MSCZERO

	? - print this help
  <space> - print coordinate at cursor position
	c - center and print coordinate (*)
	e - edit the coordinate of a marked object from a coordinate list (*)
	i - Toggle queries for coordinate ID in 'w' and 'x'
	m - mark coordinates from a list of celestial coordinates
	r - redisplay
	s - select nearest marked object
	u - get and mark USNO coordinates
	w - write coordinate and ID at cursor position to log file (*)
	x - center and write coordinate and ID to log file (*)
	z - center, get new coordinate, set zero point offset (*)

	n - go to next mosaic exposure
	p - go to previous mosaic exposure
	q - quit

(*) The final coordinate will be marked on the display if the "mark" parameter
    is set.


e   The nearest coordinate from last marked coordinate list (marked with
    'm') is selected.  The cursor is used to define a new coordinate based on
    the current coordinate system.  This coordinate may be centroided if
    the 'c' key is used.  The coordinate list is updated, after a query,
    when that list or a new list is marked, when the image is changed, or
    when quiting.

m   A query is made for a coordinate filename.  If the file exists the
    coordinates are marked using MSCTVMARK.  You are queried for the
    radius of the circles to be drawn, the gray level (the color where
    red=204, green=205, blue=206, yellow=207, cyan=208, and magenta=209),
    and whether to draw labels.  Other marking parameters, such as the
    fields giving the RA, DEC, and ID, are part of the task parameters.

s   Select the nearest marked coordinate.  If no coordinates have been
    marked a warning is printed otherwise the RA, DEC, and ID are
    printed.  The selected coordinate becomes the default for the 'z'
    key and the selected ID becomes the default for the 'w' and 'x' keys
    when the ID query mode is enabled.

u   A query is made for a coordinate filename.  This is the file that will be
    created if it does not exist.  If an existing file is specified (such
    as that from a previous use of the 'u' key) you are asked if the
    file should be deleted.  If the file is not deleted then it is simply
    used to mark without getting new coordinates.  This useful for
    remarking after redisplaying or modifying the coordinate zero point.
    If the file is deleted or does not exist an internet catalog is
    accessed using MSCGETCATALOG with the queried magnitude limit.
    Finally the objects are marked with MSCTVMARK as described for the
    'm' key.  The labels are the magnitudes.

z   The position of the cursor is adjusted by centroiding and the coordinate
    based on the current coordinate system is determined and printed.  You
    are queried for a new RA and DEC with the default either being the
    estimated position (the first time), the last entered position, or the
    coordinate from the last select ('s') command.  The difference between
    the estimated and entered coordinates is used to adjust the zeropoint.
    All further coordinates derived or marked from a coordinate list will
    use the new zeropoint.  The zeropoint adjustments are done internally
    and do not change the data header until quiting or going to another
    image.