MOUSEINFO

typedef struct {
    byte msExist;      // TRUE if mouse exists, FALSE otherwise
    byte msRelative;   // see below
    word msNumButtons; // number of buttons on mouse
    word msRate;       // see below 
    word msXThreshold; // horizontal threshold before acceleration
    word msYThreshold; // vertical threshold before acceleration
    word msXRes;       // horizontal resolution
    word msYRes;       // vertical resolution
} MOUSEINFO;

Contains information about the mouse, such as the type of coordinates and the number of buttons.

msRelative

Mouse-coordinate flag. It is 0 if the mouse returns absolute coordinates, or 1 if it returns relative coordinates.

msRate

Maximum number of hardware interrupts, per second, that the mouse can generate.