- ScreenScrollXPos = Stretch * (MurphyScreenXPos + TILEX / 2) - ax;
- ScreenScrollYPos = Stretch * (MurphyScreenYPos + TILEY / 2) - Ay;
+ ScreenScrollXPos = (MurphyScreenXPos + TILEX / 2) - ax;
+ ScreenScrollYPos = (MurphyScreenYPos + TILEY / 2) - ay;