Atari 2600/5200/7800 RGB or True Digital HDMI Mods?

Discussion in 'Modding and Hacking - Consoles and Electronics' started by MonkeyBoyJoey, Mar 3, 2015.

  1. MonkeyBoyJoey

    MonkeyBoyJoey 70's Robot Anime GEPPY-X (PS1) Fanatic

    Joined:
    Mar 1, 2015
    Messages:
    1,742
    Likes Received:
    318
    Hello everyone. This is something that has been on my mind for a while. Can the Atari 2600/5200/7800 consoles be modified for RGB? I've heard whispers around the web but no concrete answers. I would love to play Asteroids via RGB SCART! Is a true digital HDMI mod possible too, like the recent NESHD mod? Any help would be highly appreciated! Also, I should mention that I'm new at the inner workings of electronics so please forgive me if I don't understand some things.
     
  2. wilykat

    wilykat Site Supporter 2013

    Joined:
    Mar 25, 2012
    Messages:
    991
    Likes Received:
    45
    Those game consoles originally can only do composite and with some effort, S-Video. You will need to do a chip replacement to get better signal out of those Atari systems. The video chips were never designed to have high quality output.

    Your best bet is to find someone who can hack the console and build a custom interface like NESRGB board to generate proper RGB, HDMI, or component.

    Atari 2600 will be a bitch to build RGB board because it doesn't use video RAM at all. The video is drawn on the fly as the game runs, I hear it takes an average of 80% of CPU power just to maintain video image while leaving small part to actually run game code.
     
  3. MonkeyBoyJoey

    MonkeyBoyJoey 70's Robot Anime GEPPY-X (PS1) Fanatic

    Joined:
    Mar 1, 2015
    Messages:
    1,742
    Likes Received:
    318
    Is there someone on here that can do that? Does the 2600 really do that? What was Atari thinking during development... Would that also apply to the 5200 (with VCS adapter) and the 7800 running 2600 games?
     
  4. wilykat

    wilykat Site Supporter 2013

    Joined:
    Mar 25, 2012
    Messages:
    991
    Likes Received:
    45
    Atari 2600 were designed and built in the late 1970's and the 5200/7800 in early to mid 80's. Back then most people only had antenna for their TV and TV almost always had only RF input, no composite or anything. VCR didn't come into wide use until later and TV with better video input also didn't come out until later. So don't blame Atari for limiting their consoles to feeble looking video quality, blame customers for not demanding a TV with RGB input.

    Nintendo NES and Sega Master Systems were the first to offer composite as standard. SNES, TG-16, and Genesis both could do RGB and that was toward mid 1990's.

    Component and HDMI weren't around for many more years, long after Atari went bust and quit making new consoles.


    Atari 5200 with VCS adapter and Atari 7800 still used the same 2600 video chip so it's still limited as well. I don't know of anyone who has completely rebuilt a replica of 2600 video chip and made a modern version that can output RGB or component. Intellivision also had the same limitation and it was only just last year that someone started making an RGB chip for them.
     
    Last edited: Mar 3, 2015
  5. Unseen

    Unseen Spirited Member

    Joined:
    Sep 1, 2014
    Messages:
    126
    Likes Received:
    17
    It does. There is no frame buffer, the CPU is constantly reprogramming the graphics chip to prepare the graphics to be displayed on the next line. There is a book "Racing the Beam" which as far as I know describes the process and how it has influenced the games that were made for the 2600, but I haven't read it.

    Their main concern was to build a games system for games similar to Pong and Combat, but with a microprocessor and games on a cartridge to allow more flexibility. Of course it had to be affordable, so a full frame buffer was not an option.
     
  6. MonkeyBoyJoey

    MonkeyBoyJoey 70's Robot Anime GEPPY-X (PS1) Fanatic

    Joined:
    Mar 1, 2015
    Messages:
    1,742
    Likes Received:
    318
    Oh ok. I heard of some RCA TVs here in the USA that had RGB SCART inputs, but they were labeled as "EIA Multiport - Stereo" and I think it was limited to the RCA Dimensia line. I read online that the video chips in the Sega Mark III and the ColecoVision output Component video natively but requires modification to use it.

    I didn't see your post Unseen (no pun intended) when I made my last post. Is someone up to the challenge of making an RGB and possibly true digital HDMI mod? I would definitely get one if it is done, but I would need to get a 5200 and another 7800 because I promised my mother I wouldn't take a screwdriver anywhere near her 7800. It was my first system.
     
    Last edited by a moderator: Mar 7, 2015
  7. wilykat

    wilykat Site Supporter 2013

    Joined:
    Mar 25, 2012
    Messages:
    991
    Likes Received:
    45
    I've asked that in atariage forum, there are hard core 2600 and 7800 experts there that may be able to figure out if the video chip can be upgraded or replaced with one that provides RGB.

