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MiSTer-devel / MegaDrive_MiSTer

Sega Megadrive for MiSTer
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Analog video elevated blacks and green tint #28

Closed leckel1996 closed 8 months ago

leckel1996 commented 8 months ago

Using analog out there is a green tint and the black levels are elevated compared to the hdmi output.

birdybro commented 8 months ago

What kind of connection are you using for analog?

leckel1996 commented 8 months ago

DE-15 output to RGBHV cable and using RGBS output from the mister. Every other core I’ve tested looks correct as far as black levels and color. I can add pictures if it’s helpful.

birdybro commented 8 months ago

Hrmm maybe the core is sending out some green instead of black during vblank...

sorgelig commented 8 months ago

strange that no other users complained yet. May be it's something specific between particular TV and this core

leckel1996 commented 8 months ago

I will say I’m probably not the typical user as far as my background and what I do for my job. IMG_3221 IMG_3220

Here are some not so great pictures of the 240p test suite on the genesis core and nuked md core.

birdybro commented 8 months ago

What Make/Model of CRT is it? I agree it's probably something that only affects certain CRT's. The TMNT arcade core had a tangentially similar issue early on that was related to specific different CRT's.

leckel1996 commented 8 months ago

JVC BM-H1900SU

MP2E commented 8 months ago

Strange, looks ok on my Sony PVM-1953MD. Though I’m also using direct video APC_0055

leckel1996 commented 8 months ago

HDMI output looks fine so I wouldn’t expect direct video to have the same issue

leckel1996 commented 8 months ago

I’m going to get a vga cable and connect the output to my ossc to see if I see the same thing.

birdybro commented 8 months ago

Have you already tried changing the outcome by changing these options in your MiSTer.ini?

https://github.com/MiSTer-devel/Main_MiSTer/blob/master/MiSTer.ini#L5-L6 https://github.com/MiSTer-devel/Main_MiSTer/blob/master/MiSTer.ini#L33

Maybe vga_sog needs to be turned on (if it's actually RGsB instead of RGBS). Here's a table by Porkchop Express that should give you the description:

https://mister-devel.github.io/MkDocs_MiSTer/advanced/crttable/

From the user manual for your CRT:

image

Are you using a cable with the external sync breakout?

BM-H1900SU-1.pdf

leckel1996 commented 8 months ago

The sync on green switch on the analog io board seemed to fix it. For whatever reason its effect was a lot more drastic with this core than the other cores. Thanks for solving my problem even though it had nothing to do with the core.

birdybro commented 8 months ago

Sweet!