COMMENT ⊗   VALID 00004 PAGES
C REC  PAGE   DESCRIPTION
C00001 00001
C00002 00002				   HOW TO USE "SPACEWAR"
C00008 00003			  CONTROL BUTTONS AND OTHER PHYSICAL LAWS
C00029 00004				    RUN-TIME PARAMETERS
C00036 ENDMK
C⊗;
			   HOW TO USE "SPACEWAR"

Anyone who needs to be  told what SPACEWAR is,  has no business playing  it.
This file will concentrate on the specifics of using SWR here at SAIL.

To get started, R SWR.  You'll be asked for certain parameters, as follows:

	HOW MANY SHIPS?

The current limit is 5 ships.  Since quite often some of the control buttons
are inoperative (or just  plain missing), it is  sometimes necessary to  ask
for more ships than you need just to get enough working ships.

	KEYBOARD BUTTONS?

There are two sets  of buttons hooked directly  into the system.  The  other
buttons (up to three sets, though often only two are connected) are  plugged
in behind the terminal and are called "keyboard buttons" (because they  work
by turning on bits  in the keyboard  input line).  If  you are playing  with
fewer than  3 ships,  you have  the  option of  using the  keyboard  buttons
instead of the other sets.  The usual criterion for deciding which to use is
the current condition of the various  button boxes (i.e., which ones  happen
to be working these days).

	TYPE Y TO GET A STANDARD GAME

The standard game  is described prior  to the above  question.  It  includes
selections from most of the options  below.  If it's exactly what you  want,
good for you.  Otherwise type N and proceed.

	SECOND CONSOLE?

You can have the display put on  two different III's, in case you have  more
people than will fit around one screen.   The console number is the "TTY  #"
shown above the screen, and should be in the range 20 to 25.

	HOW MANY SPACE-MINES?

See next page for a description of space-mines.

	PARTIAL DAMAGE?

See next page for a description of partial damage.

	DISPLAY SCORES?

If requested, the scores are displayed around the edge of the screen.

	TWO TORPEDO TUBES?

The alternative is a single tube per ship.  Each tube takes a certain length
of time to reload (the same time for both tubes), so having two tubes  means
you can get off two shots before having to wait.  It is somewhat  surprising
how different the flavor of  the game can be  depending on whether you  have
one or two tubes.

	TEAM SCORES?

This is asked only if you have  exactly 4 players.  With team scoring,  only
two scores are  displayed, each  of them  being for  a pair  of ships.   (In
general, the best way to determine which score is yours is by observing when
it changes.)  Also, if there  are two surviving ships,  and they are on  the
same team, it is counted as a win and a new round is begun.

	KILLER SCORE?

Under normal scoring, you get one point  for being the sole survivor at  the
end of a round.   This is also  true under killer  scoring, but with  killer
scoring you also get a  point for each ship you  kill and lose a point  each
time you get  killed.  (Note  that getting hit  by your  own torpedo  breaks
even.)

	HYPERSPACE?

See next page for a description of hyperspace.

	ACTIVE DRONES?

See next page for a description of drones.

	"RANDOM" STARTING POSITIONS?

If you don't choose random starting  positions, each ship will start at  the
same place each time, and these places will be equally spaced around the sun
at a fixed distance,  with the ships pointing  toward the sun.  With  random
starting positions, the distance  from the sun is  unchanged, but each  ship
starts at  a randomly  selected position  around the  sun, and  in a  random
orientation.  These positions/orientations change each round.


Having answered all these fool questions, you will now see the screen  clear
and the countdown begin for the first round.  The details of play are  given
on the next page.
		  CONTROL BUTTONS AND OTHER PHYSICAL LAWS

Each ship  is  controlled by  a  set of  four  buttons, known  as  "spacewar
buttons".  As noted on the preceding page (under KEYBOARD BUTTONS), two sets
are hooked directly into the system.  If  you wish to use the other  buttons
(as you must if  you are playing  with more than  two ships), these  buttons
must be hooked up to the screen you  wish to use.  See a wizard if you  need
to move  the buttons;  otherwise you'll  have to  use the  screen where  the
buttons happen to be.

For each ship, the button nearest the cord leading into the box is the  FIRE
button.  Pressing it causes  a torpedo to  be fired if  that ship's tube  is
loaded.  Each ship has either one or two tubes (see parameter description on
previous page).  If you hold the fire button continuously, you'll note there
is a "latency  period" between the  two tubes' firing;  this latency  period
tends to  be about  right for  bracketing an  enemy ship.   After each  tube
fires, there  is a  "reload delay"  before it  can be  fired again.   It  is
generally poor strategy to  fire continuously, since  you may find  yourself
unable to fire  at a crucial  moment.  There is  also a limit  on the  total
number of torpedoes each  ship may fire, but  this limit is rarely  reached.
When a ship has a torpedo ready to fire, there will be a bright spot at  the
center of the ship to indicate the tube is loaded.