    I believe 5200 adapter can take 2600 RGB upgrade if one exists but it'd have to have separate connector as the video signal is normally passed through 5200 connector to 5200 video circuit and reworking that to make it do RGB for both 5200 and the 2600 adapter would be a rather large task. 5200 board itself is huge and the only thing that dwarfs the original XBox.
     
  8. MonkeyBoyJoey

    MonkeyBoyJoey 70's Robot Anime GEPPY-X (PS1) Fanatic

    Joined:
    Mar 1, 2015
    Messages:
    1,742
    Likes Received:
    318
    So should I go there and ask if an RGB or true digital HDMI mod can be designed?

    How much smaller is the 2 controller port model? Speaking of Xbox, my cousin gave me his broken original Xbox. I should probably get that fixed...
     
  9. Greg2600

    Greg2600 Resolute Member

    Joined:
    Jun 23, 2010
    Messages:
    937
    Likes Received:
    112
    You can get S-Video from those systems, honestly that's as far as I'd go. The expense isn't worth it.
     
  10. Mamejay

    Mamejay Robust Member

    Joined:
    Sep 20, 2010
    Messages:
    258
    Likes Received:
    1
    I have a French Atari 7800 that is Factory RGB. You can look around for one of those. Only problem is that they use PAL chips so NTSC game colour will be off.
     
  11. MonkeyBoyJoey

    MonkeyBoyJoey 70's Robot Anime GEPPY-X (PS1) Fanatic

    Joined:
    Mar 1, 2015
    Messages:
    1,742
    Likes Received:
    318
    I've heard of these. How much do they go for normally? Do they play NTSC games at 50Hz or 60Hz and is there any way to fix the color issue?
     
  12. wilykat

    wilykat Site Supporter 2013

    Joined:
    Mar 25, 2012
    Messages:
    991
    Likes Received:
    45
    I've already asked. No volunteer to reinvent the video chip yet.

    2 controller board is the same size as 4 controller board. Just fewer parts.
     
  13. Unseen

    Unseen Spirited Member

    Joined:
    Sep 1, 2014
    Messages:
    126
    Likes Received:
    17
    I wouldn't be surprised if it just has an additional board that decodes the PAL composite signal to RGB.
     
  14. MonkeyBoyJoey

    MonkeyBoyJoey 70's Robot Anime GEPPY-X (PS1) Fanatic

    Joined:
    Mar 1, 2015
    Messages:
    1,742
    Likes Received:
    318
    Oh ok. Hopefully someone will one day.

    If that ends up being the case, could it be reversed engineered like what you did to the GameCube component cable DAC?
     
  15. Unseen

    Unseen Spirited Member

    Joined:
    Sep 1, 2014
    Messages:
    126
    Likes Received:
    17
    Why would you want to reverse engineer a board from the 1980s when you can just search the net to find circuits that can perform the same function, preferably with parts that are newer and thus easier to get?
     
  16. MonkeyBoyJoey

    MonkeyBoyJoey 70's Robot Anime GEPPY-X (PS1) Fanatic

    Joined:
    Mar 1, 2015
    Messages:
    1,742
    Likes Received:
    318
    Oh. What can I use to do this?
     
  17. Unseen

    Unseen Spirited Member

    Joined:
    Sep 1, 2014
    Messages:
    126
    Likes Received:
    17
    The easiest way would be to plug the composite video signal from the console (requires modding) to a composite video input of your TV/monitor and use the PAL/NTSC-to-RGB decoder that is already built in.

    Or you could search for "pal to rgb decoder" which should result in lots of hits for datasheets of various chips that were usually designed to be integrated into a TV for just this job. The datasheets usually have an example application circuit that you could adapt for this purpose. Alternatively, there is a small number of projects on the net that have done that part of the work already, for example this one.
     
  18. ApolloBoy

    ApolloBoy Gutsy Member

    Joined:
    Sep 22, 2011
    Messages:
    425
    Likes Received:
    0
    That is exactly what it does for RGB.
     
  19. Wolf_

    Wolf_ Rising Member

    Joined:
    Jun 30, 2016
    Messages:
    70
    Likes Received:
    5
    Sorry to necro but I Just thought I'd update this topic as it is one of the first results in my search engine when searching for 5200 rgb mods.

    Atari 2600 - Has S-video and rgb mods available here: https://store.retrofixes.com/collec...e-service-installation-4-6-switch-or-jr-model

    Atari 5200 - Rgb mod is in final steps of development (13 mins 12 seconds-ish in)
    https://atariage.com/forums/topic/258702-new-development-gtia-in-cpld/

    Atari 7800 - French version does output scart without a mod, however it is via a s-video to scart adapter so the quality will not be better than native s-video out. S-video mod board is available here: https://atariage.com/forums/topic/236273-new-7800-s-video-board-available/
     

Share This Page