Modified CGA to VGA Scaler to accept clean sync RGB SCART

[ckong]

Guys, I need some help.

Like fagin I also want to connect my lowres consoles to highres (VGA and HD) monitors/tv's/whatever and create scanlines with the SLG 3000:

(RGB scart) console > homemade sync splitter > scaler > SLG 3000 > monitor.

So I tried to built the same sync splitter/amplifier which fagin made. And although I had made one before, this time it didn't work. Whatever I tried, and I followed fagin's tut to the letter, I always get the hated message 'no signal'. I know that my cheap Ebay scaler is working, because I can get into the menu and when I connect an XBOX 360 to it, VGA on both sides, the monitor displays the 360 menu.

Today I had a brilliant idea, I thought. Why not use the scart>jamma adapter from Viletim. it outputs RGB and composite sync on screw terminals. Piece of cake, so I came up with this:



Of course I connected a 5V power supply to the scaler, which also gives juice to Viletim's adapter (measured at the screw terminals, +5.31V). I then hooked up various lowres consoles through RGB scart via Viletim's adapter to the scaler, and the scaler connected through VGA to various Highres monitors (output from the scaler: 640x480). At this point I didn't include the SLG 3000 yet because I still each time get the message 'no signal'.

What am I doing wrong??

[fagin]

How are you powering the scaler.... where is the power feed coming from (just to confirm)? From the picture you are expecting to power the scaler from the JAMMA connector. Is that correct?

What input have you chosen on the scaler? RGBs?

[ckong]

I power the scaler by an external power supply (5V power adapter connected to the wall socket). This makes the scaler run. And I have the 2 screw terminals (5V and ground) from Viletim's adapter connected to the 2-pin power connector on the scaler. This 2-pin connector deliveres 5V when the scaler is turned on (pass through from the power plug) and powers Viletim's adapter.

This is OK I guess because when I put the 5V power adapter in the wall socket, the scaler turns on and is working (I can get into the menu on my LCD TV) and Viletim's adapter is also powered at the same time (I measure 5,31V on Viletim's 5V screw terminal).

[fagin]

OK... what is the scaler set to - RGBs as the input?

[ckong]

... RGBs as the input?

yes.

[fagin]

OK... Assuming the sync signal is of the correct type, you should try and reset the scaler. I think you keep AUTO button pressed for longer than 5s. Your clamp settings might be wrong, so the reset should rectify this.

Also the psu should be a minimum of 2amps.

[ckong]

Okidoki, will try that tomorrow.

[viletim]

Of course I connected a 5V power supply to the scaler, which also gives juice to Viletim's adapter (measured at the screw terminals, +5.31V). I then hooked up various lowres consoles through RGB scart via Viletim's adapter to the scaler, and the scaler connected through VGA to various Highres monitors (output from the scaler: 640x480). At this point I didn't include the SLG 3000 yet because I still each time get the message 'no signal'.

The JAMMA adapter runs on 12V only. The 5V connection does not power anything. You can verify this by observing the unlit power light.

[fagin]

[ckong]

Allright, then I will try a 12V adapter, connected to your (Viletim's) adapter. I hope that it will solve my problem and I will report about it later.

[fagin]

ckong,
Assuming this then works, if you want to post pictures of your LM circuit I can try to deduce why it is not working (as it should and I have a done a few now for this scaler and not had a problem with any of them).

[ckong]

SUCCESS thanks Viletim, to make me aware of my error.

So, for anyone who wants to use the above shown scaler with a lowres RGB scart console (and a SLG 3000), but can't make a (working ) sync separator/amplifier circuit, I can confirm that the following setup also works:

(RGB scart) console > Viletim's adapter > CGA 2 VGA scaler (for example the one shown in my previous post above) > SLG 3000 > LCD TV

It's very easy, just power Viletim's adapter through the screw terminals with a 12V adapter and connect the RGBSGr screw terminals with wires to the 5-pin connector on the scaler. Power the scaler (5V, 2A) and voila. And don't forget to set the video input on the scaler to RGBS

[Almighty]

Great job ckong!

i think i will order one to
You have some pictures running it with the SLG 3000

It's very easy, just power Viletim's adapter through the screw terminals with a 12V adapter

Using just a normal adapter and connect the wires to 12V and ground right?
You can make a picture ckong , because the one above is 5V. and ground am i right?

