Taito F3 Arcade Board Won't Sync With OSSC; Works with Framemeister

[vasilas432]

Great! I am confident you will fix it. My F3 boards (2 of them) didn’t have picture all though, even with maximum v sync.
If you fix it then you can try a Capcom board with OSSC taking signal from a PVM line out.

Thank you Marqs

[ShootTheCore]

Exciting news indeed! Thank you for looking into it marqs.

[marqs]

I checked the sync signal via scope and didn’t notice anything extraordinary besides F3 using odd-odd field signaling like many other Taito boards. As the digitizer chip in OSSC has trouble accepting such signaling via analog sync inputs, I hooked up RGB+csync from Supergun to AV3 (csync -> VGA hsync pin). Then I switched to AV3 RGBS mode and set H-PLL pre and post coast to 4, after which OSSC happily locked to the signal.

I wonder if there are some differences between boards (or even games) as I didn’t manage to get my Framemeister to work well with F3. I had to disable framelock to get it to sync at all, but even then vertical jitter was bad enough to make any games unplayable. I recall FM getting along with odd-odd field signals with some caveats.

[ShootTheCore]

Huh, that’s really interesting Marqs. I’m surprised-I’ve tried three different Taito F3 boards on my setup with identical results-no sync with the OSSC, perfect effortless sync with the Framemeister. Maybe the SuperGun or SCART cable I’m using is a factor. Did you find that a sync stripper was necessary for an OSSC sync?

[vasilas432]

Hi marqs,
Can you please tell the pinout of a vga male connector?
If I understand correctly we need a cable which will be female scart—> male vga.

[marqs]

Yes, it’s just a passthru cable with following pinout (not including grounds which are available on many pins)

    SCART (F)                   VGA (M)
R     pin 15                      pin 1
G     pin 11                      pin 2
B     pin 7                       pin 3
S     pin 20                      pin 13

[ShootTheCore]

I’ll see if I can land one of those SCART to VGA cables and try the Taito F3 again. Fingers crossed…

[vasilas432]

I will try to just swap sync on the Extron input and output. OSSC may play RGBS via scart?

[marqs]

@vasilas432: I didn’t understand your question. If you can get RGB + (TTL-level) csync and feed it to VGA input on OSSC, then you should be fine.

[vasilas432]

I am looking for a vga cable to cut and mod it with a scart. I think I can do it. I will update when ready
Thanks marqs

[darkstrider2]

@vasilas432 I had a extra 5-BNC to VGA cable to put Extron-out into the OSSC. If you were testing for sync drops, I still got sync drops.

[vasilas432]

@darkstrider2
I have received a new OSSC after my first one died and I am checking for sync drops with Capcom. I will tell you what is going on in a little while.

[vasilas432]

I confirm that F3 is working now with OSSC like a charm! Thank you marqs
I tested one F3 board, but more will follow

[vasilas432]

Three questions I have are that setting H-PLL pre and post coast to 4 or leave them to default has no difference, crystal clear image in bothe cases.

Does everything play through the new cable via AV3 input? I tried a Capcom board and plays normaly. I didn’t try anything else.
Is it better for the new cable to be the most part a good scart cable (with just a male VGA connector on one end) or the most part a vga cable?(very short scart cable with a female VGA connector so a usual VGA male to male cable can be connected)

[vasilas432]

Darius Gaiden plays perfectly with a different F3 motherboard. Bubble Memories plays perfectly as well using one of the above motherboards

H-PLL pre and post coast need to be on 4 as Marqs said. Audio comes in from A3 and comes out through HDMI

Thank you again Marqs. Those F3 games look awesome through OSSC to my LG OLED B7.

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