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\centerline{\bf New GPLOT on the System}
\bigskip
A new version of GPLOT has been installed on the front ends with
several changes in organisation. There has been more interest from
remote sites in receiving the software and running the program at their
end than was originally expected, and also strong interest in adding
device drivers. In fact, given the possibility of network problems
during long interactive sessions, this may be the most efficient mode of
use. To facilitate this we have made some reorganisation of the code
and applied some lessons learned from earlier releases.
We have worked to make GPLOT capable of compiling and running on
both UNIX and VMS and have added drivers for the X-window system 
(version 11) and the SUN workstation.

Clear text CGM files can now be both generated and interpreted by
GPLOT, allowing the editing of a CGM representation.

This would seem like a reasonable time to clarify some of the
components of GPLOT and their purpose for those who will be running it
remotely. It should be reiterated that the purpose of GPLOT is to take
a CGM (Computer Graphics Metafile) file and create the require pictures
on the output device by means of a driver. The CGM is an ANSI and ISO
standard and is our normal graphics metafile.

All of the code is available in the TEX\$ROOT:[GPLOT] directory on the
front ends, including drivers which are not installed  in that
executable image. Here is a quick rundown of the code modules involved.

\noindent DEFS.H---Common definitions for the modules.

\noindent CCDEFS.H---Common definitions for clear text modules.

\noindent GPLOT.C---A small controlling module.

\noindent CGM.C---Contains the CGM-specific (binary format) information.

\noindent CCGM.C---Contains the CGM-specific (clear text) information.

\noindent IO.C---I/O routines.

\noindent UTILS.C---Utility routines used by the code.

\noindent PKRAS.C---Module to decode \TeX-style PK raster font files,
used for devices that do not have good firmware fonts.

\noindent DEVICES.C---Decides which device module to invoke, the only
piece of existing code that needs to be changed when adding a device
(about 3 lines).

\noindent GPT_COMMANDS.CLD---Parses the command line under VMS.

\medskip
\noindent Then there are the device driver modules.
\medskip

\noindent PS.C---Postscript module.

\noindent TEK.C---Tektronix module.

\noindent GKS.C---Graphical Kernel System for VAX-VMS (requires GKSDEFS.H)

\noindent UIS.C---Driver for the VMS workstation software

\noindent PERITEK.C---The frame buffer that we use to make animations.

\noindent CGMB.C---Binary format CGM driver.

\noindent CGMC.C---Clear text CGM driver.

\noindent XWS*.C---The X-windows system driver (requires XWS*.H)

\noindent SUNDRIV.C---SUN workstation driver.

\medskip
There are some utilities available for raster operations in the files 
CARRAY.C and DRVCLA.C.
\medskip
\noindent Controllers---These are devices that GPLOT looks to for
synchronisation of its output, there are presently only two.

\noindent TTY.C---Terminal controller, GPLOT will look to the terminal
input for synchronisation.

\noindent DQ.C---DiaQuest controller, GPLOT will use a DiaqUest to
allow the frame-by-frame laying down of video output on an editing
video tape recorder. This would be in combination with the Peritek
driver in our animation system.

\medskip
\noindent Text operation. The GTEX processor reads DVI files created by
the \TeX\ system and has specific modules GTEX.C and CACHE.C.
It is not required for the GPLOT system, and neither it nor the software
fonts are available yet under UNIX. 
\medskip
\noindent Fonts; software fonts in the PK (packed raster) format are
used by GTEX and (sometimes) by GPLOT, the raster images are contained
in the files TEX\$PK:[mag]*.PK where ``mag'' is the integer
magnification normalised to 1000 for a ten-point font at 300
pixels/inch resolution. In order to have the logical defined for
this directory you presently must have ``@TEX\$INIT'' in your LOGIN.COM file.

\medskip
\noindent Tools to help build the system. The DESCRIP.MMS file is standard
input file for the VMS MMS utility; it should be noted that if not all
of the drivers are to be linked then the corresponding preprocessor
constants are not defined during the compilation of DEVICES.C, details
are in the DEVICES.C file.
If you do not have MMS the MAKEGPLOT.COM file will also build the
system from sources. 

\noindent For UNIX sites there is a MAKEFILE for the standard MAKE utility.

\noindent Operating system independence is achieved via precompiler ``IFDEF''
statements. 

\noindent The GPLOT\_INSTALL.DOC file contains information to help
installers, and there are a few .HLP files.


\noindent Examples---EXAMPLE\_1.CGM, MDIBF2.CGM, SMPL07.CGM, and TG1BF2.CGM
are example CGM files and DEMO.TEX is a \TeX\ file that exhibits how
GTEX can combine individual frames from several files on one page.

\medskip
FTP access---All of these files are available on our front end
machines, internet addresses cpwscb.psc.edu and cpwsca.psc.edu in
directory tex$root:[gplot] via DECNET or ftp (anonymous login by user
anonymous, password anonymous).
Since FTP connections to the front ends are
sometimes troublesome we will also provide these files on our HARRIS
UNIX machine, GODOT (internet address GODOT.PSC.EDU), via anonymous
FTP in directory /gplot. Users should give their name as the password.
\bye