Res issues, Sony TV hack

[boardjunkie]

Ok, I just got done hacking a flat face Sony Trinitron to accept RGB inputs.....that was the easy part. It looks simply....stunning with one exception (not the tv's fault). Everything works fine (as it did on a real arcade monitor), but the flicker is so bad it made it hard to look at. At a res setting of 320x240 the flicker is gone and everything looks good. But the MameUI window is only showing a small portion of it, making it useless. I tried installing Maximus, but even at the lowest res setting it offered there wasn't enough of it displayed to get the whole pix(selection/options screens, games are fine). Am I overlooking something?

I started with a setting of 640x480, which was fine save for that damn flicker.

So how you's guys doin' this?

[ahofle]

The flicker is because you are running an interlaced resolution (640x480i).  When you go back down to 320x240, you are no longer interlaced.  There are plenty of frontends that run at CGA resolutions out there.  You definitely don't want MAMEUI as it's not really a true front end and as you've discovered is useless at low resolutions.

[MonMotha]

Depending on how you did your hack, the TV may no longer be able to handle interlaced inputs properly.  If you attempt to display an interlaced input as though it were progressive, it will appear VERY flickery, especially with lots of hard lines as are common in computer graphics.  How are you inputting sync to the TV?

Even if it is able to handle interlaced signals properly, it'll always appear flickery, as ahofle indicated, especially again on computer graphics.  This is just the nature of interlaced inputs.  If the TV happens to support 480p, you could run it at that resolution (which is "VGA"), but I don't know that any of the Trinitron TV sets supported this.

[boardjunkie]

http://forum.arcadecontrols.com/index.php?topic=110119.0

[MonMotha]

Your simple sync combiner circuit may be distorting the sync signals such that the TV can't figure out that it's supposed to be interlaced, especially since that input would normally expect CVBS on that input.  Is there a better place you can inject sync signals?  Ideally at TTL levels and maybe even separate rather than composite?

[boardjunkie]

It looks exactly the same on an arcade monitor, so I don't think the sync is an issue. It boils down to a resolution deal.......it looks great at 320x240. I just need to spend more time with MaLa to get it set up right. I made some progress yesterday, but didn't have a lot of time to screw with it.

[MonMotha]

Well, if you're seeing this on your arcade monitor, as well as the TV, then it's just due to the interlace.  Some people are more sensitive to it than others.  I can see it, and progressive scan looks a lot better, but it's not overly objectionable to me.

[boardjunkie]

Its fine at the lower res (320x240). It looks pretty impressive, but I need to build a more sophisticated video amp to have better control over the image appearance.

[Jack Burton]

If you wanted to you could flat out run windows in 640x240.  I used to do this with my little PVM.  It was serviceable for a simple setup.  

Technically you should be able to get away with 800x300 on this monitor.