Losing V-sync for some resolutions- Help!

[pacman]

Here is my config :

Arcade VGA + Jpac+Jamma
Monitor Hantarex MCT9110 + capkit
Mamewah Frontend running at 640x480
Mame 0.93 command line
Ini's generated with AVRES (only 60 hrz option enabled)

Everything is running fine and all games are launched in the correct native resolution or close to it but there is an issue: For games using low resolutions (240x240, 256x240) I cannot have the V-sync stable and games rolls quite fast. If I adjust the v-pot then consequently I will lose the V-sync for the other games.

All vertical games runs fine and stable whenever the game is stretched or not, I just have this damn rolling for low resolution on some Horizontal games.

Do you know guys what to do? Is there a setting in mame to finetune this and solve the problem? I am really desperate

[RayB]

First, I don't think your AVRES ini's are being used. As far as I understand (correct me if Im wrong people) is that you are losing vsync due to modes using lower than 60hz. For example, I bet it happens to you with Pacman games and Mortal Kombat? Those games use something like 53hz.

By very very carefully tweaking it should be possible to stablize the picture in both modes. It's called the "sweet spot" where the poteniometer knob is adjust just enough to hold vertical for both modes.

Let us know if this helps.

PS: Are you sure you're using the WINDOWS command line version and not DOS? The DOS version doesn't support individual INI files. That's why it would be ignoring the INIs.

[pacman]

Hi RayB

Thanks for your reply on this. Well I am sure using the Mame Window command line and not DOS so I am pretty sure my INI files are used by Mame; Pacman is a Vertical game and it runs fine and stable. For example I have noticed that Ghost and Goblins rolls quite fast as the game use a very low resolution at 60hrz. It can be also an issue with the v-pot as I have noticed it is very sensitive.If I put jsut my finger on it then the cab goes out of sync quit easily...maybe I need to repalce it.

[RayB]

vpot sensitivity could be normal. I use a Happ Vision Pro II which I bought brand new, and it requires barely touching the pot to affect it.

If your pot is old and dirty, that could affect it.