BVM-A20F1M Sega consoles Sync problems

[jwrose]

You're misunderstanding sync strippers, at least in this context. The sync stripper won't recreate the missing signals, it will just separate sync information from a given signal.

Makes sense. I kinda wondered because of the name. I guess I've never understood how/what types of devices create a new signal when a sync stripper is used. Is it when a device uses something like sync on luma and needs to get rid of the normal sync?

[skum]

You're misunderstanding sync strippers, at least in this context. The sync stripper won't recreate the missing signals, it will just separate sync information from a given signal.

Makes sense. I kinda wondered because of the name. I guess I've never understood how/what types of devices create a new signal when a sync stripper is used. Is it when a device uses something like sync on luma and needs to get rid of the normal sync?

A sync stripper "strips" the sync from a composite video signal for instance. You then get CSYNC, or composite sync, where H and V sync are merged. At the same time the sync strippers I know also give you discrete H and V sync signals, but its the same signals as in the original, the information as such doesn't change. CSYNC can be desired for several reasons, including noise/image defects like flagging or whatever it's called or because some monitors simply won't work without it.

[jwrose]

A sync stripper "strips" the sync from a composite video signal for instance. You then get CSYNC, or composite sync, where H and V sync are merged. At the same time the sync strippers I know also give you discrete H and V sync signals, but its the same signals as in the original, the information as such doesn't change. CSYNC can be desired for several reasons, including noise/image defects like flagging or whatever it's called or because some monitors simply won't work without it.

Ah, gotcha. Thanks for the description. OK, what I didn't understand previously was that the goal of a sync stripper was to get rid of the previous sync to add csync.

[RGB0b]

This page explain why the issue occurs on these monitors/input cards: https://www.retrorgb.com/bkm-68x.html

And Ste's writeup of how sync gets messed up in the console itself: https://www.retrorgb.com/engineering-cs ... ision.html

There's still talk of different fixes for the A-Series, as well as the DxH series, but for now the latest gscartsw fixes SMS.

[jwrose]

This page explain why the issue occurs on these monitors/input cards: https://www.retrorgb.com/bkm-68x.html

And Ste's writeup of how sync gets messed up in the console itself: https://www.retrorgb.com/engineering-cs ... ision.html

There's still talk of different fixes for the A-Series, as well as the DxH series, but for now the latest gscartsw fixes SMS.

Thanks! What in the gscartsw fixes the issue?

[RGB0b]

Hey, I had an idea last night and it works...mostly. I took an arcade board that has the same sync issue we all talk about and ran it through the OSSC. So:

Console/Board -> OSSC in passthrough mode -> Cheap DAC -> Component video input on my D9H

Direct RGB: https://imgur.com/AfEdeD8

Through OSSC, then DAC: https://imgur.com/8IIcWdm

It's the same DAC I link to in my Amazon store. The HDMI to VGA one can be used as well, as long as you use a sync combiner (NOT just a Y cable!!!): https://www.amazon.com/shop/retrorgb


Does anyone with an A-Series BVM and a BKM-68x want to give this a try? I assume you'll need to mess with the OSSC's settings some more, but if you already own an OSSC, it might be a temporary solution.

[jwrose]

Hey, I had an idea last night and it works...mostly. I took an arcade board that has the same sync issue we all talk about and ran it through the OSSC. So:

Console/Board -> OSSC in passthrough mode -> Cheap DAC -> Component video input on my D9H

Direct RGB: https://imgur.com/AfEdeD8

Through OSSC, then DAC: https://imgur.com/8IIcWdm

It's the same DAC I link to in my Amazon store. The HDMI to VGA one can be used as well, as long as you use a sync combiner (NOT just a Y cable!!!): https://www.amazon.com/shop/retrorgb


Does anyone with an A-Series BVM and a BKM-68x want to give this a try? I assume you'll need to mess with the OSSC's settings some more, but if you already own an OSSC, it might be a temporary solution.