The next button after the fire button is THRUST.  Pressing it causes a flame
to extrude from the  base of your ship,  indicating that it is  accelerating
forward.  It being an acceleration, it is cumulative.  You cannot run out of
fuel.

The remaining two buttons are ROTATION.  They cause your ship to pivot about
its center.  The buttons are not always  wired up the same, so the best  way
to determine which  button is which  direction for your  ship is by  testing
them.  The rotation is at a fixed velocity; when you release the button  you
stop rotating.

HYPERSPACE

If you  have elected  to  play using  hyperspace,  then pressing  both  turn
buttons simultaneously will cause your ship to go into hyperspace.  The ship
disappears from the screen, and reappears some time later (the time  varies)
in a random position.  This random position may be right next to the sun, in
which case about the only  thing you can do is  go back into hyperspace  (if
you're quick  enough!).   Just before  the  ship reappears,  a  particularly
bright star will appear  at the spot of  its impending arrival, giving  that
player a chance to prepare for the reappearance, as well as giving the other
ships a chance to lob a few shots  that way.  There is also a chance that  a
ship which enters hyperspace will explode immediately upon returning.   This
probability increases  for  any  given  ship  each  time  that  ship  enters
hyperspace.  You pays your money and you takes your chances.

GRAVITY

The sun is located at  the center of the screen,  and is the only source  of
gravity.   Torpedoes  currently  use  an  inertialess  drive  and  are  thus
unaffected by gravity (one of these days this may become an option).   Ships
and space-mines (see below) are affected by gravity and thus have a tendency
to fall into the sun.  Mines usually start out in safe orbits; ships are not
so lucky.  You will find that, in general, you do not have enough thrust  to
escape the sun at the beginning of the game.  You must therefore  accelerate
toward the sun in  some sort of cometary  orbit, then accelerate away  after
passing it.  This will give you enough velocity to roam about at will  (more
or less) for  a while.  [Note:   Experts can ignore  these general hints  at
strategy.]  If you get too close to the sun, your ship will be destroyed  in
a flash of light.  The  more velocity you have, the  closer you can pass  to
the sun without getting killed.

STRUCTURE OF THE UNIVERSE

Anything which  reaches the  edge of  the  universe (i.e.  the edge  of  the
screen) "wraps  around" to  the opposite  edge.  This  can get  particularly
confusing near the  corners, which in  fact act  as a single  point.  It  is
possible (and nasty!)  to shoot torpedoes  through the edge  of the  screen.
It's tricky trying  to aim  such shots, but  it can  be done with  a bit  of
practice.  Whether or not  you can aim  this way, you  should watch out  for
other people who can!

INCENDIARIES

There are two kinds of explosive which you have to watch for.  The first  is
torpedoes.  This includes your own; usually your shots will fade out  before
they can wrap around the screen and  strike you, but if your course  changes
due to passing by the  sun it is possible to  shoot yourself.  You can  also
shoot yourself by firing while moving  backward at high speeds, because  the
torpedo's initial velocity will  not counteract your  speed and the  torpedo
will thus be  moving in the  same direction as  you.  In general,  torpedoes
leave the nose of a ship with an initial velocity (note velocity, not speed;
we're talking  vectors) which  is that  of the  ship plus  a fixed  constant
directed forward from the nose.  It is sometimes possible to fire a  torpedo
while your ship has  a velocity roughly negative  that of the torpedo,  such
that the torpedo is practically  motionless.  Such shots are very  difficult
to detect.   Remember  also that  torpedoes  are not  affected  by  gravity.
Torpedoes fade out after a time;  they become slightly brighter just  before
they do, as a warning.   They do not disappear if  the ship that fired  them
gets killed.  Thus it  is possible for  you to kill  someone even after  you
yourself are destroyed.  (In the vernacular, such a shot is known as a "hand
from the  grave".)  One  final note:   It is  possible to  shoot down  other
torpedoes.

The other kind of  explosive is space-mines.  These  are bright blobs  which
float about  the screen  and generally  get  in the  way.  Their  motion  is
controlled by nothing but  gravity.  If you  run into one,  it and you  will
blow up.  You can  also destroy a  mine by hitting it  with a torpedo.   Two
mines which collide will destroy each other, and a mine which falls into the
sun will also be destroyed.  (It is not possible to destroy the sun.)  These
last two events are somewhat rare.

