
If you are reading this, you are probably interested in modifying
STARTREK to run on a different system. These meager comments may help.


The CVL  version  of  startrek  expects  to  be  used  on  a
DATAMEDIA  Elite  2000  terminal.   The  source  code may be
modified to run on other CRT terminals  with  direct  cursor
addressing by changing the terminal control functions in the
file term.c .  Extensive modifications  would  be  necessary
for use on a hard copy terminal.

There is also a color graphics  version  for  use  with  the
Grinnell  Image  System.   This version can be produced from
the source code in the files gmain.c, gmove.c, gio.c,
gutil.c, and term.c which correspond to the standard source.
The graphics routines are in the file grin.c. They could
conceivably  be  changed  to  run on other graphics systems.

The Startrek program use EMPTY system calls to determine if
the standard input is empty or not. If it is not empty, this
means that a command is pending so some of the display
refresh  is skipped to make response faster.  If STARTREK is
to be used in a system with the empty call, all references
to empty must be removed from the code in io.c .

The real time feature which allows the enemy to attack and
consumes stardates if you take to long between commands also
uses the empty call. To eliminate this, delete the parameter
REALTIME from the file param.

There is a debug option; command -1  causes invisible things
to be shown and overrides damage to the scanners.
This option requires a password which you can find in the code.

FILES
     The source code is divided into several files  according  to
     functional groups. There are also some auxilliary files.

     comp      shell file which compiles Startrek, messages to comp.out

     main.c    the main program - reads commands and calls
	       various functions to do the required action

     param     standard set of parameters, defines various system
               values

     extern    external  variable  definitions,   used   in   all
               following sections

     move.c    functions concerned with moving and firing weapons

     util.c    general purpose  functions  such  as  random  number
               generators

     io.c      input/output routines, not terminal dependent

     term.c    terminal specific code such as cursor  addressing,
	       screen clear, etc. must be modified for terminals
	       other than Datamedia Elite 2000.

     grinnell  directory with code for Grinnell graphics version

MORE
     For further information, contact

		Robert Haar
		Computer Vision Lab
		Computer Science Center
		University of Maryland
		College Park, Md. 20740
