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Unstablewarpfield

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Posts posted by Unstablewarpfield

  2. Posted · Edited by Unstablewarpfield

    Ok... I couldn't resist checking up everything one final time because something in the back of my head just told me that I was missing something. I checked the voltages on all the outputs and my sync line had about 2.5 Volts on it, which to me seemed odd. After inspecting the schematics one more time for errors I noticed this:

    Error in schematics

    It appears I put R772 before R733 instead of after it. I have no idea as to how this could have happened, but it did. I decided to correct it immediately in my board files and exported another gerber to be made. I guess in a couple of weeks I will know more about whether this fixed the problem. Tbh I am a bit fed up with this mod at this point and I don't feel like ripping out the board and start fooling around with wires.

  3. Posted

    For those who still wonder... after some more careful investigation I found out I am missing the 10 nF capacitor in the audio circuit :-o.

     

    I quickly soldered one in and the problem seems to be much less now. (Still present a bit though). I might just leave it at this. It seems to be the best this mod is able to do for the console I have here :-)

  4. Posted

    Allright... I tested a scart cable with individually shielded wires and the problem still persists. It seems to be connected to the audio for sure. When I start up Spin out (where the audio is always present when you race) the jittery edges occur again, especially when I crash the car and the higher pitched sounds come in. The next thing I could do is disconnect the audio wire from the motherboard (8245 pin 27 I believe) so no audio is coming into the rgb board and see what that does to the problem. If it still occurs... I have no idea as to what could be causing this. I am running this through the xrgb mini on a samsung tv, don't know if that could have something to do with it. Could it be the audio signal coming out of the rgb board too high? Could it be the layout of components on the board itself? I don't know... we'll see more after some testing.

  5. Posted · Edited by Unstablewarpfield

    I'm jumping in here since I seem to have thesame issue, although I don't own that many games to test with. I also have a PAL unit with donkey kong not booting after the player choice, while other games (Smurph for example) work fantastic. Really blown away by the image quality btw Matthew. Running it through an internal vga-hdmi convertor on a large samsung lcd. Following this with interest.

  6. Posted · Edited by Unstablewarpfield

    Just getting back to my videopac problem a bit. My neo geo cable improved the problem a little, but the problem still persists. I took a short video of the problem to see if some of you wizzards here can identify the problem. If you look careful you'll see the edges of the pixels move as soon as some sound pops in. It looks like interference to me so I'm thinking to go with a scart cable that has individually shielded wires.

  9. Posted

    I'm about to install the F18A mod in my Colecovision, together with an internal power supply. Is it true that the -5V line is not needed anymore after installing the mod? If so... would something like this work as a power supply? It has all the right specs amp-wise on the 5V and 12V lines... Good price too and pretty easy to obtain from where I live. I ordered one from thesame line (but 5V only) for my Videopac and it works perfect :-)

     

     

  10. Posted

    Thanks Grips. I just took a look. I am not seeing the dots you describe there in your post. (playing through an xrgb mini on a samsung led tv... dunno if that has anything to do with it.)

     

    What I see is clearly linked to the sound. As soon as certain sounds pop up the edges of the pixels get a bit "wave-like" for a split second. It is not very noticable and like this it is defenately very playable. I know that my scart cable is really bad. (as in... unshielded) I might wire my din plug like my neo geo so that I can use that cable. Either that, or seperate sound RCA's.

  11. Posted · Edited by Unstablewarpfield

    Finally received my pcb design from China last weekend! So much better then my own etched board!!! Really impressed for the 10 euro's it cost me. Had to wait a couple of days for the components to arrive and soldered everything together. I kept getting some weird interference which i traced back to the two blank signals. I left the signal from leg 34 on the 8048 completely off and connected leg 9 of the pal encoder to the corresponding pad on my board and voila... it worked. Basically what you said in your topic grips03... Everything connects to the palencoder chip, with exception of the audio ofcourse.


    I do get some slight interference in the video signal that seems to be connected to the sounds playing, so I guess a seperate audio connection, or a better shielded cable is what I need. For now... I enjoy the awsome video quality that my G7000 now offers! :-D


    Videopac G7000 Pcb

    • Like 1

  13. Posted

    Hi!

     

    I was in doubt whether to ask my question in this topic or to create my own. Since mine is PAL related I decided to go with a seperate topic.

     

    I used the schematics in previously mentioned topic to create my own version of them for a PAL system. It's basically a copy and I don't think the differ very much but I am in doubt whether the inputs are connected correctly.

    Videopac G7000 RGB schematics

    I used these PAL schematics to figure out the connections.

    G7000 schematics

    What do you guys think... did I get the inputs right?

  14. Posted · Edited by Unstablewarpfield

    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 ;-)

    test 3

    test 3 close Up

    • Like 5

  15. Posted · Edited by Unstablewarpfield

    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 :-D

    • Like 1

  16. Posted · Edited by Unstablewarpfield

    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 :-)

     

    second test

     

    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 :-)

     

    test

  17. Posted · Edited by Unstablewarpfield

    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.

  18. Posted

    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 :-)

  20. Posted · Edited by Unstablewarpfield

    The PCB I designed is this.

     

    Intellivision PCB Layout

     

    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?

     

    schematic.png

  21. Posted

    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.

  23. Posted

    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!

    • Like 1

  24. Posted

    Ok... long time no reaction and everything has been on hold a bit since I bought a new house. But... finally I have space now to create my gameroom with a new Samsung tv and a Framemeister xrgb mini. When I fired up my Atari through the Framemeister's svideo port low and behold... perfect s-video signal! Problem solved. Next up... getting a second boxed 2600 and rgb mod it.

  25. Posted

    I tested about everything I could test now on this problem and still it persists. Connected the Atari to an old CRT tv and it also gave me the color problem. It's like it's shifted out of phase for some reason. Composite image is fine. I'm about to give up on this mod. Guess I'll be just using the composite video part of it then.

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