Ha, you beat me to it. That's cool! I was considering trying something similar with my D series but hadn't got around to it. I did try converting to component from RGB, but that didn't help. I'll try to give it a shot shortly. If it works, it works! Long term i'm hoping to find something that wouldn't require tying up my OSSC as I currently have it in my chain for an additional optional output. I'll report back soon.

Another question- are there are any known hardware mods that fix this? I saw somewhere some type of RGB mod for the SMS, but I don't know if it would do anything to resolve this.

[RGB0b]

There's no hardware mods that fix this, but there are a few devices in the works that might. Progress is slow, but we're on it.

[jwrose]

There's no hardware mods that fix this, but there are a few devices in the works that might. Progress is slow, but we're on it.

cool! Thanks for all you do for the retro community. So, we're talking possible external device(s)? (just trying to figure out if its better recap my SMS sooner if its not an internal mod)

Anyway, I did a quick test and can report success (mostly!)

https://ibb.co/GHqDHT9
https://ibb.co/MpY0t7Z

So, everything looked great as far as how the image was aligned and displaying. The one issue I did have (and you can kinda see this) is the image was VERY dim. My guess is that this is do to my cheap HDMI > component converter I have.

So, extra detail, this was a US SMS 1 > OSSC > hdmi to comp (cheap) converter > BVM-D14H5U

[RGB0b]

Yes, it would be an external box...assuming we can get it working. If you have the time and ability though, I think recaps are always a good idea, just for preservation.

Very cool to see it working. I'll try and test some more myself if I have time, but I'm pretty swamped these days. I'm also kinda curious which OSSC settings are still active in "passthrough" mode. Maybe there's still some tweaking that can be done.

Overall, at least it's a zero-lag solution!

[jwrose]

Yes, it would be an external box...assuming we can get it working. If you have the time and ability though, I think recaps are always a good idea, just for preservation.

Very cool to see it working. I'll try and test some more myself if I have time, but I'm pretty swamped these days. I'm also kinda curious which OSSC settings are still active in "passthrough" mode. Maybe there's still some tweaking that can be done.

Overall, at least it's a zero-lag solution!

Great- thanks for the extra info- I hope you're able to get something working for SMS! I'm going through the process of getting all my stuff recapped- SMS is next since I won't be waiting on a hypothetical internal mod (5 systems down, 11 to go!)

Also, I haven't updated my OSSC yet, so this was off of firmware 0.81a. (Its been working great for everything I've tossed at it- so I haven't been in a rush).

Yep, its nice to have this option, at least.

[PeterWar]

Hey, I had an idea last night and it works...mostly. I took an arcade board that has the same sync issue we all talk about and ran it through the OSSC. So:

Console/Board -> OSSC in passthrough mode -> Cheap DAC -> Component video input on my D9H

Direct RGB: https://imgur.com/AfEdeD8

Through OSSC, then DAC: https://imgur.com/8IIcWdm

It's the same DAC I link to in my Amazon store. The HDMI to VGA one can be used as well, as long as you use a sync combiner (NOT just a Y cable!!!): https://www.amazon.com/shop/retrorgb

Does anyone with an A-Series BVM and a BKM-68x want to give this a try? I assume you'll need to mess with the OSSC's settings some more, but if you already own an OSSC, it might be a temporary solution.

I have a BVM-A20F1M and BKM-68x and OSCC. I Also have BKM-61D and BKM-62HS input boards. I've tried the following so far:

Nintendo Switch->MicroConverter HDM to SDI->BKM-62HS (Works in HDSDI 444 YPBR Mode)

MegadrivePALRGB->gscartsw->OSCC->MicroConverter HDM to SDI->BKM-62HS (Does NOT work)

MegadrivePALRGB->gscartsw->OSCC->MicroConverter HDM to SDI->BKM-61D (Does NOT work)

I'm no expert in OSCC as I really bought it to try to solve this issue, please tell me what settings to try and will do it today. If I understand you well, the setup that you would want me to try is:

MegadrivePALRGB->gscartsw->OSCC->HDMI to YPbPr Converter->BKM-68X is that right? if so, would an HDMI to SCART RGB also work? If that's the case were could I source a good one in Spain?

