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Tim Worthington's 2600RGB Mod?


SavyIsJoshoArts

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Hi guys.

To any Atari 2600 Owners that has got Tim's 2600RGB Board kit installed. I need some help with an MINOR Issue.

Yesterday, I have successfully modded Tim Worthington's 2600RGB Mod kit + YPbPr Component Kit add-on to my original NTSC 2600 4-switch Woodgrain console. (I know it's unusual despite I live in Australia as Australia is a PAL region.)
While I am extremely happy with the YPbPr Component output with both PAL and NTSC 2600 Games hsowing the right colours.
Somehow I'm having issues to show colour on the Composite Video and S-Video Output when inserting a PAL version 2600 Games, Weirdly, This issue doesn't affect on any NTSC 2600 Games at all, only the PAL ones. :?

I attached the images of both PAL and NTSC version of River Raid in both Composite Video and YPbPr Component Outputs.

I did read on Tim's 2600 RGB Installation Guide regarding JP3. Here's the quote from his installation guide.
Quote:
JP3 Y-trap filter frequency. Open for PAL consoles, closed for NTSC consoles. The affects composite video output only.


Does that mean that if JP3 is soldered on. I lost colour when using PAL Games via Composite A/V AND S-Video if JP3 is soldered onto the board?
Help would be appreciated.

FYI, I have e-mail Tim about this issue as well, awaiting an e-mail response.

Cheers,
Josh

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I did read on Tim's 2600 RGB Installation Guide regarding JP3. Here's the quote from his installation guide.

Quote:

JP3 Y-trap filter frequency. Open for PAL consoles, closed for NTSC consoles. The affects composite video output only.

 

 

 

 

 

From what I gather from the instructions - its dependent on the console the RGB board is getting installed onto.

 

If its a PAL board - leave it Open.

 

I did my mod on a NTSC unit(jumped/closed) and had all the video outputs installed. I was able to test pal and ntsc with a PVM and a couple of tvs.

 

Are you using a pal and a NTSC carts to test? The Harmony cart will work with both too.

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Are you using a pal and a NTSC carts to test? The Harmony cart will work with both too.

G'day H454,

 

Sadly I do not have a Harmony Cart on my hands for this system. I have been testing it with both PAL and NTSC carts.

 

As it was explained YPbPr Component shows colours on both PAL and NTSC without any hassil.

Composite Video and S-Video however shows NTSC colours fine, but not PAL colours.

 

I looked on the RGB board and can't see what the issue is, I could only guess it may be my TV since I tested it on a Sony Bravia HDTV.

Cbeers.

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Are you using a PAL 2600 and do you have JP3 soldered closed?

I already stated on my original post that the console is ORIGINALLY a NTSC 2600 4-Switch Woodgrain console. Yes JP3 is closed.

 

Yesterday, I have successfully modded Tim Worthington's 2600RGB Mod kit + YPbPr Component Kit add-on to my original NTSC 2600 4-switch Woodgrain console. (I know it's unusual despite I live in Australia as Australia is a PAL region.)

 

Edited by activision man
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As you may already know RGB and/or YPbPr signaling does not carry NTSC/PAL info at all, it's simply number of lines and frequency and that's it as there's no color modulation per se, and that explains why you can play both PAL and NTSC games via that kind of connection in colors for as long as the TV can latch (some old TVs even with Scart support would not latch on a 60Hz signal but anything past 1990 should have no issue, it is also likely that no NTSC TV would latch on a 50Hz signal until much recently due to 576i50 being a digital std).

 

Wrt to Composite/SVideo instead PAL/NTSC color encoding still matters. In specific PAL TVs are usualy able to also resolve what's called PAL60 (that is really a PAL-ish signal at 60Hz barrying the number of lines and that would be a PAL console forced to play at 60Hz) while almost no NTSC TV was ever able to resolve NTSC50 (the equivalent to PAL60 but in NTSC land).

Note not all consoles can generate 525/60Hz signals (it depends on their circuitry) so some get some hybrid 625/60Hz but I digress.

 

You can see colors in your NTSC3.58 mode (your TV identifies it) as it is std NTSC via Composite/SVideo and your TV seems to be multistd and have no issue with it but for "PAL" it goes B&W because what you get is really "PAL 3.58" which does not exist (a 625 lines 60Hz signal with chroma in the NTSC band of 3.58) ... I presume that is what your 2600 is actually spitting out at that point. Very close to PAL as you can tell but with no color.

 

Tim's board uses a BH7236AF to reencode the Video/Svideo signal and that chip requires a proper color subcarrier and NTSC/PAL switch which is what J3 does imho (unsure where it gets the actual subcarrier frequency 4.43 for PAL and 3.58 for NTSC).

Here's the link to the encoder https://media.digikey.com/pdf/Data%20Sheets/Rohm%20PDFs/BH7236AF,%20BH7240AKV.pdf

 

In short as for many other consoles video mods I don't think you can get PAL and NTSC support output in color at the same time via Composite/SVideo by their nature.

The only console I am aware of that can actually do it and via SW at that is the Commodore CD32 because you can modify via SW at boot both the color subcarrier frequency AND the PAL/NTSC color encoder mode, there may be others mind you I am just not aware of any, and even for the CD32 you really need a TV that can accept both (your TV seems to be able to with a proper PAL and NTSC signal).

 

Bottom line play via RGB or YPbPr and you're golden if you want to be free to switch PAL/NTSC games and enjoy colors ... I believe if you had a PAL console by virtue of PAL60 widespread support you'd be better off as color PAL60 is/was an actual thing, not sure the VCS supported it but it may just have worked out.

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Tim's board uses a BH7236AF to reencode the Video/Svideo signal and that chip requires a proper color subcarrier and NTSC/PAL switch which is what J3 does imho (unsure where it gets the actual subcarrier frequency 4.43 for PAL and 3.58 for NTSC).

Here's the link to the encoder https://media.digikey.com/pdf/Data%20Sheets/Rohm%20PDFs/BH7236AF,%20BH7240AKV.pdf

 

In short as for many other consoles video mods I don't think you can get PAL and NTSC support output in color at the same time via Composite/SVideo by their nature.

The only console I am aware of that can actually do it and via SW at that is the Commodore CD32 because you can modify via SW at boot both the color subcarrier frequency AND the PAL/NTSC color encoder mode, there may be others mind you I am just not aware of any, and even for the CD32 you really need a TV that can accept both (your TV seems to be able to with a proper PAL and NTSC signal).

 

Bottom line play via RGB or YPbPr and you're golden if you want to be free to switch PAL/NTSC games and enjoy colors ... I believe if you had a PAL console by virtue of PAL60 widespread support you'd be better off as color PAL60 is/was an actual thing, not sure the VCS supported it but it may just have worked out.

Hi phoenixdownita.

 

I cannot believe I didn't think the crystal oscillators frequencies do play a big role on this. *facepalms* And here it had me thinking it was a fault on the S-Video / Composite Video lines.

Seriously mate, this has answers more than what I expected. I never thought to think this was the reason for it due to the frequency of the oscillators. Big kudos for you mata and thank you heaps.

 

On the very bright side, I did originally wanted this mod to get RGB and YPbPr outputs, Only had me concerned incase something went wrong with the TV and the second hand one I had didn't have YPbPr i'd had to be stuck with S-Video and Composite Video

 

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