In the case of both torpedoes and  mines, there is a certain region of  your
ship which is the "target area".   While the ships are drawn differently  to
enable you to tell them about, the  target areas are the same for  everyone.
A hit on the "body" of the ship (the cigar-shaped section running lengthwise
down the  middle) is  always fatal;  a hit  on the  "fins" (actually,  on  a
standardised  region  which  is,   for  any  given   ship,  merely  a   good
approximation of the fins) is also fatal unless you are playing with partial
damage (see below) and have not been  hit on that fin yet.  The debris  from
an explosion is not lethal.  (This may change some day!)

PARTIAL DAMAGE

If you are playing with partial damage, then a torpedo or mine which strikes
the fin of a ship  merely inflicts partial damage.   The effect is that  the
ship is no longer able  to turn using that fin.   (E.g., a damaged left  fin
prevents you from rotating clockwise.)  If you are playing with  hyperspace,
the ship is no longer able to enter hyperspace, either.  A second hit on the
same fin will destroy the ship.  Whenever you are not maneuvering (that  is,
neither thrusting nor turning, although  you may be firing torpedoes),  your
crew is busy repairing any damage you have sustained.  After a fixed  period
of non-maneuvering (which need not be continuous), a damaged fin will  again
be operational.  No indication is given when this happens, but you can  wait
for it by holding down the "damaged" button and no others (except maybe  the
fire button), and your ship will eventually (if it lives long enough)  begin
to rotate.  Partial damage is also repaired when the ship has been destroyed
and recreated, either in the next game or by reincarnation (see below).

REINCARNATION

If at any time there is at most one ship surviving (ships in hyperspace  are
considered to be alive), then there is a slight delay (during which time the
surviving ship (if any) might get killed somehow), after which the  survivor
(if any) is considered to have won the round.  That ship gets one point (see
KILLER SCORE on previous page) and a new round is begun.  On the other hand,
as long as there are  two or more ships still  alive, ships which have  been
killed will be reincarnated.  (Exception: If all of the remaining ships have
run out of torpedoes, then dead ships are not reincarnated, points are given
to the survivors only if someone is dead, and a new round is begun.)

The reincarnation of a ship takes place a fixed length of time following its
destruction, and consists  of the  ship reappearing somewhere  at the  usual
starting distance from the sun.  The ship will have no initial velocity.  If
it had been partially damaged when destroyed it will now be repaired, and if
it had run out of torpedoes it will have a fresh supply.  Its probability of
exploding in hyperspace  will have been  set back to  the initial  (minimum)
value.  It may also find itself in the middle of a flurry of torpedoes  from
the other ships, but them's the breaks.  Note that, unlike with  hyperspace,
there is no advance warning when a ship is about to be reincarnated.

Partial damage, lack of torpedoes, and increased probability of exploding in
hyperspace are also done away  with for all ships at  the start of each  new
round.

If all space-mines have  been destroyed (one way  or another), then after  a
time all  the mines  (as many  as you  asked for)  will reappear  in  random
locations.  They may even reappear on top of your ship.  Too bad.

DRONES

Any ships whose buttons are not  being manned (possibly because the  buttons
aren't hooked up) are called "drones".   In the passive state, they tend  to
do very little except fall into the  sun and occasionally get shot.  If  you
ask for active drones (see previous page), however, then it is as though all
buttons were being held down.  (If you are playing with hyperspace, then  it
is as though only the fire and thrust buttons for each ship were held down.)
Thus all the ships will be blasting  merrily away, creating a fine state  of
confusion.  For good measure, if you are playing with partial damage and  no
hyperspace, then any  ship which  is shot  in the  fin will  begin to  turn,
usually toward its attacker.  

To assume manual control of a ship,  just press (or release) any button  for
that ship.  The  ship will immediately  be released to  manual control,  and
will remain  that way  until an  entire  round goes  by without  the  ship's
buttons being used, whereupon it will turn back into a drone.  (It will also
turn back into a drone if it gets killed and reincarnated in a single  round
without its buttons being used.   If your ship is  killed before you have  a
chance to do anything,  you can still  push any button  while waiting to  be
reincarnated, and it will keep you from becoming a drone.  Of course, if you
DO become a  drone, you'll regain  control as  soon as you  push a  button.)
Note that, due to the  way things are hooked up,  typing at the keyboard  is
indistinguishable from spacewar buttons being  pushed.  Hence any typing  at
the keyboard (once the game  has begun) will tend  to deactivate one or  two
drones for the remainder of the round.

As of this writing, one of the buttons  is a bit flakey, such that it  comes
on intermittently of its own accord.  This of course temporarily deactivates
that drone.  There are no plans to program around this.

HANDICAPS

If the  relative skills  of the  players are  too disparate  to make  for  a
challenging game, it  is possible to  give one or  more players a  handicap.
This is done by changing the HANDCP parameter (see next page for details  on
how to do this).  This  parameter is in octal,  and each digit controls  the
handicap for a different ship.  In order from right (octal 7) to left (octal
70000), the ships are: pointy fins (fins point back), round back (bottom  of
ship is rounded), concave fins (fins point forward), triangle fins (fins are
triangular), and funny fins (fins curve out and back).  Hence setting HANDCP
to, say, 307,  would give concave  fins a handicap  of 3 and  pointy fins  a
handicap of 7.

