More sharing options...
Unstablewarpfield Posted February 23, 2017 Author Share Posted February 23, 2017 Just took a picture of what the image looks like now. The photo makes the blue and red look a bit odd. In reality they look fine. The sharpness is epic, but as you can see, the colors are off... 1 Quote Link to comment Share on other sites More sharing options...
+5-11under Posted February 23, 2017 Share Posted February 23, 2017 Is there a connection missed/messed? Keying in on the third bar initially, which should be bright green, but is black... . Try to get that color bar working first, and see what you have. /not an Intellivision wizard... . Quote Link to comment Share on other sites More sharing options...
Unstablewarpfield Posted February 24, 2017 Author Share Posted February 24, 2017 Thanks for the reply :-) The third bar is indeed what I ment in my OP. I said second, but it is indeed the third bar. The second is not supposed to be orange either and something tells me that as soon as the light green color pops on it will change the colors of the second and third bar, as well as the background. My knowledge about electronics and how logic gates work all together is limited so I am diving into the matter as we speak. I checked all connections and continuity on the MOD pcb and on the main board. Everything seems fine. No shorts either. It can't be a coincidence that the green output is a bit high, and that a light green color appears to be missing. I wish I knew more about the way these three green signals work so I can narrow down the problem. Quote Link to comment Share on other sites More sharing options...
GroovyBee Posted February 24, 2017 Share Posted February 24, 2017 Can you post a picture of the top and bottom of your PCB? It must be detailed enough to show the tracks. Quote Link to comment Share on other sites More sharing options...
mr_me Posted February 24, 2017 Share Posted February 24, 2017 How does it look if you return it back to original? Do you have a schematic to see the source of that pin 15 signal. Quote Link to comment Share on other sites More sharing options...
Unstablewarpfield Posted February 24, 2017 Author Share Posted February 24, 2017 (edited) The PCB I designed is this. Keep in mind that this is me doodling around in Eagle. I have never tried something like this before, and probably violated many rules of laying out a board like this, but I do know that the circuit works, since I tested it out on the bread board and colors were as they should be. The piece of ground in the middle along the central powerline (near R9, R11 and R12) is connected through a single wire to the larger copper fill on the board, which acts as GND. According to the schematics here, is pin 15 connected to the clock? I have read (I believe on this forum somewhere) that this schematic contains errors in it. Also, whenever I search for the U10 IC I can find the data for the LM1886N, or for the AY-3-8915. Are they thesame? Edited February 24, 2017 by Unstablewarpfield Quote Link to comment Share on other sites More sharing options...
mr_me Posted February 24, 2017 Share Posted February 24, 2017 (edited) You're going to need a schematic of your PAL Intellivision. [They are different than NTSC Intellivisions where it comes to colour. The ntsc ay-3-8915 was replaced by a set of chips to make PAL colour in most PAL intellivisions. Some had a PAL daughterboard.] Edited February 24, 2017 by mr_me Quote Link to comment Share on other sites More sharing options...
Unstablewarpfield Posted February 24, 2017 Author Share Posted February 24, 2017 I guess this is the IC you mean? At least... that is what I pulled out. The LM1886N. This is the only PAL schematics I have found so far. Unfortunately the resolution is quite small and it is hard to make out the details. Quote Link to comment Share on other sites More sharing options...
mr_me Posted February 24, 2017 Share Posted February 24, 2017 There's several chips involved with PAL colour. But only one for NTSC colour. How does it work when you return it to original condition? If it works correctly, the problem might be with your board. If its the same incorrect colours then the problem might be on the intellivision board. Quote Link to comment Share on other sites More sharing options...
Unstablewarpfield Posted February 24, 2017 Author Share Posted February 24, 2017 That thought has occurred to me mr_me. The thing is... being inexperienced as I am... The LM1886N got damaged while extracting it. I have ordered a new one and will be able to test that out somewhere this week when it comes in. I'll get back to you as soon as I know more. Thanks for thinking along with me :-) Quote Link to comment Share on other sites More sharing options...
+5-11under Posted February 24, 2017 Share Posted February 24, 2017 You could check each of the ladder lines (R1-R3, 9-11, 17-19), one at a time, by temporarily putting a resistor in parallel with the one already there. You would need to check all 16 colors. If nothing changes, there's likely an issue with that section. Quote Link to comment Share on other sites More sharing options...
Unstablewarpfield Posted February 25, 2017 Author Share Posted February 25, 2017 (edited) Just received the new LM1886N chip. Fast shipping! Anyways, I checked the image and it was super noisy. When I reinstalled the RF shielding the colors were displayed normally on RF output. This means that either the RGB mod schematics are faulty (which I doubt) or there is a short somewhere on my pcb I guess. The story continues. I might try that trick with the parallel resistors 5-11under. If anyone has any other ideas I'll be glad to hear them. Edited February 25, 2017 by Unstablewarpfield Quote Link to comment Share on other sites More sharing options...
Unstablewarpfield Posted February 26, 2017 Author Share Posted February 26, 2017 (edited) Bingo! I review my soldering work again and there was an extremely small blob of solder that caused a bridge between two inputs. Now the colors are working like they should :-) There is however a minor effect visible that I have also seen from time to time in several other consoles I modded. As an example I took a picture of this number in SNAFU. The picture does not show it very clear, but the blue number has a white-ish border around it, following the contours of the number. Could this be a sync related issue? It might be worth mentioning that I measure my CSYNC voltage a bit over 4V. Might it be bad shielding in a cable? I connect the console through an xrgb mini framemeister to a samsung LED tv. Any help is appreciated :-) Edited February 26, 2017 by Unstablewarpfield Quote Link to comment Share on other sites More sharing options...
