MiSTer FPGA Forum

Hello,

is there any way to get colour picture out of NTSC cores/games on PAL only monitor by using active YC adapter and composite connection.

I set the vga_mode to svideo and ntsc_mode to 1 (PAL-60) hoping this will produce 60Hz signal with PAL encoding instead of NTSC. I also toggled NTSC/PAL switch on the YC adapter board to PAL (on a side note switching it to NTSC strangly does make any difference). Still, wherever I turn on NTSC game the image is black and white (monochrome). I have tried also with ntsc_mode set to 0 (NTSC) but stilll with no luck.

Any help with this will be much appreciated.

I didn't find a way, although sega mega drive with a multi-region mod on one of the modes showed a color picture from mister I couldn't finish it

Try to remove the yc.txt file. Otherwise it will override the PAL60 setting.

paulbnl wrote: ↑Tue Aug 15, 2023 1:38 pm

Try to remove the yc.txt file. Otherwise it will override the PAL60 setting.

Thank you. Will do. I would have never guessed this could be related.

For those interested in the topic I can confirm that trick suggested by @paulbnl can really resolve the issue. Thank you @paulbnl once again.

Althought I didn't delete the yc.txt file completly, the suggestion this file may be causing the issue conviced me the values present in it are only good for NTSC wherever refresh rate is around 60, and for PAL for _50Hz. In other words, 60Hz values are overriding the default PAL values of phase accumulator that would normally be calculated by the core in PAL60 mode.

To avoid inevitable dot crawl that would appear with default phase accumulator value when NTSC values would be removed completly, I edited yc.txt file and replaced 60Hz values with those tuned for 50Hz. The result?

• MegaDrive looks fantastic. Arguably as good as it can only be. No dot crawl, no rainbowing. Super stable image with dithering mostly gone. As getting rid of dithering was my main goal with using the composite out, I am very happy with the result.
• SNES - no issues whatsoever although I personally don't see a point of using composite out with this core having RGB input in the monitor as SNES games are not so dithering heavy as MD/PSX games;
• PS1 is hit or miss. TR1 ingame has colours and looks good with dithering noticably softened and overall looking better. However videos are B/W. There are crazy effects on PS booting logo and in general 480i video modes. But not only as FFVII in-game has that too. I will be trying to tinker some more with yc.txt to hopefully achieve the colour image in all modes.

It is just unfortunate the yc.txrt does not allow to distinguish NTSC and PAL60 values as with the next run of update_all all those customisations will be gone :/

I have the opposite problem. I'd like to use the Minimig (Amiga) core with an NTSC monitor using s-video but with 50hz.
The monitor can display 50hz, but I get no color due to color signal encoding being PAL, I assume.

I tried the approach above and changed the 50hz value to the 60hz value in the yc.txt file:

MINIMIG_49.9=42949793920

Is now changed to:

MINIMIG_49.9=34676280039

And it worked!

If you set ntsc_mode to 1 or 2, the yc.txt file wont use any of the existing values because they would use a different string for the yc.txt. So you dont need to remove the yc.txt file if you're using those other two modes.

For example, if you set NTSC_MODE to 1 and want to "tune" the core to reduce dot crawl for yc, you would have to add an "s" to the yc key, and if you set NTSC_MODE to 2 you need to add an "m".

E.g. MegaCD_59.9s=XXXXXXXXXXXX For NTSC_MODE=1 , MegaCD_49.9m=XXXXXXXXXXXX For NTSC_MODE=2

Keep in mind, if you use ntsc_mode 2 the YC module is expecting a 50 Hz image not a 60 hz image, so if you have a console still running in 60hz its not going to work.

drdysonsphere wrote: ↑Sun Sep 24, 2023 8:29 pm

I have the opposite problem. I'd like to use the Minimig (Amiga) core with an NTSC monitor using s-video but with 50hz.
The monitor can display 50hz, but I get no color due to color signal encoding being PAL, I assume.

I tried the approach above and changed the 50hz value to the 60hz value in the yc.txt file:

Code: Select all

MINIMIG_49.9=42949793920

Is now changed to:

Code: Select all

MINIMIG_49.9=34676280039

And it worked!

The value should be 42949793920, you're probably still under NTSC and thats why it works . You have to save your configuration and restart the core for it to work correctly. Its how I test it on my PVM

bricabrac wrote: ↑Mon Aug 21, 2023 9:18 pm

For those interested in the topic I can confirm that trick suggested by @paulbnl can really resolve the issue. Thank you @paulbnl once again.

Althought I didn't delete the yc.txt file completly, the suggestion this file may be causing the issue conviced me the values present in it are only good for NTSC wherever refresh rate is around 60, and for PAL for _50Hz. In other words, 60Hz values are overriding the default PAL values of phase accumulator that would normally be calculated by the core in PAL60 mode.

To avoid inevitable dot crawl that would appear with default phase accumulator value when NTSC values would be removed completly, I edited yc.txt file and replaced 60Hz values with those tuned for 50Hz. The result?

• MegaDrive looks fantastic. Arguably as good as it can only be. No dot crawl, no rainbowing. Super stable image with dithering mostly gone. As getting rid of dithering was my main goal with using the composite out, I am very happy with the result.
• SNES - no issues whatsoever although I personally don't see a point of using composite out with this core having RGB input in the monitor as SNES games are not so dithering heavy as MD/PSX games;
• PS1 is hit or miss. TR1 ingame has colours and looks good with dithering noticably softened and overall looking better. However videos are B/W. There are crazy effects on PS booting logo and in general 480i video modes. But not only as FFVII in-game has that too. I will be trying to tinker some more with yc.txt to hopefully achieve the colour image in all modes.

It is just unfortunate the yc.txrt does not allow to distinguish NTSC and PAL60 values as with the next run of update_all all those customisations will be gone :/

"yc.txt does not allow to distinguish NTSC and PAL60 values"

It does, see my post above.

MikeS1 wrote: ↑Wed Oct 11, 2023 1:59 am

If you set ntsc_mode to 1 or 2, the yc.txt file wont use any of the existing values because they would use a different string for the yc.txt. So you dont need to remove the yc.txt file if you're using those other two modes.

Oh... that was completly unexpected Great to hear this is doable. Thanks a lot for the info.