.TH MARS 1 5/20/84
.CM 3
.SH NAME
mars \- memory array
.IR redcode (1)
simulator
.SH SYNOPSIS
mars [-dfhmp] [-cqs<value>]
.I 
file1 file2 ...
.SH DESCRIPTION
.PP
.I mars
is a simulator for the 
.I redcode
machine specified by Dr. Kee Dewdney in the
"Computer Recreations" column in the May 1984 issue of
.I Scientific American. 
The command line contains any arguments followed by a list of object
code file names.  The easiest way to create an object file is to use
the 
.IR redcode (1)
command to a assemble the object file from a redcode
source file.
.SH OBJECT FILES
.PP
An object file contains three header lines indicating the name of the
program, the length of the program, and the offset from the beginning
of the starting location.
Here is a sample redcode object file, for 
the Dwarf program:
.sp
	name dwarf
.br
	length 4
.br
	start 1
.br
	00000007999
.br
	20000517999
.br
	10000027998
.br
	41799800000
.SH INSTRUCTION FORMAT
The instruction format is an 11 digit decimal string, as follows:
.sp
	0	1	2-5	6	7-10
.br
	+-------+-------+-------+-------+-------+
.br
	|opcode |mode1	|arg1	|mode2	|arg2	|
.br
	+-------+-------+-------+-------+-------+
.SH OPTIONS
.PP
Options allow for tracing execution, for graphically displaying the
progress of each program, and for analyzing and dumping memory before
and after execution.  For example, the following command:
.sp
	mars -s1234 -f -c20000 dwarf.obj gemini.obj imp.obj
.sp
specifies that imp, dwarf, and gemini are to be run together, with a
fullscreen display for 20000 cycles using a random number seed of 1234.
.TP
.B -cN
.I 
cycles
option, determines the maximum number of cycles for this run.
The default is 10000.
.TP
.B -d
.I 
debug
option, causes the execution to be traced in excrutiating detail.
.TP
.B -f
.I 
fullscreen
option, causes the execution to be displayed graphically on any
terminal supported by
.IR curses (3).
.TP
.B -h
.I 
holes
option, causes a description of memory usage to be printed after
execution terminates.
.TP
.B -m
.I 
memory dump
option, causes memory to be dumped before and after execution terminates.
.TP
.B -p
.I 
procedure dump
option, similar to 
.B -m
option, except only memory near each program counter is dumped.
.TP
.B -qN
.I 
quit
option, indicates the minimum number of programs required to be alive.
For example, if
.B -q3
is specified, execution terminates as soon as there are fewer than
three programs still alive.
.B -q1
specifies that execution continues as long as any program is alive.
The default is to quit when there is but one program still running.
.TP
.B -sN
.I 
random seed
option, specifies a random seed for this run.  The default is 0 (i.e.
a random seed based on the time).
.SH SEE ALSO
redcode(1)
.SH BUGS
None known.
.SH HISTORY
.TP
20-May-84 Michael Mauldin (mlm) at CMU
Created.