Pal DC - Garbled image with Jojo and SFA3

[DeMeester]

I'm having some problems running my japanese version of SFZ3 (JoJo's Bizarre Adventure as well) on my pal machine. I think it has something to do with the pal-60 Hz mode but I'm not sure.
On my unmodified japanese DC the games run without problems. My modified DC has a Dreamshell boot loader bios and a cf-reader installed.

I made a copy of the gd-rom disc and downloaded a pal copy of the game to test.
When I start the jp game the music can be heard but the image is all garbled. When I run the pal copy in 60Hz the same thing happens. If I run it in 50Hz everything boots up normally.

My Dreamcast is connected to my tv (samsung 40ju7000) via a Marantz SR5011 by using a s-video cable via xrgb mini/hdmi out.
Is there a way to patch my japanese gd-rom image so it works on my modded DC?

I'm not experiencing this issue when I switch (my modded dc has 2 custom bioses) to the japanese_cake 1.032 bios. JC 1.031 has the same issue. The only difference between the 1.031 and 1.032 is the region patch and force 60Hz I think.

Thanks for any advice/help.

[DeMeester]

I think it's related to the way in which a Dreamcast handles region info. I just read on another forum that a PAL dreamcast always boots any region game to pal50 or pal60. I'll have to further investigate by checking a couple of us/jp games when I boot them what my tv tells me about resolution and ntsc or pal mode.

[DeMeester]

My tv doesn't show me anything about regional info. Can't remember ever seeing a tv showing that to be honest.

Does anyone know a way to patch the dreamshell bootloader bios so it behaves the same as the japanese_cake bios 1.032?

Maybe it's easier to patch SFZ3 to force a specific region and Hz mode. Could some more knowledgable people give me any pointers?

Thanks in advance.

[whschimmel]

Maybe this will be usefull for you:
Region / Frequency Patcher