[jwrose]

Hey, I had an idea last night and it works...mostly. I took an arcade board that has the same sync issue we all talk about and ran it through the OSSC. So:

Console/Board -> OSSC in passthrough mode -> Cheap DAC -> Component video input on my D9H

Direct RGB: https://imgur.com/AfEdeD8

Through OSSC, then DAC: https://imgur.com/8IIcWdm

It's the same DAC I link to in my Amazon store. The HDMI to VGA one can be used as well, as long as you use a sync combiner (NOT just a Y cable!!!): https://www.amazon.com/shop/retrorgb

Does anyone with an A-Series BVM and a BKM-68x want to give this a try? I assume you'll need to mess with the OSSC's settings some more, but if you already own an OSSC, it might be a temporary solution.

I have a BVM-A20F1M and BKM-68x and OSCC. I Also have BKM-61D and BKM-62HS input boards. I've tried the following so far:

Nintendo Switch->MicroConverter HDM to SDI->BKM-62HS (Works in HDSDI 444 YPBR Mode)

MegadrivePALRGB->gscartsw->OSCC->MicroConverter HDM to SDI->BKM-62HS (Does NOT work)

MegadrivePALRGB->gscartsw->OSCC->MicroConverter HDM to SDI->BKM-61D (Does NOT work)

I'm no expert in OSCC as I really bought it to try to solve this issue, please tell me what settings to try and will do it today. If I understand you well, the setup that you would want me to try is:

MegadrivePALRGB->gscartsw->OSCC->HDMI to YPbPr Converter->BKM-68X is that right? if so, would an HDMI to SCART RGB also work? If that's the case were could I source a good one in Spain?

What he posted was essentially testing out just doing RGB Scart > OSSC > HDMI to YPbPr converter > BVM, the gscartsw wasn't part of the chain he was asking to test. For me, this worked. Separately, though, the gscartsw is supposed to resolve the issue as well without the OSSC.

So PAL Megadrives have the same issue? NTSC Master System does but NTSC Genesis does not.

[RGB0b]

If I understand you well, the setup that you would want me to try is:

MegadrivePALRGB->gscartsw->OSCC->HDMI to YPbPr Converter->BKM-68X is that right?

Yes.

if so, would an HDMI to SCART RGB also work?

No, because you'd specifically want the OSSC in passthrough mode.

Other options might be the RetroTINK2x in passthrough mode, or the 2x SCART with scanlines on, both with the cheap HDMI to Component converter.

[RGB0b]

the gscartsw wasn't part of the chain he was asking to test

The gscartsw isn't required for this, but it won't hurt.

[PeterWar]

I bought the Portta HDMI to YPbPr Concerter to give this a try. Will report when it arrives.

[Ikaruga11]

Do any of these solutions that fix sync (Extron 203rxi, 580xi, gscartw, OSCC, etc.) introduce any input/display lag or picture quality degradation?

[jwrose]

Do any of these solutions that fix sync (Extron 203rxi, 580xi, gscartw, OSCC, etc.) introduce any input/display lag or picture quality degradation?

Speaking from what I have experience with:
ossc: no- it does line doubling instead of upscaling which is why it's super fast. I've had games going simultaneously on my BVM and an LCD monitor via OSSC and could not visually tell a difference in inputs.
Extron 203rxi:no- at least I've never noticed any or heard of people complain about it. I use it for 2 different systems and it works fantastic.

[Ikaruga11]

Do any of these solutions that fix sync (Extron 203rxi, 580xi, gscartw, OSCC, etc.) introduce any input/display lag or picture quality degradation?

Speaking from what I have experience with:
ossc: no- it does line doubling instead of upscaling which is why it's super fast. I've had games going simultaneously on my BVM and an LCD monitor via OSSC and could not visually tell a difference in inputs.
Extron 203rxi:no- at least I've never noticed any or heard of people complain about it. I use it for 2 different systems and it works fantastic.

