Screen Shift Problem with 3dfx board

I have a problem with 3dfx board; every opengl program I try to run is shifted roughly by one third down, which means that the lower third is down off the screen.
I am using a Voodoo2 board with the latest opengl32.dll and windows 95.
Is there a setting which I have forgotten ?

Thanks in advance


I assume you are running the application in a full screen mode. This “shifting” occurs because of the variance in the signals sent to your monitor for a different resolution. Try adjusting your monitor to move the display up and position it in the center of the screen.

If this fails, grab the latest monitor .inf from you monitor vendor or OEM where it was purchased.

Does that address your concern, or am I off base in my assumtion of the problem?


I don’t know. Some application and games, running in OpenGL (Quake, or Quake2) do work all right and there is no shift.
The resolution problem could be something I have to look at, though.
What you say is that the OpenGL program I am trying to run is using a higher resolution than the screen has. My only thought, right now is that if this happened then there would also be a lateral shift, whereas there is only a shift down.
I’ ll check. Thanks. If anybody has other ideas …

You are right about resolution. If I put my screen at 640x480 then the OpenGL image is allright; at 800x600 the shift is of about 1/3, at 1024x768 is about 1/2.
The 3dfx board is set at 640x480.
NOw, I suppose I have to look at the calls that govern resolution …

This isn’t something you affect in code (at least you shouldn’t address it that way). Adjust your monitor to move the display area up (while in one of those modes).

It has to do with the vertical and horizontal frequency that display mode is using. After adjusting your monitor, the settings should even after subsequent reboots.