The effect of a handicap is to reduce the lifetime of (i.e. distance covered
by) the torpedoes of the handicapped  ship.  Each increment in the  handicap
from 0 to 7 decreases the life by 1/8 the normal life.  Thus, with a maximum
handicap (7), a ship can only shoot 1/8 as far as normal.  Needless to  say,
this is an extreme case,  but might be necessary  to even out the  disparity
between a veteran  player and a  beginner.  Even  with a handicap  of 7,  an
experienced player should be able to clean up against four drones.
			    RUN-TIME PARAMETERS

Certain parameters can be  changed while the game  is in progress.  For  the
most part these parameters  are "universal constants",  such as gravity  and
rotational velocity.  The  parameters, with  cryptic notes as  to what  they
are, are listed below.   To tweak a parameter  while running spacewar,  type
the name of the parameter followed by  a slash (/).  The current value  will
be typed, whereupon you may type the desired new value.  (To leave the value
unchanged, just type <cr>.)  Two special commands are also permitted:

	LIST/	lists all parameters and their current values
	CLEAR/	clears the screen of garbage

Ending a new value with alt-mode (instead of <cr>) also clears the screen.

If you exit by hitting <call> and then type START, the program will  restart
with the scores set  to zero, but without  affecting the current setting  of
the parameters  and without  going through  the initial  question-and-answer
sequence.

Since the  program  is  not doing  any  I/O  except when  you  are  tweaking
parameters, you will (if  you play long enough)  get an autologout  warning.
Typing CLEAR/ is sufficient input to both clear the screen and stave off the
autologout.

In the following table, "Name" is the  name used to  refer to the  parameter
when changing it, "Initial" is its initial value, and "Mode" is the mode  in
which the parameter is displayed  and in which the  new value must be  typed
(floating point  decimal, fixed  decimal, fixed  octal, and  halfword  octal
(#,,#)).

Name	Parameter affected			Initial/mode	Limits

BTX	Thrust					1.6/float	None
BRX	Rotational speed			2.0/float	None
GG	Gravitional constant			32.0/float	None
GDT	Time delta for integration		6.0/float	None
MTCOLR	Mine-torpedo collision radius		100.0/float	None
TR2	Torp-torp collision radius (squared)	36.0/float	None
SCR	Sun collision radius			10.0/float	None
NTORPS	# torps per player			40/octal	≤40
TTBMAX	Maximum number of active torpedoes	132/octal	≤132
TRELOD	Torpedo reload delay			60/octal	≥20
LATNCY	Time between tubes			10/octal	None
TLIFE	Torpedo life before fading out		200/octal	≤200
ITV	Initial torpedo velocity		3400000/hf-wds	None
HANDCP	Handicaps (see previous page)		0/octal		None
SURBEN	Survival benefit (points for winning)	1/dec		None
KILLBN	Wages of sin (points for killing)	0 or 1/dec	None
DIEPEN	Death penalty (points lost if killed)	0 or 1/dec	None
DOTEAM	Team scoring if non-zero		0 or 1/octal	None
GSCORE	Show galaxy score (sun & mines) if ≠0	0/dec		None
RSTARD	Time between death and reincarnation	400/octal	None
FIXTIM	Time taken to fix partial damage	400/octal	None
DRONES	Drones active if ≠0			0 or 1/octal	None


Some notes on interesting things to tweak:

Setting BTX negative  leads to a  strange game.  Essentially  you then  have
funny-looking ships with torpedo tubes facing backwards.

If RSTARD is ≤20,  the game almost  never ends.  (That  is, there is  almost
never a single survivor due to everybody else coming back so quickly.)

If FIXTIM is made ≤0, partial damage is never repaired.

TLIFE should be made small if ITV is made large.

The galaxy score (number of  ships killed by the  sun and mines), if  turned
on, is displayed next to the sun.

If ITV  is particularly  large, the  discrete time  simulation  occasionally
fails to detect a torpedo  going through a ship (because  it is on one  side
and then the other without having been inbetween).  This situation, known as
"delta-t winning again", happens sometimes  even with the default  settings,
but becomes more noticeable as things speed up.  Making GDT smaller does not
seem to affect this.

Make TRELOD =20 for a steady spray.

A fairly standard set of tweaks to speed the game slightly is to set BTX  to
2, BRX to 2.5,  GG to 40, RSTARD  to 200, TLIFE to  140 (to account for  the
fact that the torpedoes will be going faster), and TRELOD to 50.