modding an Amiga CD32 for RGB

Discussion in 'General Gaming' started by Missyrelm, Mar 28, 2008.

  1. Missyrelm

    Missyrelm Active Member

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    Hi,

    My wife and I are trying to find someone to mod an Amiga CD32 to output RGB and are looking for suggestions as to who can/will do it.

    We am getting ready to buy an Amiga CD32, but our TV is NTSC, and only accepts 60hz signals. So, we are hoping to get around that by modding the CD32 to output RGB instead.

    Our Samsung TV’s specs say RGB input, and on the back it says “PC inputâ€, which I am assuming is the RGB.

    My understanding is that as far as mods go, this is a pretty easy one, I just don’t know how to solder or read schematics, and don’t want to practice on a classic console.

    We have a good history of buying modded consoles and mods of consoles that I provide…
    I can provide a list of people I’ve done business with, and also we have an excellent rating on ebay as buyers.

    My understanding is that the mod is “just†taking an amiga rgb cable, cutting the db 23, then locate the RGB and video at the TP9 test port near the fmv connector,
    where there are pins where you can solder the cable.

    Thanks to anyone who can help!

    Here is the schematics from the Amiga CD32 FAQ
    (they come out kinda messed up on this forum post so I have the link here too...

    http://www.faqs.org/faqs/amiga/CD32-FAQ/part2/

    CD32 RGB signals...

    The RGB signals are available from a test port, TP9...

    | | | <--- Kickstart ROM .-. Desc Equiv pin #s
    | | | |o|
    | | | |o|
    | `--' .----. <--- Akiko |o|
    | | | |o| HSync 159
    | | | : <--- TP9 |o| VSync 160
    | `----' : |o| Red 163 and 164
    | .. :O.--. |o| Green 165 and 166
    `-------'`----------' | |o| Blue 167 and 168
    ^ ^ `------- |o| CSync 157
    | | |o| Ground 161 and 162
    Expansion port Pin 182 `-'

    The RGB signals come from the D/A conversion unit and lead directly
    to the expansion port. These signals are, however, not amplified. In
    addition they are weakened by the S-Video output unit.

    As a result I (aim to) insert a 47 Ohm resistor to each colour signal
    connection. You may also reduce the load by interrupting the signal
    supply to the S-Video unit. Set pin 174 of the expansion port to GND
    to achieve that (174 --> u36 (4066) signal switches).

    The sync signals connected to the expansion port are unbuffered. As
    a result you may re-synchronize your Amiga by an external tact
    source. You schould at least buffer the CSync line; there is no
    external synchronisation possible on this pin.

    Hint: make use of an XOR gate chip. You may negate certain sync
    line(s) to adapt your Amiga to (old? :-( ) multiscan-monitors (the
    A4000 monitor adapter box will do the same; without the possibility
    of selected negation).

    Written by Klaus Hegemann, posted as part of 'CD32 expansion port
    info' by Anders Stenkvist in comp.sys.amiga.hardware, forwarded by
    Michael King.
     
    Last edited: Mar 28, 2008
  2. Jamtex

    Jamtex Adult Orientated Mahjong Connoisseur

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    PC Input could also just mean VGA only (probably true if it does only have a 15 Pin HD D-Socket), I would check the manual again as it might not display any picture if it is an LCD or Plasma screen and doesn't like 15Khz signals. Also as a number of CD32 games use 50Hz PAL modes, if your TV doesn't do 50hz modes then although you could force the game to use 60hz you will lose a large part of the bottom of the screen. I suggest you just plug it in via Composite video and see if you get a stable picture (even in black and white).

    You do need to amplify the signals though, but if I remember a N64 RGB circuit amplifer works well.
     
  3. retro

    retro Resigned from mod duty 15 March 2018

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    Hmm, not sure why this is in the rare section! I would have gone with a more general forum. Oh, and if you want help, fill out your profile info or state where in the World you are! Some members could be put off by having to ship around the World!

    Just because you use RGB, doesn't mean it'll not be 50Hz. You still need to give a sync, and the console, if PAL, will output a 50Hz sync. You could in theory force it to output 60Hz (not studied a CD32 in great schematic detail, so I don't know whether that would involve component swapping), but you may indeed run into problems as mentioned.

    Interesting choice of text colour, by the way! Brown on black, wouldn't have thought it would work!! ;-)
     
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