Sync issues with Sega Saturn & display moving up/dn by 1x line every few secs

mzryz commented 2 years ago

Hi all,

Firstly thank you to everyone behind this project and all their hard work. I have a couple of issues I am hoping to get some advice with.

My system GBS-8200 (v4 on pcb, black buttons) with All recommended mods from the wiki, using latest version of GBS-Control (installed 04/03/21) My GBS also has the clockgen installed. Input to the GBS is coming through SCART via an adaptor I purchased on ebay: https://www.ebay.co.uk/itm/174167761444

Issue 1: Sync issues with Sega Saturn

This only seems to happen on the Saturn. My Saturn has a pal/ntsc switch and swapping between 50/60hz doesn't seem to change the issue. I have made a video of the problem because it is much easier than explaining, the url on google drive: https://drive.google.com/file/d/1JPdLZcOqUuSNeSquPhZcu4wNY1q0CdUk/view?usp=sharing

As you can see, it loses sync momentarily on the initial saturn boot screen, then it seems to lose sync in some video playback sections of a game, these may be interlaced modes I am not sure. The game shown is Castlevania Sotn.

Issue 2: Screen moving up/down by 1x line every few seconds (All consoles)

The video then zooms towards the screen to show the screen moving up/down by 1x line every few seconds. This issue is the same across all consoles I have, Megadrive/Nes etc. So not Saturn Specific.

What I have tried

I have made sure all my software is up to date
I have made sure all recommended hardware mods are performed
I have tested on different output resolutions
I have tested with scanlines on/off same result
I have tested with complete factory defaults

mzryz commented 2 years ago

Diagnostic information:

`Activity detected, input: RGB VSync: present HSync: present (with CSync) RGB/HV (CSync) RGB/HV upscale mode matched preset override > 1280x1024 ADC offset: R:43 G:44 B:43

preset applied: 1280x1024 for scaling RGB (CSync) Note: scaling RGB is still in development

(H-PLL) rate: 976 state (no change): 1 HTotal Adjust: -6, source Hz: 49.920, output Hz: 49.940 ``

mzryz commented 2 years ago

My Saturn is using a sync on luma cable, so I don't think this should be detected as Csync? Does the GBS support sync on luma?

mzryz commented 2 years ago

Okay I've read: https://github.com/ramapcsx2/gbs-control/wiki/Inputs%3A-SCART-adapter%2C-optional-sync-stripper

So sync on luma is probably the issue and I should probably just get a Csync scart cable and see if it fixes it. I'll keep the issue open for now.

Thanks 👍 for all the help so far guys.

mzryz commented 2 years ago

Replacing with a composite sync cable fixed the issue.

ramapcsx2 / gbs-control