NAME
    VBeamPos -- Get vertical beam position at this instant.

SYNOPSIS
    pos = VBeamPos()
     d0

    LONG VBeamPos( void );

FUNCTION
    Get the vertical beam position from the hardware.

INPUTS
    none

RESULT
    interrogates hardware for beam position and returns value.
    valid results in are the range of 0-511.
    Because of multitasking, the actual value returned may have
    no use. If you are the highest priority task then the value
    returned should be close, within 1 line.

BUGS

SEE ALSO