Skewing, Flagging and Bending on Screen

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thchardcore
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Skewing, Flagging and Bending on Screen

Post by thchardcore »

I use a Micomsoft Displ and xrgb-1 for my arcade setup. The line doubles are connected to a VGA CRT (Sony and Viewsonic). My issue is that certain arcade boards, namely Toaplan stuff, exhibit a skewing or flagging on the left side of the screen (in TATE, so top if horizontal).

I have tried every Extron box (203, SC210, 160, 580), and while some help a little, none have completely corrected the issue in full. My chain is Jamma> supergun with Tim Worthington's AV Driver set to 75ohm sync, scart cable to xrgb and then extron at end of chain.

My question is if I should be placing the extron before the xrgb and if anyone else has these issues and found a way to correct them. Could it just be my monitor?

Also, I tried the OSSC on the VGA input, but even with adjusting values, I never got an picture with these troublesome arcade boards.

Any help is greatly appreciated as it totally ruins what is otherwise a perfect setup.
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Re: Skewing, Flagging and Bending on Screen

Post by Fudoh »

Also, I tried the OSSC on the VGA input.
what exactly do you mean by that? Did you try the OSSC in conjunction with the XRGB or on its own?
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Re: Skewing, Flagging and Bending on Screen

Post by thchardcore »

I tried only the xrgb alone and the ossc alone. I did not chain them.

I have to ask, but the DAC here refers to which equipment?
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Re: Skewing, Flagging and Bending on Screen

Post by Fudoh »

I have to ask, but the DAC here refers to which equipment?
whatever you're using to convert from the OSSC's HDMI output to your monitors' analogue inputs.
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Re: Skewing, Flagging and Bending on Screen

Post by thchardcore »

It's the Porta one people recommend (it used to).

I really would like to correct this skewing on the xrgb and displ. I opened each unit and was able to turn the variable resistor enough to stop some jittering on the bottom of screen, but it did not fix the skewing, just reduced it some.
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maxtherabbit
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Re: Skewing, Flagging and Bending on Screen

Post by maxtherabbit »

have you tried turning the SERR setting on/off on the extron?
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Re: Skewing, Flagging and Bending on Screen

Post by thchardcore »

maxtherabbit wrote:have you tried turning the SERR setting on/off on the extron?
Of course. It doesn't appear to make any difference, which makes me question if it is incorrect to have it as the last item in the chain.
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Re: Skewing, Flagging and Bending on Screen

Post by fernan1234 »

You may have already tried this, and may not make a difference, but in my experience those Extron boxes tend to like TTL sync more rather than 75ohm, so if you can switch that there's a chance it would help.
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Re: Skewing, Flagging and Bending on Screen

Post by Xyga »

The Displ and Xrgb-1 can't accomodate every existing pcb on any display, even the Xrgb-2 with its AFC distortion correction feature can't solve all stability issues.

The [ micomsoft doubler > pcb > display ] relationship is far from being all-smooth, some combinations are perfect, some a bit shaky, and some just don't work well at all...
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Re: Skewing, Flagging and Bending on Screen

Post by orange808 »

OP might also consider using a different supergun. Is your solution homemade?
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Re: Skewing, Flagging and Bending on Screen

Post by thchardcore »

Xyga wrote:The Displ and Xrgb-1 can't accomodate every existing pcb on any display, even the Xrgb-2 with its AFC distortion correction feature can't solve all stability issues.

The [ micomsoft doubler > pcb > display ] relationship is far from being all-smooth, some combinations are perfect, some a bit shaky, and some just don't work well at all...
That sucks. Oddly, the XRGB-1 (3 dip version) works better with same games that the Displ doesn't handle well. For a simple line doubler, I wouldn't think there would be much in the way of issues with sync. Perhaps it is my monitors, as the Viewsonic flickers with most of the toaplan stuff while the Sony displays them well albeit with left side skew.
fernan1234 wrote:You may have already tried this, and may not make a difference, but in my experience those Extron boxes tend to like TTL sync more rather than 75ohm, so if you can switch that there's a chance it would help.
Ok. I will give that a go. Thanks.
orange808 wrote:OP might also consider using a different supergun. Is your solution homemade?
Yes, it is just a Mak Strike (bad IMO) modified with Tim's AV driver.
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Re: Skewing, Flagging and Bending on Screen

Post by the Goat »

I think the Extron 20x needs to be before the xrgb.
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Re: Skewing, Flagging and Bending on Screen

Post by thchardcore »

the Goat wrote:I think the Extron 20x needs to be before the xrgb.
I'll give that a try as well. Thanks.

