Provided by: bsdgames_2.17-33_amd64 
NAME
atc — air traffic controller game
SYNOPSIS
atc [-u?lstp] [-gf game name] [-r random seed]
DESCRIPTION
atc lets you try your hand at the nerve wracking duties of the air traffic controller without endangering
the lives of millions of travelers each year. Your responsibilities require you to direct the flight of
jets and prop planes into and out of the flight arena and airports. The speed (update time) and
frequency of the planes depend on the difficulty of the chosen arena.
OPTIONS
-u Print the usage line and exit.
-? Same as -u.
-l Print a list of available games and exit. The first game name printed is the default game.
-s Print the score list (formerly the Top Ten list).
-t Same as -s.
-p Print the path to the special directory where atc expects to find its private files. This is used
during the installation of the program.
-g game
Play the named game. If the game listed is not one of the ones printed from the -l option, the
default game is played.
-f game
Same as -g.
-r seed
Set the random seed. The purpose of this flag is questionable.
GOALS
Your goal in atc is to keep the game going as long as possible. There is no winning state, except to
beat the times of other players. You will need to: launch planes at airports (by instructing them to
increase their altitude); land planes at airports (by instructing them to go to altitude zero when
exactly over the airport); and maneuver planes out of exit points.
Several things will cause the end of the game. Each plane has a destination (see information area), and
sending a plane to the wrong destination is an error. Planes can run out of fuel, or can collide.
Collision is defined as adjacency in all three dimensions. A plane leaving the arena in any other way
than through its destination exit is an error as well.
Scores are sorted in order of the number of planes safe. The other statistics are provided merely for
fun. There is no penalty for taking longer than another player (except in the case of ties).
Suspending a game is not permitted. If you get a talk message, tough. When was the last time an Air
Traffic Controller got called away to the phone?
THE DISPLAY
Depending on the terminal you run atc on, the screen will be divided into 4 areas. It should be stressed
that the terminal driver portion of the game was designed to be reconfigurable, so the display format can
vary depending on the version you are playing. The descriptions here are based on the ascii version of
the game. The game rules and input format, however, should remain consistent. Control-L redraws the
screen, should it become muddled.
RADAR
The first screen area is the radar display, showing the relative locations of the planes, airports,
standard entry/exit points, radar beacons, and ``lines'' which simply serve to aid you in guiding the
planes.
Planes are shown as a single letter with an altitude. If the numerical altitude is a single digit, then
it represents thousands of feet. Some distinction is made between the prop planes and the jets. On
ascii terminals, prop planes are represented by a upper case letter, jets by a lower case letter.
Airports are shown as a number and some indication of the direction planes must be going to land at the
airport. On ascii terminals, this is one of `^', `>', `<', and `v', to indicate north (0 degrees), east
(90), west (270) and south (180), respectively. The planes will also take off in this direction.
Beacons are represented as circles or asterisks and a number. Their purpose is to offer a place of easy
reference to the plane pilots. See “THE DELAY COMMAND” section below.
Entry/exit points are displayed as numbers along the border of the radar screen. Planes will enter the
arena from these points without warning. These points have a direction associated with them, and planes
will always enter the arena from this direction. On the ascii version of atc, this direction is not
displayed. It will become apparent what this direction is as the game progresses.
Incoming planes will always enter at the same altitude: 7000 feet. For a plane to successfully depart
through an entry/exit point, it must be flying at 9000 feet. It is not necessary for the planes to be
flying in any particular direction when they leave the arena (yet).
INFORMATION AREA
The second area of the display is the information area, which lists the time (number of updates since
start), and the number of planes you have directed safely out of the arena. Below this is a list of
planes currently in the air, followed by a blank line, and then a list of planes on the ground (at
airports). Each line lists the plane name and its current altitude, an optional asterisk indicating low
fuel, the plane's destination, and the plane's current command. Changing altitude is not considered to
be a command and is therefore not displayed. The following are some possible information lines:
B4*A0: Circle @ b1
g7 E4: 225
The first example shows a prop plane named `B' that is flying at 4000 feet. It is low on fuel (note the
`*'). Its destination is Airport #0. The next command it expects to do is circle when it reaches Beacon
#1. The second example shows a jet named `g' at 7000 feet, destined for Exit #4. It is just now
executing a turn to 225 degrees (South-West).
INPUT AREA
The third area of the display is the input area. It is here that your input is reflected. See the
“INPUT” heading of this manual for more details.
