Results 1 to 3 of 3

Thread: RGB to VGA cable and using with GBS8220

  1. #1
    rabidgerry's Avatar
    Join Date
    Jul 2019
    Country
    Ireland
    Region:
    Northern Ireland
    Age
    37
    Posts
    4
    Feedback
    0

    Default RGB to VGA cable and using with GBS8220

    Hi all, first time posting here so hopefully I find the answers I'm looking for. Also apologies for bringing up old topics yet again!

    So I made a VGA to RGB cable myself and I use it with my GBS8220 board for upscaling. However I have on another forum and on another thread been told to change things on said cable, but upon asking about these details I never got any answers back so I am just wondering if anyone here can help or tell what I'm doing wrong?

    So one of the suggestions was this

    Can you connect a few more grounds? There should be three grounds for the RGB signals and another sync ground (VGA pin 10)

    Another was

    If you separate the digital sync signals return from the video, you should get a cleaner image.

    Here is my home made cable





    Also I shall add that my original issue was I was having weird thick vertical lines in the display. I initially though it was because I was plugging my Amiga 15khz output into the GBS8220 VGA input which is 30.5-32.5K but what actually was the issue was I had a ground going to pin 15 on the RGB connector and not going to pin 16. When I switched this about the thick lines had gone and I was getting the same quality of display I was getting when I originally used the 8 pin header on the board.

    Now I know the GBS board can take an Amiga 15khz signal however the input on the GBS board is supposed to only take 30.5-32.5K input so I was wondering why when I connect my Amiga to this input it still works for me?

    Also see below a premade VGA to RGB cable I recently bought on ebay. It's wired differently to mine, can anyone explain why this is? I have always read to use the GBS board with Amiga to use the c sync and use a 680ohm resistor to reduce some voltage going to the board. However this cable has the vsync and hsync in use, is I was to use this cable should I disconnect those and just use the csync?

    An one last thing? Why is the ground wire on this premade VGA going to pin 13 and then connected via a white wire to the other ground pins on the RGB connector (pins 16 to 20).





    Hopefully I can get some info, thankyou in advance anyone who cares to answer and explain. I'm not super technical as you may have guessed

  2. #2
    rabidgerry's Avatar
    Join Date
    Jul 2019
    Country
    Ireland
    Region:
    Northern Ireland
    Age
    37
    Posts
    4
    Feedback
    0

    Default

    I guess no one knows

  3. #3
    Amibayer! timtheloon's Avatar
    Join Date
    Apr 2015
    Country
    United Kingdom, England
    Region:
    Hampshire
    Posts
    2,686
    Feedback
    155 (100%)

    Default

    Hi rabidgerry

    I think Amibay's resident "Cable Guy" a.mi.goun makes these, maybe if you PM him, he could help you out with the Answers you are looking for. Worth a try
    Last edited by timtheloon; 25th May 2020 at 17:54.
    Got too many Amigas, Think I gotta problem


Similar Threads

  1. For Sale GBS8220
    By Kulamario123 in forum Amiga
    Replies: 4
    Last Post: 4th July 2019, 23:19
  2. For Sale Scandoubler GBS8220
    By Kulamario123 in forum Amiga
    Replies: 0
    Last Post: 28th March 2019, 21:19
  3. Replies: 14
    Last Post: 21st October 2015, 10:36
  4. GBS8220 and Retro consoles ?
    By dougal in forum AmiOracle
    Replies: 1
    Last Post: 23rd April 2014, 12:22
  5. Sold Gbs8220 v3.0
    By Chinners in forum Sales Archive
    Replies: 4
    Last Post: 3rd November 2011, 08:52

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •