1 SHOW

	This procedure allows control of display parameters used
    by the MAPPING plotting package

2 FIRST
	(integer)

	First channel to be plotted.

2 LAST 
	(integer)

	Last channel to be plotted.

2 SIZE
	(real)

	Size of the area to be plotted (in arcseconds).

2 SPACING
	(real)

	Contour step (in map units). If 0, contour levels will be
	adjusted automatically according to the min and max of the image.
	If -1, the contour levels provided by the user (command
	LEVELS) will be used.
	
2 CROSS
	(real)

	Size of the cross drawn at map center (in arcseconds). If 0,
	no cross is drawn.

2 MARK
	(character)

	Type of marking for each channel map. Possibilities are
	CHANNEL VELOCITY FREQUENCY or NONE
	
2 BEAM_TYPE
	(character)

	Type of beam plotted in addition to the image. Possibilities
	are DIRTY CLEAN or NONE. 

2 EXTRA
	(character)

	Additional data plotted. Current possibilities only include
	UV coverage (COVERAGE) or NONE.

2 DO_HEADER
	(logical)

	Draw header in addition to map.

2 DO_NICE
	(logical)

	Plot clean beam in each channel map.

2 DO_BIT
	(logical)

	Plot bitmap for each channel map.

2 DO_CONTOUR
	(logical)

	Draw contours for each channel map.

2 DO_GREY
	(logical)

	Use color-filled contours rather than simple contour lines.

2 DO_TREE
	(logical)

	Create a separate plot directory for each channel. This can be
	useful for further additions to the plot.