[ckong]

Using just a normal adapter and connect the wires to 12V and ground right?
You can make a picture ckong , because the one above is 5V. and ground am i right?

Yep, an ordinary 12V adapter (or for instance a PC power supply with 12V output or a Jamma switch supply).

In the picture above it shows indeed 5V and ground, but you need 12V, so just use the the (3rd) screw terminal for 12V instead of the 2nd screw terminal and you are good.

An additional advantage of using Viletim's adapter is that you get easy access to Brigtness and Contrast control and amplified stereo audio output.

And it looks great with the SLG 3000.

[Almighty]

An additional advantage of using Viletim's adapter is that you get easy access to Brigtness and Contrast control and amplified stereo audio output.

yup, just what i thought

if you got some time show us some nice pictures

[Trevor spencer]

An additional advantage of using Viletim's adapter is that you get easy access to Brigtness and Contrast control and amplified stereo audio output.

if you got some time show us some nice pictures

yes please

[matrigs]

i am kind of confused with this thing.

the sync stripper is supposed to split the sync signal so that you can connect rgb scart signals to rgbhv inputs right ?

i understand that you want to do this in order to connect the consoles to the rgbhv input of this ebay pcb.

but - the manual of this states it also accepts rgbs inputs which afaik is the signal used by rgb scart ? or are they different ?

please correct me if i'm wrong

[Fudoh]

The converter is built for typical RGB signals from Jamma boards. That's RGBs, but with clean sync. Home systems often have RGBs but with composite video as sync. The LM1881 here is used to clean up the sync signal to make it compatible, not for actual sync seperation.

[matrigs]

The converter is built for typical RGB signals from Jamma boards. That's RGBs, but with clean sync. Home systems often have RGBs but with composite video as sync. The LM1881 here is used to clean up the sync signal to make it compatible, not for actual sync seperation.

i was unaware of the fact that there are different rgbs standards. thats horribly confusing.

[fagin]

There isn't different RGBs standards. RGBs is RGB and Sync, simple as. Composite sync is not a proper sync signal as it contains other "data" and is not classed as a pure sync signal. SCART RGB input knows what type of sync signal to expect (composite), RGBs expects a clean sync. Don't confuse the two.

[matrigs]

thanks for clarifying.

just one other thing - you are actually also using the vertical sync from the 1881 and connecting the whole thing to the rgbhv port.

would it be possible to connect it to rgbs without the vertical sync ? is there any benefit from using vertical sync ?

[Fudoh]

As you can see from ckong's picture right on top of this page, composite sync by it's own is fine as well...

[matrigs]

As you can see from ckong's picture right on top of this page, composite sync by it's own is fine as well...

that's why i was asking - i thought that there are benefits from using also vertical sync

[mesmer]

There isn't different RGBs standards. RGBs is RGB and Sync, simple as. Composite sync is not a proper sync signal as it contains other "data" and is not classed as a pure sync signal. SCART RGB input knows what type of sync signal to expect (composite), RGBs expects a clean sync. Don't confuse the two.

You mean "composite video"

composite sync = clean sync

[fagin]

There isn't different RGBs standards. RGBs is RGB and Sync, simple as. Composite sync is not a proper sync signal as it contains other "data" and is not classed as a pure sync signal. SCART RGB input knows what type of sync signal to expect (composite), RGBs expects a clean sync. Don't confuse the two.

You mean "composite video"

composite sync = clean sync

Yes.. sorry.

[mesmer]

matrigs,
What console are you connecting to the CGA-VGA scaler? You might not need a LM1881 circuit. Some/Many consoles output composite sync. A SCART cable won't have it, but you can build your own cable.

Have a look at viletim's site

Also, here under AV Port Pinouts.

[Sparda]

any news for the Sync Strike project ?

[Almighty]

any news for the Sync Strike project ?

+2

[Sparda]

any news for the Sync Strike project ?

+2

+100

[ckong]

An additional advantage of using Viletim's adapter is that you get easy access to Brigtness and Contrast control and amplified stereo audio output.

if you got some time show us some nice pictures

yes please

Almighty made the same setup as I did (Viletim's adpater, with the scaler, here are a few pics. When he gets himself another VGA cable, then he will post some more pics with the SLG 3000 also in line (won't you Almighty? )

http://forum.nozomi.nl/viewtopic.php?f=4&t=3127