INT 33h,  0Eh (14)       Light Pen Emulation Mode Off

    Switch Light Pen Emulation OFF in BASIC.

       On entry:      AX         0Eh

       Returns:       Nothing

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    Function 0Eh disables the light pen emulation in BASIC. When the light
    pen emulation is disabled, cxalls to the PEN function return information
    about the light pen only.