HELP! - Thin vertical scan line scrolling across screen

[freejack_1971]

My MAME cabinet has a 19 inch PC monitor that I turned sideways for vertical oriented games.  The graphics card is an ATI Radeon Xpress 200.  I got the latest version of the ATI Catalyst software to support rotating the display.  I basically made my own version of a vertical 60-in-1 multicade.  I built the cabinet about a year ago, and I'm able to play most games just fine.

My problem is this: When I run horizontally scrolling games like Scramble.  There's a thin vertical line that scrolls/loops across the screen.  It's like's watching a wave ripple in a pond.  It's doesn't make the games unplayable, but it's starting to bug the hell out of me.

Can someone help me out with some suggestions on how to fix this?  I've tried to take snapshots in MAME, but the distortion doesn't show up.  I've tried to change the monitor refresh rates, but I really don't know what I'm doing. 

Any help would be greatly appreciated!

Default VGA monitor
ATI Radeon Xpress 200
768x1024 60hz 
Right 90 degrees

WinXP
MAMEUIhighscore32 0.147

 

[Minwah]

Try turning on triplebuffer in your mame.ini file (or equivalent setting in the UI).

[BadMouth]

That's screen tearing. http://en.wikipedia.org/wiki/Screen_tearing

framesync sometimes cures it.
If framesync alone doesn't, also do triplebuffer

For emulators that don't have a vsync or triple buffer options, you can usually force them using the software that came with the video card.

This could add an input lag of one frame in the game.
Nobody but the most die-hard shmup players would notice it.

[freejack_1971]

Problem fixed!  That was it.  I didn't know that this problem was called "screen tearing", so that's why I was stuck.

I first did waitforvsync and triplebuffer together.  But then I turned triplebuffer off and tried Scramble again.  I didn't notice any difference.

I only played a little bit before leaving for work, so I'll try to get some longer games in later.

Thanks guys!