If I go that route, I think I will need to attenuate the Extron sync output back down to sub 1v and 75ohm level.

For scart input to the OSSC, what are you guys doing to drop the voltages to the safe standards?
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Re: Skewing, Flagging and Bending on Screen

Post by cyborc »

thchardcore wrote:
the Goat wrote:I think the Extron 20x needs to be before the xrgb.
I'll give that a try as well. Thanks.

If I go that route, I think I will need to attenuate the Extron sync output back down to sub 1v and 75ohm level.

For scart input to the OSSC, what are you guys doing to drop the voltages to the safe standards?

470 ohm resistor in series on the sync line should do it.

From http://junkerhq.net/xrgb/index.php?title=OSSC
AV1 (RGB-SCART)
This input supports video in RGBS, RGsB (sync on green) and YPbPr formats. Composite video, luma or composite sync can be used as a sync source in RGBS mode. External sync splitters or boosters are generally not required or recommended as there is a built-in sync filter & separator in the ADC frontend. The sync input has 75 ohm termination, so a TTL-level sync signal should not be directly connected to the OSSC in order to avoid unnecessarily stressing the source console and/or OSSC. A 470 ohm series resistor on the console side of the cable is generally a good solution when using cables which are wired for the TTL-level sync output of a console. The video inputs also have standard 75 ohm termination, so arcade boards may need extra resistors on the cable when connected directly without using a Supergun.
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Re: Skewing, Flagging and Bending on Screen

Post by thchardcore »

cyborc wrote:
thchardcore wrote:
the Goat wrote:I think the Extron 20x needs to be before the xrgb.
I'll give that a try as well. Thanks.

If I go that route, I think I will need to attenuate the Extron sync output back down to sub 1v and 75ohm level.

For scart input to the OSSC, what are you guys doing to drop the voltages to the safe standards?

470 ohm resistor in series on the sync line should do it.

From http://junkerhq.net/xrgb/index.php?title=OSSC
AV1 (RGB-SCART)
This input supports video in RGBS, RGsB (sync on green) and YPbPr formats. Composite video, luma or composite sync can be used as a sync source in RGBS mode. External sync splitters or boosters are generally not required or recommended as there is a built-in sync filter & separator in the ADC frontend. The sync input has 75 ohm termination, so a TTL-level sync signal should not be directly connected to the OSSC in order to avoid unnecessarily stressing the source console and/or OSSC. A 470 ohm series resistor on the console side of the cable is generally a good solution when using cables which are wired for the TTL-level sync output of a console. The video inputs also have standard 75 ohm termination, so arcade boards may need extra resistors on the cable when connected directly without using a Supergun.
Thanks. I assume the rgb levels can be used without further modification? Does the extron push just the sync back to 5v TTL or the RGB lines as well?
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Re: Skewing, Flagging and Bending on Screen

Post by maxtherabbit »

extron does not amplify the RGB levels, they are good to use as is
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Re: Skewing, Flagging and Bending on Screen

Post by thchardcore »

So as a follow up, I tried every possible combination without success. I can't even get the Toaplan v2 pcbs to sync. OSSC reads 263p and Extron 203 states horizontal rate as 31khz!

Is there any device I could place before or after that would help normalize these odd sync rates to NTSC standard? Is a DVDO VP a workable solution with either the OSSC or the XRB-1?
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Re: Skewing, Flagging and Bending on Screen

Post by Xyga »

It's been ages since the last time I've tried arcade boards directly on a DVDO, plus that was for output on a flat panel, not a crt, but I remember the VP50 Pro could pass non-60 material the VP30 couldn't.
Never tested the limits of that flexibility though as I didn't have anything like for instance an irem m72 or seibu spi to test.
I may have tried a couple toaplan2 boards though, but I don't remember anything about the results, sorry.

