DEVICE

     DEVICE specifies the graphics device:

	device | name | xsize ; ysize | color type

     The following graphics devices are available:

	XW		X Windows terminal
	PS		PostScript
	NC		NTRANS Computer Graphics Metafile
	GF		GIF file using X-server
	GIF		GIF file not using X-server
	UTF		Universal Transmission Format (AFOS)
	RBK		AWIPS RedBook Graphics
	VG		Vector Graphics (N-AWIPS Product Generation)
	XWP		Combination driver
	FAX		Fax driver
	TIFF		TIFF file

     The following three PostScript device names are included for backward
     compatibility only.  The appropriate settings for the PS device are
     automatically selected based on the information below.

	PS1		PostScript - Landscape / Letter / Monochrome
	PSC		PostScript - Landscape / Letter / 32 Colors
	PSP		PostScript - Portrait  / Letter / 20 Grays

     The XWP driver combines the capabilities of several drivers.  Currently,
     it includes the XW and the PS drivers.  XWP allows the user to display
     graphics to a window, then, without closing the window, a PostScript file
     may be created.

     The UTF driver produces output for AFOS devices and the NAFOS product.
     Note that while both AFOS and NAFOS read files in universal transmission 
     format, the exact file formats for are not compatible.  The default
     output is to an AFOS formatted file.  The color control (see below) is
     used to switch between output types.

     The RBK driver produces output for AWIPS devices and OSO products.  These 
     products are created according to the Standard Formats for Weather Data 
     Exchange format.  However, the OSO format has an extra transmission header
     information section.  The default file is of an OSO format.  The color 
     control (see below) is used to switch between output types.

     The FAX driver produces an NMC 6 bit formatted file. 

     The TIFF driver produces a TIFF file that uses the Group 4 Fax
     compression scheme.  It can also optionally create a file with no
     compression.

     The VG driver produces a GEMPAK Vector Graphics file.  This file can then
     be used in product generation for graphical editing of the elements.
     When producing a VG file, CLEAR has no effect, i.e., all elements are
     added to the output file regardless of the value of CLEAR.

     NAME is the file or window name.  In the NC driver, if the file already
     exists, new frames will be appended to it unless the default file name
     of Nmeta is used.  In this case, the file is overwritten.  The PS driver
     also uses the file name to generate plot files, however no appending is
     attempted.  Files are always overwritten.  In the XW or XWP drivers, up to
     five named windows may be opened.

     If no file/window name is given, the following will be used:

		XWP	GEMPAK
		XW	GEMPAK
		PS	ps.plt
		NC	Nmeta
		GF	gempak.gif
		GIF	gempak.gif
		VG	vgf.vgf
		FAX	999X;0167 (produces the file 999X.6bt)
		UTF	T01
		RBK	T01
		TIFF	AAAA00

		PS1	ps1.plt
		PSC	psc.plt
		PSP	psp.plt

     The UTF driver defaults to an AFOS test product PIL if no entry is given.
     The file name may be the last three characters of a valid PIL, or a full
     file name.  If the file name is a PIL, the product table is read for 
     specific size and time attributes.  If a regular file name is given,
     suitable defaults are chosen for the size and forecast time.  The user
     may also give a base time for the product.  This is added to the file name
     following a semi-colon, i.e., "T01;1200".  This product would have a base
     time of 1200 GMT.  The forecast hour read from the product table is added
     to the base time to give a valid time for the product.

     The RBK driver defaults to an OSO formatted file if no entry is given.
     The file name must be the last three characters of a valid AFOS PIL, or  
     the test PIL id, T01.  The PIL id is used by the product table to find the 
     specific size and time attributes.  The difference between the AWIPS format
     and the OSO format is the information given at the beginning of the file
     and that the AWIPS format does not have any padding of spaces at the end of
     the file.  Similar to the UTF driver, the user may also give a base time 
     for the product.  This is added to the file name following a semi-colon,
     i.e., "93E;311200".  This product would have a base date of the 31st and a 
     base time of 1200 GMT.  The base date may also be given in the full GEMPAK
     date/time format, i.e., "9JH;000931/1200".  The forecast hour read from 
     the product table is added to the base time to give a valid time for the 
     product.  If the base date or time is not specified, then the system date 
     or time will be used for the valid time.  

     The FAX file name entry equates to a wheel and subset for the output 
     product.  Every fax product must have an associated wheel and subset 
     number.  The driver uses the supplied wheel and subset number to determine 
     the dimensions of the product.  These dimensions are defined in the 
     product table, faxprod.tbl.  This file will be named "XXXX.6bt" where 
     XXXX represents the wheel number of the product.  The subset number is 
     embedded in the compressed 6 bit image and is only meaningful to OSO 
     systems that transmit products.

     The TIFF file name entry is the WMO ID of the product.  The driver uses the
     supplied ID to determine the dimensions of the product.  These dimensions 
     are defined in the product table, tiffprod.tbl.  The output file will be 
     named "AAAAII.tiff" where AAAAII represents the 4 character and 2 digit 
     WMO ID of the product.

     XSIZE and YSIZE are the device dimensions.  The specification of their 
     values is a function of the device driver.

     For XW or XWP, xsize and ysize may be (1) the number of pixels in the 
     corresponding direction if the values are specified as integers, or (2) a 
     fraction of the screen size if the values are specfied as reals > 0 and
     < = 1.  

     For the PS driver, xsize and ysize are the paper dimensions in inches.  If 
     xsize is greater than ysize, then a landscape orientation is used.  For 
     xsize less than ysize, the plot orientation is portrait.  

     For UTF driver, xsize and ysize have no meaning, as the dimensions for the 
     display are determined by the entry on the product table (product.tbl) 
     that matches the user supplied pil. 

     For the NC driver, xsize and ysize are fractions of the maximum dimension
     of a NTRANS CGM file.  Their values must be > 0 and < = 1.  If both values
     are less than 1, then the larger value is set to 1 and the smaller value
     is increased proportionally to maintain the aspect value of the user
     input values.
     
     If xsize and ysize are not specified the following defaults will be used:

		XWP	.7;.7	(70 percent of the screen size)
		XW	.7;.7	(70 percent of the screen size)
		PS	11;8.5	(Standard letter size paper in landscape)
		NC	1.0;1.0 (Standard square CGM plotting space)

     COLOR TYPE is a flag for specifying the color scheme to use for the 
     driver.  Currently, only PS will use the color type.  Color type may have
     the following values:

		C		32 Colors
		G		20 Grays
		M		Monochrome lines with color fills

     The default is to use 20 grays.  The exceptions to this are noted below.

     For UTF (which is a monochrome device), a value of C is used to switch the
     output to an NAFOS formatted file.  Any other value for color type results
     in an AFOS formatted file.  

     For RBK (which is a monochrome device), a value of C is used to switch the
     output to an AWIPS formatted file.  Any other value for color type results
     in an OSO formatted file.  

     For TIFF, the default is monochrome output with a white background and all
     graphics drawn in black.  This type of output will be compressed using the
     Group 4 Fax compression scheme.  A value of G will create an output file
     that has a black background with all graphics drawn in white.  It will also
     allow a grayscale image to be written to the output file.  This type of 
     output will not be compressed.

     The GF driver has the same options as the XW driver.  The differences in
     execution are that the GF device will not display a graphics window, and
     will create a separate file for each active frame either when the device 
     is closed or a new file name is given.  The file names are based on the 
     user supplied file name, with the frame number appended to the name after 
     the initial file has been created.  That is, given the default name, the 
     first GF file created will be named "gempak.gf", the following file will 
     be named "gempak.gf.001".