Thanks

Yep. SERR feature on Extron RGB devices can fix the signal for Neo Geo AES and TG16, but Master System signals seems to be fixable with a gscartsw.

I personally have experience solving the first two with an Extron RGB 203 but hoping there's another way to fix the SMS signal (cheaper than a gscartsw).

So I don't need an Extron 580xi to fix my Japanese 3-6 Neo Geo AES if I already have an Extron 203rxi?

[jwrose]

So I don't need an Extron 580xi to fix my Japanese 3-6 Neo Geo AES if I already have an Extron 203rxi?

I can't say absolutely since i don't have a JP Neo Geo, but I'll explain my setup.

I have a US Neo Geo AES and a Turbografx 16. Both have similar display issues that I think is technically called flagging. The AES pulls the top of the image to the left. The TG is a bit more messed up than that, and the colors are a little weird. The SERR feature on my Extron RGB 203 Rxi fixes both.

So, that's the short answer.

If you're looking to utilize the same Extron RGB on two systems, you can either unhook them each time to swap what's using the Extron RGB, or you can use an Extron Crosspoint and keep everything hooked up all the time. I'll shorthand this to make it simple since my setup is a little complicated. On my Crosspoint, I use
Input 1: all my RGB SCART devices running from an Otaku Scart switch
Input 8: input from my Extron RGB 203 Rxi

Output 1: to my BVM (with OSSC chained to it from my BVM output)
Output 3: out to my Extron RGB 203 Rxi

(Obviously input numbers don't matter, but that's what I'm using)
So, this lets me select Input 1 and map it to Output 3 to fix the signal. I can then select Input 8 and map it to Output 1, which takes the fixed signal and sends it to the monitor. No input lag that i've ever noticed. It essentially "threads" the signal into the crosspoint, back out, back in, and back out to the monitor. That way I can play those two systems without issue, and then I can just do Input 1 to output 1 for systems that don't need the RGB Rxi. I do the same thing for my RGB2COMP if I want to send a system over to my Wega. That's how I play my SMS since it doesn't play nice with the BVM and the RGB 203 Rxi doesn't fix that signal.

[PeterWar]

Mind that I bought an Extron 580xi to try to fix my problems and that alone did not fix my Neo Geo AES skew problem. I have a high serial number Neo Geo AES, presently I play Neo Geo in composite, it is not optimal but at least I can enjoy it.

[daty2k1]

What I find really strange is that most problems I see reported here are skewed pictures and strange colors. However I've never experienced something like that.

For me it either works perfectly or I get a rolling picture.

[jwrose]

Mind that I bought an Extron 580xi to try to fix my problems and that alone did not fix my Neo Geo AES skew problem. I have a high serial number Neo Geo AES, presently I play Neo Geo in composite, it is not optimal but at least I can enjoy it.

My AES is a low serial number. Unfortunately, the label with the serial number was apparently removed by a previous owner, but my modder noted it was a different and the earliest model than he had seen based on the components. So, there's probably no way to know for sure unless you tried it, but the 203 Rxi did it perfectly for me. That said, I did have to place the 203 in my setup chain AFTER the RGB inputs went into my Crosspoint. Initially I tried running it from
AES > Extron RGB 203 > Crosspoint > BVM
and that didn't work. Someone on another forum suggested I try this:
AES > Crosspoint > Extron RGB 203 > BVM
and it fixed it. I have no idea why that would make a difference since the Crosspoint doesn't do any encoding.

What I find really strange is that most problems I see reported here are skewed pictures and strange colors. However I've never experienced something like that.

For me it either works perfectly or I get a rolling picture.

huh, I don't know. Are you using a BVM D series or A series?
My TG16 does a weird flickering thing, too- but I don't really get a rolling image.

[Ikaruga11]

Mind that I bought an Extron 580xi to try to fix my problems and that alone did not fix my Neo Geo AES skew problem. I have a high serial number Neo Geo AES, presently I play Neo Geo in composite, it is not optimal but at least I can enjoy it.