Among all doublers and scalers with low lag the XRGB-2 and VP50 Pro might be the two most capable at taming arcade boards, whether standalone or chained, but that's still mostly speculation since too few actual tests have been made.
Also the XRGB-2 has that annoying cropping I just can't stand.
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Re: Skewing, Flagging and Bending on Screen

Post by Fudoh »

Something's not right here.

I can't directly confirm functionality using the OSSC, but the Toaplan v2 boards (Batrider for example) are listed as working (and even tested by marqs himself) right here:

https://docs.google.com/spreadsheets/d/ ... =628991590

I know that arcade boards can be tricky, but I HIGHLY doubt that the OSSC itself is the problem here. It's either your way of connecting the PCBs (and whatever your supergun does to the signals) or it's your DAC (that you use to convert the OSSC's digital output to your VGA monitors).

Maybe start a thread on the VGP boards or just PM marqs about this one. I mean it's very special AND he has tested a Toaplan v2 board.
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Re: Skewing, Flagging and Bending on Screen

Post by Xyga »

Or even both of his monitors...I've seen even arcade cabs bend/skew some pcb's, needed some sync adjustments directly on the chassis, so why not pc monitors?
If it happens even with the Micomsofts directly wired to either monitor, then the latter are the one I'd see as suspicious.
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Re: Skewing, Flagging and Bending on Screen

Post by thchardcore »

Fudoh wrote:Something's not right here.

I can't directly confirm functionality using the OSSC, but the Toaplan v2 boards (Batrider for example) are listed as working (and even tested by marqs himself) right here:

https://docs.google.com/spreadsheets/d/ ... =628991590

I know that arcade boards can be tricky, but I HIGHLY doubt that the OSSC itself is the problem here. It's either your way of connecting the PCBs (and whatever your supergun does to the signals) or it's your DAC (that you use to convert the OSSC's digital output to your VGA monitors).

Maybe start a thread on the VGP boards or just PM marqs about this one. I mean it's very special AND he has tested a Toaplan v2 board.
I don't believe all Toaplan v2 boards are equal. For instance, Battle Gregga outputs fine - no issues with any converter or line doubler. Same with Tatsujin Oh. However, Batsugun, V-V and Foxeight all show the same issue - they either sync with flagging/skewing or they simply don't sync at all.

I'm boiling this down to my monitors - I tried a small older (1991) Sony VGA screen and it displayed only slight flagging/skewing.

I am curious if there is a way to adjust the sync internally on a VGA monitor to compensate for this.
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Re: Skewing, Flagging and Bending on Screen

Post by thchardcore »

So apparently Micomsoft has a settings tweak for these boards. If I buy an XRGB3, will I be able to load this profile into it. I assume this works in B1 mode so I can bypass any lag?

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Re: Skewing, Flagging and Bending on Screen

Post by Xyga »

That would be in B0 (scaling) mode, so no.
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Re: Skewing, Flagging and Bending on Screen

Post by thchardcore »

I found some of your old posts Xyga on the AVSforum and it appears I really do need a VP30+ABT 102 or a VP50 Pro.

Thank you for the direction.
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Re: Skewing, Flagging and Bending on Screen

Post by Xyga »

That's very old info, since then I've found that the VP50 Pro has a greater tolerance with arcade boards though again I haven't tested enough pcb's to tell about how much more either.
Every machine has its quirks and limits, for instance I don't remember which of the 30 or the 50 it was but I remember Turbo Force (61~Hz game) wouldn't display via the scaler while it worked directly on my Sony W6.

It would be wiser to go for an XRGB-2 if you want to be sure, IMHO, to this day it's still the only machine featuring anti-skewing/flagging/bending, it was specifically designed to normalize troublesome pcb's.
Its only flaw is that it cuts a few lines at the bottom with some games, and the main power switch is kind of shit but fixable in case.

Then chaining a doubler and a scaler is an interesting thing, but the rationality of it depends on how far X or Y combo has been challenged, really, too few people have gone the doubling 'n scaling way for an arcade setup even back in the day, and we did not receive enough feedback to be able to tell "yes x pcb will work with y doubler or scaler" or "no it wont".
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Re: Skewing, Flagging and Bending on Screen

Post by thchardcore »

Just for the record, I read your post but did not reply. Thank you. I have tried the XRGB2 to fix this and while it presented an image better than what the other line doublers achieved, it still has some skewing.
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