Cheap, sturdy SCART to 'VGA' dsub15 adapter that works well!

[Josh128]

if you're going to connect composite video to anything on the VGA connector, it'd be vsync, not hsync.

not that I would want to connect CVBS to any pin on the VGA connector, but what is the reasoning being this statement?

I'd like to know this, too, considering all the pro AV gear (granted, not VGA monitors) I've seen that takes RGBS over DE-15 expects composite sync on HSync, not VSync.

Would it even work if VGA normally calls for 5Vp-p/TTL sync, and you're feeding it 1Vp-p/75Ohm/video-level composite sync contaminated with video data?

ATI VGA cards such as the Radeon 5450 do indeed output composite sync on the H-Sync pin. I just built a VGA and 1/8" Stereo audio to SCART for my CRTEmudriver / GroovyMAME system and can confirm this.

[Guspaz]

CVBS would be because that's what SCART is going to carry. You can feed it TTL CSYNC but that's a modification on the source side, SCART itself expects CVBS there.

I may be mistaken about csync being expected on the V sync pin. That said, if you've got the two BNC breakout cables as you've described, then just connect H to V sync. Or use a VGA-to-BNC breakout with a SCART-to-BNC breakout. This sort of thing is just a passive adapter, so it doesn't have the active circuitry to split the sync.

This isn't a generic adapter though, it's a proprietary Optoma adapter made for a few specific models of projectors (which label their DS-15 port as "VGA/SCART" and show this specific adapter in their user manuals). So they're not obligated to follow the convention about pinouts.

[oldgamer]

Nor should it be. This is a pin adapter, not a sync converter. SCART doesn't even have a dedicated sync line, and if you're going to connect composite video to anything on the VGA connector, it'd be vsync, not hsync.

But it shouldn't need any sync conversion as the snes and the genesis are giving composite sync (which the extrons support), not composite video, so no need for electronics.

The extrons at least take csync on the Hsync pin of the de-15 connector.

It seems only the rgb pins are connected on this dongle, neither of the hsync and vsync pins on the de-15 side seem to be connected to anything, I just tried every combination and nothing changes.

I wonder if the original device this dongle was meant for gives component video over the scart plug, or perhaps RGsB, as nothing else is possible.

[Guspaz]

It's meant for getting both RGB SCART and S-VIDEO into an Optoma projector via the VGA input. But the projectors have separate input modes (in the menu) to specify which of the three you're feeding in. There's no guarantee that it's a standard pinout. After all, VGA sync is TTL, and SCART sync is cvbs which is 75ohm. This is not a general purpose adapter, so they could be routing sync to a different pin than what VGA uses for sync, such as one of the DDC reserved pins. VGA-to-BNC breakouts are only going to connect five of the fifteen VGA pins, after all.

Another thought is, are you sure your SCART cable is sending sync down the same pin as the adapter expects? Sync on a SCART connector can be found on either pin 19 *or* 20 depending on the direction.

I suggest you poke at the thing with a multimeter. Put one end on SCART pin 19 and then check each VGA pin, and then do the same for SCART pin 20.

[pegboy]

I purchased one and tested it with a multimeter. On the VGA side, pin 13 (h-sync) is hooked up to pin 19 on the scart side.

[Josh128]

I purchased one and tested it with a multimeter. On the VGA side, pin 13 (h-sync) is hooked up to pin 19 on the scart side.

It should work for 15KHz VGA then. Is the v-sync VGA pin connected to anything on the SCART side?

[pegboy]

I purchased one and tested it with a multimeter. On the VGA side, pin 13 (h-sync) is hooked up to pin 19 on the scart side.

It should work for 15KHz VGA then. Is the v-sync VGA pin connected to anything on the SCART side?

Nope. Only the RGB, H-sync, and their respective ground pins are hooked up.

[Guspaz]

I think that narrows it down to either oldgamer having a scart cable with sync on pin 20, or a defective adapter.

[Josh128]

I purchased one and tested it with a multimeter. On the VGA side, pin 13 (h-sync) is hooked up to pin 19 on the scart side.

It should work for 15KHz VGA then. Is the v-sync VGA pin connected to anything on the SCART side?

Nope. Only the RGB, H-sync, and their respective ground pins are hooked up.

Why do you say that? RGB H-sync, and returns/grounds are all you need for 15KHz VGA when outputting composite sync from the video card, as with CRTEmudriver. Of course you'd have to get audio some other way, but it would work because composite sync is sent out on the H-sync pin.

[oldgamer]

Ok, I retested things and the dongle does work in the SCART to VGA direction, and does not work in the opposite direction.

This worked for me:

SNES scart rgbs->OP's dongle->vga to scart passive dongle->scart to component.

[strayan]

Ok, I retested things and the dongle does work in the SCART to VGA direction, and does not work in the opposite direction.

This worked for me:

SNES scart rgbs->OP's dongle->vga to scart passive dongle->scart to component.

Maybe I’m missing something but this chain makes no sense to me.

[kitty666cats]

Ok, I retested things and the dongle does work in the SCART to VGA direction, and does not work in the opposite direction.

This worked for me:

SNES scart rgbs->OP's dongle->vga to scart passive dongle->scart to component.

Maybe I’m missing something but this chain makes no sense to me.

Yup, me neither hehe. I approve of the madness though

What's this passive DE-15>SCART?