Sync Separator

Mindl3ss

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I recently picked this monitor up. Doesen't have input for an arcade, but it's got a 9-pin input on it.

The 9-pin needs a separate sync, while I want to use it as an arcade monitor. So I need to split the sync up.

Any adapters out there, or an easy way to wire up my own?
 
Get an LM1881. It's a 8-pin sync seperator chip. Very easy to use. Datasheet is online. There's a more modern replacement, but the 1881 is still in full production. Let me know if you need more info.
 
If it's a computer monitor, it probably accepts only POSITIVE sync.

it's not a computer monitor. It has a switch that will change between positive and negative sync.

You don't need any fancy chips do separate sync for a monitor like that... only about 10 cents worth of parts.

What parts would that be, and where can I find out how?

I posted the model number with some questions about the options it has on it a while back, but after a bump and no responses, at all, I figured I'd asked the wrong questions or something.
 
Originally Posted by HudsonArcade
You don't need any fancy chips do separate sync for a monitor like that... only about 10 cents worth of parts.
What parts would that be, and where can I find out how?
Yeah, I'm curious too. I mean...I could do it a bunch of ways, but it'd be a buck or two.

[EDIT]
Wait...does your monitor need COMPOSITE sync? I read your original post as "seperate v-sync and h-sync"....it was really late for me. If you only need c-sync, then yeah. You can probably make it work with a generic transistor (2n3904 is good) and a couple of resistors.
 
Yeah, I'm curious too. I mean...I could do it a bunch of ways, but it'd be a buck or two.

[EDIT]
Wait...does your monitor need COMPOSITE sync? I read your original post as "seperate v-sync and h-sync"....it was really late for me. If you only need c-sync, then yeah. You can probably make it work with a generic transistor (2n3904 is good) and a couple of resistors.

I'm going off of this page's description of a 9-pin video port.

http://pinouts.ru/Video/VGA9_pinout.shtml

They show a V-sync and H-sync. So, I assumed that I need separate sync.

Here's an image of the back of the monitor:
attachment.php


I really need this to work, because it's what I have, and I can't afford another monitor right now.
 
Are you sure it *needs* separate sync? Have you tried just feeding composite sync into the horizontal sync input?

Most computer monitors will put up with that, since there are some computer systems that use it (Sun).

-Ian
 
Are you sure it *needs* separate sync? Have you tried just feeding composite sync into the horizontal sync input?

Most computer monitors will put up with that, since there are some computer systems that use it (Sun).

-Ian

I haven't tried yet. I'm just a little worried about ruining it or something, so I figured I'd try to get some suggestions first
 
Getting the Sync wrong won't harm the monitor, it just won't sync... So it's safe to try.

Based on the pic you posted, flip the FBAS/RGB switch to RGB, hook up to + Sync and give it a go.
 
Yeah, sure is.

I don't have anything with SCART though...

I tried the FBAS with a composit video source... didn't show anything. Soon as I get the rest of my harness put together, I'll try it out, and let you guys know the results
 
Well... I hooked it up...

here's what I'm getting:
attachment.php


You can make out that the game is running, you can barely make out the attract mode on Fatal Fury

I combined all the grounds on the 9-pin to the single video ground on the harness. I ran the composite sync from the harness to the H-sync on the 9-pin

I ignored the V-sync on the 9-pin.

Would it be safe to run the composite sync to the V-sync and H-sync on the monitor?
 
Last edited:
Would it be safe to run the composite sync to the V-sync and H-sync on the monitor?

Yeah. That's not going to hurt anything. It'll either work, or it won't.

You did remember to set the sync polarity switch to negative, right?

SCART uses composite sync. If the RGB setting is one of those that allows you to use either jack, then you can probably run the composite sync over to the proper pin on the SCART connector.

-Ian
 
I would think you would want that rgb switch set to an (analog) and not ttl (digital)
 
I would think you would want that rgb switch set to an (analog) and not ttl (digital)

Yes, definitely. I didn't notice that switch before, but yeah, you want it to analog. It won't affect the sync (sync is always pretty much digital), but it will affect the number of colors you can display. With digital you're only going to get about eight...

-Ian
 
I did check both settings on the switches. I didn't know what the an and ttl switch would do. I know ttl is transistor transistor logic, from some of the digital classes I've taken, but I guess I didn't know that's what the switch did.

I had it set to negative sync first. But I did try it with the positive just to make sure

I'll combined the sync's and then see if I can try the SCART sync
 
Well, I've tried just about every combination now.

I did sync from harness to the H-sync, the V-sync, BOTH sync, the SCART sync and every one gives me the same as the picture up there.
 
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