Voodoo/NVDA inconsistencies

I’m lost here, I’ve got this little program that for some reason can’t draw 2d dots to certain vertical lines in my window on a Voodoo 3 card. Another pc with a GeForce2 card runs the program just fine and can draw anywhere in the window.

The pattern of vertical lines on the Voodoo 3’s window makes me think the dot coordinates are being scaled somehow. For example, drawing point(300, 300) and point(301, 300) will produce one dot at (300, 300) because the second one drew over the first. But point(299,300) and point(300,300) will get along just fine.

Changing the width parameter in gluOrtho2D() is the only way to alter the pattern of untouchable vertical lines. This is giving me a headache, what can I do?

void myInit(void)
glClearColor(1.0, 0.0, 0.0, 0.0); glColor3f(0.0f, 0.5, 0.75f); glPointSize(1); glMatrixMode(GL_PROJECTION);

void point(glint x, glint y)
glVertex2i(x, y);

You can try glsetup or download the latest driver direct from 3dfx.

I thought that might help too, but there was no change after running glsetup.