Unstablewarpfield Posted February 26, 2017 Author Share Posted February 26, 2017 (edited) And... also here it appears I was a bit too hasty in asking for advice... I reduced the sharpness of my tv from 50 to about 15. That took care of the outlines. I will arrange sharpness through the xrgb mini if needed. Still need to connect the audio and I think we can call it a day on this one Edited February 26, 2017 by Unstablewarpfield 1 Quote Link to comment Share on other sites More sharing options...
Unstablewarpfield Posted February 26, 2017 Author Share Posted February 26, 2017 (edited) And to close this down... Some last pictures of the final result. The audio still has quite some noise in it, but I think this is due to the use of unshielded cables. Since I have two neo geo scart cables that are virtually noise free I will wire it up to accept the neo geo scart cable and I hope it will improve things even more. Now... onto the Videopac Edited February 26, 2017 by Unstablewarpfield 5 Quote Link to comment Share on other sites More sharing options...
Unstablewarpfield Posted May 12, 2017 Author Share Posted May 12, 2017 One last post in this topic. There was still some audible noise in the sound when I did this mod. Also some video noise was present. I know this mod is supposed to give a better result so in the end I decided to have a batch of pcb boards made. Installed them yesterday and the image quality is even better then with my home-etched pcb! I run this mod through an xrgb mini and have perfect video and audio quality from my Intellivision now. Happy! 1 Quote Link to comment Share on other sites More sharing options...
First Spear Posted May 12, 2017 Share Posted May 12, 2017 The success stories are always awesome. Thanks for sharing your epic effort! I am still waiting to see if I can get an RGB/HDMI/DVI mod for my NTSC unit... One last post in this topic. There was still some audible noise in the sound when I did this mod. Also some video noise was present. I know this mod is supposed to give a better result so in the end I decided to have a batch of pcb boards made. Installed them yesterday and the image quality is even better then with my home-etched pcb! I run this mod through an xrgb mini and have perfect video and audio quality from my Intellivision now. Happy! Quote Link to comment Share on other sites More sharing options...
JohnPCAE Posted May 13, 2017 Share Posted May 13, 2017 A long time ago I bought a DVD called Video Essentials. It's for calibrating your TV to get the most accurate picture. One of the things they stress is to turn the sharpness setting all the way down as it distorts the picture from what was actually recorded/broadcast. Quote Link to comment Share on other sites More sharing options...
+Rick Reynolds Posted May 26, 2017 Share Posted May 26, 2017 Hey guys, I have some questions about an RGB mod I just installed on my inty II. I installed the one described at this site: http://retrorgb.com/intellivision.html Colors aren't quite right. I see yellow on the menu screen for the LTO flash instead of the normal orange, and some other weirdness. I saw earlier in this thread that someone mentioned a soldering sloppiness that caused color problems. I wonder if I've made a similar mistake? Anyway, I'll post some pictures tomorrow when I'm at the CORGS show with my inty. Sent from my iPad using Tapatalk 1 Quote Link to comment Share on other sites More sharing options...
Unstablewarpfield Posted May 29, 2017 Author Share Posted May 29, 2017 If you have any bridges like I had... it will help to carefuly check your soldering work again. In the end I ended up having some pcb's made and haven't looked back since. Much better than etching my own boards. Quote Link to comment Share on other sites More sharing options...
+Rick Reynolds Posted May 31, 2017 Share Posted May 31, 2017 I installed a board from here: http://retrorgb.com/intellivision.html I was planning on taking some pics while at CORGS this past weekend to illustrate the color questions I have. But a wire came loose about half-way through the show. I've fixed it tonight and added some strain relief to hopefully keep it from breaking again. I'm hoping to get some pics of the screen tomorrow night. I emailed the board maker with some questions, and he indicated that the colors used by the board are chosen from a specific palette - shown in this posting: http://atariage.com/forums/uploads/monthly_10_2012/post-34079-0-22599900-1349323365.gif So I'm now wondering if I've got it installed correctly and the colors are just what they are based on this palette. The main color that seems wrong is the orange on the main screen of the LTO Flash cart. It shows up as a pretty clear yellow instead. But some (many?) games look pretty good to my eye. Anyway, I'll get some pics tomorrow night. Quote Link to comment Share on other sites More sharing options...
glazball Posted May 31, 2017 Share Posted May 31, 2017 (edited) Did your board come from Fred Konopaska (juice2839 on the forums)? He did the install which had minor color issues through RGB, most notable in Shark! Shark! When the jellyfish come out, they are the same color as the background water making them very hard to see (through RF they are purple). I brought it to his attention and he gave me the same response about the color palette, and I just decided to live with it rather than send it back to him (with no clear fix in mind). He has since had a falling out with AA, and I've been eager to see if others have had the same problem with his RGB board. For the most part though, it has worked really well. Edited May 31, 2017 by glazball Quote Link to comment Share on other sites More sharing options...
+Rick Reynolds Posted May 31, 2017 Share Posted May 31, 2017 Yep, it's Fred's board. Quote Link to comment Share on other sites More sharing options...
glazball Posted June 1, 2017 Share Posted June 1, 2017 Sounds like it might be hooked up fine, just a problem with either a) getting RGB out of the Intellivision by anyone or b) Fred's design. I'm not technical enough to know, but if you confirm the hard-to-see jellyfish (have to get to level 5 to bring them out), we'd know it's just the board design. Or, if you have any other examples of colors being off, I'll try on my end (I don't have the flash cart you mentioned). I don't suppose much support is forthcoming, after reading through the thread about his Say Game Module. He seems to have burned his bridges here and I'm not sure why. For a few extra bucks? He seemed modest and pretty talented from my interactions with him so it's pretty sad to see. I'd love to see your pics or hear about any developments. Quote Link to comment Share on other sites More sharing options...
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