Diy Vga to scart lead to use with 60 in 1 jamma board?

Damien King

Hi folks,

I've just got my hands on a 60 in 1 jamma multiboard and shall be making a little cocktail cabinet with screen flipping.

I want to go for an authentic look with this so am going to go down the crt route as the space will be there for it.

The board has a vga socket so the plan was to get hold of a really old crt monitor (with a nice curved screen) to use. I cant find one for love nor money at the moment.

I have a couple of 14inch crt portable tvs that i keep handy in case I want to fire up an old console from time to time. they have that nice screen curve i'm after and would happily use one on this project.

The gameboard has Dip switches to select between GGA - 15.75Khz and VGA - 31.5 Khz.

Ive had a quick look at pinouts but thought I'd pick your brains first before I go snipping, soldering and swearing.

So my question is this, can a diy VGA to Scart be done and more importantly, will it work?

The Last Bandit

VGA to SCART cable won't work - VGA refresh frequency is 31KHz, SCART is 15KHz.

Use the video from the Jamma edge to drive the TV instead. Look up Jamma to SCART cables for all the gory details.

CathalDublin

As above.
You don't go from the vga to scart just go from the jamma harness/fingerboard(R,G,B,Sync,Ground) to the scart on the TV and set the board to 15Khz

Here's a couple of easy to follow diagrams, you wont even need to solder if you cut a scart cable and use a meter to check what wires to what pins.
It will technically work without the resistors in the first diagram.

I'll have a look in my parts "collection" and see if i have the stuff to make an adapter,pritty sure i do.

The Last Bandit

BrownFinger wrote: »

I'll have a look in my parts "collection" and see if i have the stuff to make an adapter,pritty sure i do.

Fairly sure I do as well.. They're called Superguns

Well Its just an edge connector and a butchered scart cable!

The Last Bandit

BrownFinger wrote: »

Well Its just an edge connector and a butchered scart cable!

Don't be giving away my secrets!!

Damien King

Thanks for the replies folks,

As I have a fully wired jamma harness I should just be able to snip off the arcade monitor 5 pin molexy type connector and solder these wires up to a scart connector, with video sync and ground going to scart pins 18 and 20,

I'm assuming scart pins 4, 6, 8 and 16 are for Audio with pins 8 and 16 having the mono output bridged between the scart Left and Right audio?

This might actually be less of a balls to do than I thought, Now to tackle getting the TV to come out of standby while fitted in a cocktail cabinet. Shouldn't be to much haslle as older TVs have the advantage of having proper switches that you can actually de solder and re wire without the use of a microscope...

Although Its a certainty a proper old arcade monitor will become available just as the soldering iron is cooling down.

many thanks for the advice folks

CathalDublin

You should be able to supply power to the scart socket to make it change to the correct channel and come out of standby automatically, let me see if I can find a diagram

OK found it, this worked on one of my TVs and not the other, I just pulled the +5 and +12 from my jamma PSU, some TVs have a secret service menu which you can enable some options in and adjust horizontal/vertical sizes too.

The Last Bandit

Damien King wrote: »

I'm assuming scart pins 4, 6, 8 and 16 are for Audio with pins 8 and 16 having the mono output bridged between the scart Left and Right audio?

SCART Pins 2 and 6 are for audio Left and Right, use the 3.5mm Lineout jack of the 60-in-1 to drive this otherwise you need to attenuate the audio coming off the Jamma edge as it'll be too loud for the TVs input.

SCART Pin 8 needs 12V to select the AV channel and set 4:3 mode

SCART Pin 16 needs 3V to select RGB mode