RELEASE DESCRIPTION

This release (3.1) of the CGMGen and DrawCGM software differs from 3.0
mainly in bug fixes.  The most prominent of these is that an
incompatibility between CGMGen 3.0 and GPlot 4.2 has been eliminated,
so that CGM files generated by DrawCGM or CGMGen are no longer drawn
very small by GPlot.  This bug may also have shown up as output do
device drivers other than binary and clear text CGM being way too
large.  Text handling has also been improved, so that bugs involved in
passing text strings to DrawCGM (for example on Silicon Graphics
machines) have been eliminated.

	            INTALLATION INSTRUCTIONS

This software is designed to run on VMS systems, and Unix systems 
including UNICOS and Ultrix.  To install the software under VMS,
move all the files (including the GPlot source on which CGMGen
depends) to a single directory.  Edit the descrip.mms file to
include the device drivers and GPlot controllers you want.  Use
the following command to cause VAX MMS to create the DrawCGM library
and the three test routines cgmgen_test.exe, drawcgm_test.exe, and
drawcgm_tst2.exe:

	$ mms 

On Unix systems, move all the files (including the GPlot source on which
CGMGen depends) to one directory.  Edit the Makefile as needed for your
machine and choice of device drivers and controllers;  instructions for
doing so are in the Makefile itself.  The following command will cause
make to create the DrawCGM library and the three test programs listed
above:

	$ make drawcgm tests 

The descrip.mms and Makefile files are also used to make GPlot.
There is also a Makefile in the drawcgm directory which you might
need to edit.

			HINTS

The most trouble-prone part of the current implementation is the
system used to cause pauses at the end of frames when DrawCGM is
used interactively.  In general, if STPAUS has been called, at the
end of each frame (in response to NEWFRM or GRFCLS) the terminal
bell will ring and the program will wait for the user to hit return
before continuing.  This works fine in most cases, but two exceptions
are the following:

	If you are using the X Window System driver, the driver
	will pause at the end of each frame and wait for a mouse 
	click all by itself.  Calling STPAUS will result in a
	second bell and wait after the mouse click.  This is
	a consequence of the way event handling is done in the
	X driver.  When using the X driver, simply don't use
	STPAUS.

	If you are running DrawCGM on the Cray under UNICOS, a
	carriage return is not sufficient to continue at the
	end of a frame.  Use a space followed by a carriage 
	return instead.  This is a consequence of the behavior
	of Cray CFT77 Fortran.