VGA -> SCART .. solved.

[exiges]

I'm just posting this in case subsequent people can benefit:

For my cab setup, I bought a VGA->SCART cable from Ebay to connect to my Sony PVM 2750 TV/monitor to go from my Radeon 9250.  (The cable was advertised as being specifically for Radeon cards)

Booting the PC with the cable attached, the picture was flickering like hell and unreadable.  Using VNC, from another computer I was able to install Powerstrip, and get some settings that worked, although I wasn't able to get real low resolutions like 240x240 to work.  I had to change the polarity in Powerstrip to "positive", and select "composite sync".  Overscan was quite an issue to in NTSC refresh rates.  (And naturally any resolution over 288 had to be interlaced)

This seemed to work "acceptably", but if the machine failed to finish booting properly (and therefore powerstrip not starting) then there was no way I could see what was going on on the screen to debug it.. meaning I had to open up the cab, pull out the PC, fetch another monitor from somewhere and connect it up.. not ideal.

Time for an ArcadeVGA card then...

The ArcadeVGA card arrived yesterday, and according to most reports, it's just a plug and play affair (once drivers are installed) and the boot screen should come up clearly.  It didn't.. I still had annoying strobing/flickering (the picture was the right size, and was static horizontally, it just flickered vertically) which seemed to suggest a V/Sync issue.

Sure, I could use Powerstrip to just apply "Composite Sync/Positive" settings to it, and I had access to the low resolutions 240x240, which was good.. but not ideal.

After much head scratching it seems that my TV/monitor wouldn't sync to the signal it's receiving and from what I'd gathered using Powerstrip, a "composite sync" was needed.

Maybe the instructions out there are easy to find, but it took me a while and took some deduction/guessing rather than explicit instructions.

So I opened up the VGA end of my cable and saw that only the H/Sync wire was attached

If you view it from the solder/wire end, it's this pin


   
  / - - X - - \
 /  - - - - -  \
/   - - - - -   \

I got my soldering iron out and made a join between that pin (13) and the one to the right of it (pin 14)


  / - - X Y - \
 /  - - - - -  \
/   - - - - -   \

Et voila.. the picture stabilised and it looks sweet as a nut.. and the boot screen shows up perfectly too, and games show as crisp as anything.

Me = happy.