OSSC sync issues with PAL PSOne (“slim”)

[GlacialSpoon]

Hi all, hoping to get some advice.
I’ve been using my OSSC (0.9a) with a PAL Playstation 1, via a CSYNC RGB SCART from RGC for years without issue. I recently acquired a PAL PsOne (the little PS1) after my original PS1 gained a minor fault, but I’m finding getting a stable sync with the OSSC and PsOne to be difficult.

I managed to dial in some stability at the lower resolution (226p is it?) but 314p outputs from the Playstation seem to break everything. I’ve noted my Vth value is notably higher than most recommend (around 280mv). I followed multiple sources of advice around the tolerances and PLL coasting and whatnot but can’t seem to get it right. I’ve also heard that the CSYNC cable might not be the best choice.

All suggestions/questions welcome. Just looking to get playing on actual hardware with modern TVs again. Thanks!

[Kekstier]

Hello,

Use a simple SCART-to-VGA Adapter! Because your PS-One has indeed only composite output, you can use for example this:

RetroUpgrades SCART2VGA Adapter (active) or cheeper like e.g. from DeLock, etc. (passive) …

Maybe you need also a RCA-to-SCART Adapter, a simple from DeLock, Hama or so is enough!

Then you can via VGA in your OSSC and its configuration and specification are more convenient… i have thought the technical specification of the PS-One is to special for the OSSC (and maybe also die ossc pro!)…

 

Good Luck
Sebastian

• This reply was modified 1 day, 11 hours ago by Kekstier.
• This reply was modified 1 day, 11 hours ago by Kekstier.

[GlacialSpoon]

Hi Kekstier, thanks for the reply.
Using VGA is an interesting approach, one I hadn’t thought of. The PSOne does have RGB output though, not just composite. I’d hope that the right SCART setup would suffice.

Interesting note that the PSOne might be “too special”. Is this a common thing for PSOne vs PS1? Would a VGA converter be any better at dealing with an awkward spec?

[BuckoA51]

On the OSSC classic, the VGA input does not have the low pass filter, so it’s not recommended for SCART sources which typically benefit from this.

First of all, if you let the console just go to the memory card screen (no disc inserted) is the image stable then?

[GlacialSpoon]

Hi BuckoA51,

Yes, the BIOS/memory card/cd player screens are stable.

To be more specific, Formula 1 97’s pre-race screens are the worst offender here. The OSSC displays “314p” during these screens. During gameplay, a lower resolution output is used and the sync is much better, but still has the occasional dropout. I have had these screens working perfectly on the PS1 (and PsOne  when I first tried it) without any tuning but now OSSC defaults or my tunes do not work. The image syncs intermittently and when visible shows extreme horizontal wobble and patches of discolouration.

[BuckoA51]

314p doubles to a troublesome 628 line 50hz image which trips up a lot of TVs and monitors, but if your other console works then it seems unlikely to be that.

[marqs]

I’ve seen one such PSOne that had curling with a 100Hz digital-enhanced CRT it was connected to so maybe the sync signal is different to earlier models. I should have a chance to try that unit with OSSC within the next few weeks to see if it results to similar sync issues and if there’s a simple fix (usually these kind of cases have got solved via increase of coast).

[GlacialSpoon]

I gave Formula 1 97 another go earlier. I may have been wrong before as the OSSC was showing 314p the whole time. The issues were in the same places though. Gameplay was fairly compromised on the Montreal track due to dropouts. The pit lane entry seems to reliably cause a problem for some reason.

Coasting is currently set to 4 lines but I haven’t noticed much difference with any value.

[Author]

Posts