Mouse

 RAT_OFF()      Sets the mouse cursor off
 RAT_LEFTB()    Determines if the left mouse button has been pressed
 RAT_POSIT()    Positions the mouse cursor at row,column coordinates
 RAT_ON()       Sets the mouse cursor on
 RAT_RBHD()     Determines if the mouse right button is currently
                depressed
 RAT_COLL()     Returns mouse column at the last left button press
 RAT_COL()      Current mouse column
 RAT_LBHD()     Determines if the mouse left button is currently depressed
 RAT_EXIST()    Determines if a mouse is available
 RAT_COLR()     Returns mouse column at the last right button press
 RAT_ROWL()     Returns mouse row at the last left button press
 RAT_ROW()      Current mouse row
 RAT_ROWR()     Returns mouse row at the last right button press
 RAT_AREA()     Limits the mouse to a rectangular area of the screen
 RAT_RIGHTB()   Determines if the right mouse button has been pressed
 RAT_RESET()    Resets the mouse to its default values