OSSC – Losing Sync?

[Aragorn]

Hi guys,

I bought an OSSC last year, played with it a little and not really got on too well with it. Dug it back out and hoping to get it working.

I’ve got two consoles primarily to use it with, a Sega Mega Drive, and a Sony PS1. Also got an N64 but its not capable of RGB yet so not done anything with that.

With the megadrive, you can fire the console up, and it works, of a fashion, but randomly and frequently (multiple times a minute) the OSSC loses sync (red LED comes on and screen goes blank) and then returns. This makes gameplay almost impossible.

Switching over to the cheapy ebay spec RGB Scart to HDMI converter, works fine with no cutting out. My particular megadrive is a French model which comes from the factory with only RGB output.

Then, with the PS1, it works a bit better, but similar effect occurs. I’ve not tested the PS1 as much to figure out specifics. But it seemed less random and more repeatable on the PS1, eg a particular area of gameplay or opening a menu or something would trigger it. I need to have more of a look at the PS1 issues.

I tried the OSSC with a 640×480 VGA signal from a PC, and it worked fine.

Could this just be a bad scart cable?

[NoTikEnoShirtE]

Try changing the Sync Menu options on the OSSC. Un-modded Consoles that output RGB like Mega Drive might benefit might need to be set to a specific LPF rate (Low Pass Filter.)

Press menu on the OSSC Remote, press Up to Scroll the different Menus until you find Sync Opt. Press OK, then press Up or Down until you hit ‘LPF.’ Should be at 10 by default. Try all the different settings to see if it improves.

[Harrumph]

French Mega Drive doesn’t work with the “Adapteur RVB” that it came with originally. Seems you need a cable wired for c-sync instead. Check the thread below for more info:

[Help] No image but Sync with SEGA Megadrive and MultiMega

[Aragorn]

I jumpered the CSync pin to Composite pin inside the megadrive to fix that issue, otherwise no picture at all.

[Harrumph]

Then it’s probably your cable.

[Aragorn]

Thanks for the help thus far. I’ll get a better cable ordered up and see how it goes with the Megadrive.

I’ve finally dug the PS1 out and got it hooked up. This ones using a decent cable from retrogamingcables.

This one doesnt have the sync issues, at least with the game i tried today. However with the PS1, everything on screen sort of jiggles around. The whole frame seems to constantly jump left and right a pixel or two, leaving everything a bit blurry and horrible.

Any ideas with that?

Again, swap the OSSC out for the crappy ebay converter and the problem goes away.

[BuckoA51]

Which game are you playing when you see that?

[Aragorn]

I actually just bumped another thread which perfectly describes the wobble and the guy manages to video it too.

0.82a: OSSC wobbles the image on my PSIO-modded PSX on certain games

The game in this instance was “Bob the Builder” a kids game that I had to hand. As per the other thread, switching source and back fixes the wobble.

I tried crash 2 last night and it went directly to 49.76hz and didn’t exhibit the wobble

[BuckoA51]

Ah yes bug with the digitiser, Framemeister exhibits erratic behaviour going 240p_>288p too.

[Author]

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