My AES is a low serial number. Unfortunately, the label with the serial number was apparently removed by a previous owner, but my modder noted it was a different and the earliest model than he had seen based on the components. So, there's probably no way to know for sure unless you tried it, but the 203 Rxi did it perfectly for me. That said, I did have to place the 203 in my setup chain AFTER the RGB inputs went into my Crosspoint. Initially I tried running it from
AES > Extron RGB 203 > Crosspoint > BVM
and that didn't work. Someone on another forum suggested I try this:
AES > Crosspoint > Extron RGB 203 > BVM
and it fixed it. I have no idea why that would make a difference since the Crosspoint doesn't do any encoding.

What I find really strange is that most problems I see reported here are skewed pictures and strange colors. However I've never experienced something like that.

For me it either works perfectly or I get a rolling picture.

huh, I don't know. Are you using a BVM D series or A series?
My TG16 does a weird flickering thing, too- but I don't really get a rolling image.

Is your US Neo Geo AES a 3-1 (first hardware version) by chance? Someone told me that his Neo Geo AES was a 3-1 US model and had no sync issues with RGB on the BKM-68X. Would putting the Extron 203rxi after the Extron Crosspoint mess up other consoles when the sync fix is adjusted for Neo Geo AES?

[daty2k1]

What I find really strange is that most problems I see reported here are skewed pictures and strange colors. However I've never experienced something like that.

For me it either works perfectly or I get a rolling picture.

huh, I don't know. Are you using a BVM D series or A series?
My TG16 does a weird flickering thing, too- but I don't really get a rolling image.

It's a A series with a BKM-68x. I don't know if it matters but all my consoles are PAL save for the N64.

If it can help anyone, here are the results of my testing:



Edit: I realize that I marked the NeoGeo as "OK" for NTSC but it works only with a custom version of the core.

[jwrose]

Is your US Neo Geo AES a 3-1 (first hardware version) by chance? Someone told me that his Neo Geo AES was a 3-1 US model and had no sync issues with RGB on the BKM-68X. Would putting the Extron 203rxi after the Extron Crosspoint mess up other consoles when the sync fix is adjusted for Neo Geo AES?

I'm not sure which mine is. How can I tell? I get the flagging issues but sync seems just fine as the image complete, just distorted.

Your other question about Crosspoint > Extron RGB 203rxi causing issues for other systems is a good one and I should have addressed that. Yes, it does cause issues. That's the exact issue I'm bypassing by having the weird setup I described earlier (having the ability to route systems through it by using an extra input/output on my crosspoint, opting to avoid using it). This lets me fix signals that need fixing and no messing up signals that are fine already without having to unhook anything.

[jwrose]

It's a A series with a BKM-68x. I don't know if it matters but all my consoles are PAL save for the N64.

If it can help anyone, here are the results of my testing:



Edit: I realize that I marked the NeoGeo as "OK" for NTSC but it works only with a custom version of the core.

Huh, that is really interesting information. So, this whole time I've been assuming I'm using the same component card because of the description of the issue, etc. I fired mine up and checked and I'm actually doing a D series with a BKM-129X

Maybe it doesn't matter and they essentially process things the same, but definitely worth noting. Just to reiterate, it has issues with AES, TG16, and SMS. Extron 203 rxi fixes it for AES and TG16, but not SMS.

[daty2k1]

I see. Then with the D Series you have access to VCR mode which can help with most of theses issues no?

[jwrose]

I see. Then with the D Series you have access to VCR mode which can help with most of theses issues no?

No, I don't. I think it's in there somewhere but I've always seen it greyed out. Maybe because I'm using RGB? Either way it's not an option for these systems.

[daty2k1]

I see. Then with the D Series you have access to VCR mode which can help with most of theses issues no?

No, I don't. I think it's in there somewhere but I've always seen it greyed out. Maybe because I'm using RGB? Either way it's not an option for these systems.

Ah strange. I found this video if it's any help:
https://youtu.be/6_2_OgrMPcg