AUTHOR AREA
This area is used simply to give credit where credit is due. :-)
INPUT
A command completion interface is built into the game. At any time, typing `?' will list possible input
characters. Typing a backspace (your erase character) backs up, erasing the last part of the command.
When a command is complete, a return enters it, and any semantic checking is done at that time. If no
errors are detected, the command is sent to the appropriate plane. If an error is discovered during the
check, the offending statement will be underscored and a (hopefully) descriptive message will be printed
under it.
The command syntax is broken into two parts: Immediate Only and Delayable commands. Immediate Only
commands happen on the next update. Delayable commands also happen on the next update unless they are
followed by an optional predicate called the Delay command.
In the following tables, the syntax [0-9] means any single digit, and ⟨dir⟩ refers to a direction, given
by the keys around the `s' key: ``wedcxzaq''. In absolute references, `q' refers to North-West or 315
degrees, and `w' refers to North, or 0 degrees. In relative references, `q' refers to -45 degrees or 45
degrees left, and `w' refers to 0 degrees, or no change in direction.
All commands start with a plane letter. This indicates the recipient of the command. Case is ignored.
IMMEDIATE ONLY COMMANDS
a [ cd+- ] number
Altitude: Change a plane's altitude, possibly requesting takeoff. `+' and `-' are the same as `c'
and `d'.
a number Climb or descend to the given altitude (in thousands of feet).
ac number Climb: relative altitude change.
ad number Descend: relative altitude change.
m Mark: Display in highlighted mode. Plane and command information is displayed normally.
i Ignore: Do not display highlighted. Command is displayed as a line of dashes if there is no
command.
u Unmark: Same as ignore, but if a delayed command is processed, the plane will become marked. This
is useful if you want to forget about a plane during part, but not all, of its journey.
DELAYABLE COMMANDS
c [ lr ]
Circle: Have the plane circle.
cl Left: Circle counterclockwise.
cr Right: Circle clockwise (default).
t [ l-r+LR ] [ dir ] or tt [ abe* ] number
Turn: Change direction.
t<dir> Turn to direction: Turn to the absolute compass heading given. The shortest turn will
be taken.
tl [ dir ] Left: Turn counterclockwise: 45 degrees by default, or the amount specified in ⟨dir⟩
(not to ⟨dir⟩.) `w' (0 degrees) is no turn. `e' is 45 degrees; `q' gives -45 degrees
counterclockwise, that is, 45 degrees clockwise.
t- [ dir ] Same as left.
tr [ dir ] Right: Turn clockwise, 45 degrees by default, or the amount specified in ⟨dir⟩.
t+ [ dir ] Same as right.
tL Hard left: Turn counterclockwise 90 degrees.
tR Hard right: Turn clockwise 90 degrees.
tt [abe*] Towards: Turn towards a beacon, airport or exit. The turn is just an estimate.
tta number Turn towards the given airport.
ttb number Turn towards the specified beacon.
tte number Turn towards an exit.
tt* number Same as ttb.
THE DELAY COMMAND
The Delay (a/@) command may be appended to any Delayable command. It allows the controller to instruct a
plane to do an action when the plane reaches a particular beacon (or other objects in future versions).
ab number
Do the delayable command when the plane reaches the specified beacon. The `b' for ``beacon'' is
redundant to allow for expansion. `@' can be used instead of `a'.
MARKING, UNMARKING AND IGNORING
Planes are marked by default when they enter the arena. This means they are displayed in highlighted
mode on the radar display. A plane may also be either unmarked or ignored. An ignored plane is drawn in
unhighlighted mode, and a line of dashes is displayed in the command field of the information area. The
plane will remain this way until a mark command has been issued. Any other command will be issued, but
the command line will return to a line of dashes when the command is completed.
An unmarked plane is treated the same as an ignored plane, except that it will automatically switch to
marked status when a delayed command has been processed. This is useful if you want to forget about a
plane for a while, but its flight path has not yet been completely set.
As with all of the commands, marking, unmarking and ignoring will take effect at the beginning of the
next update. Do not be surprised if the plane does not immediately switch to unhighlighted mode.
EXAMPLES
atlab1 Plane A: turn left at beacon #1
cc Plane C: circle
gtte4ab2 Plane G: turn towards exit #4 at beacon #2
ma+2 Plane M: altitude: climb 2000 feet
stq Plane S: turn to 315
xi Plane X: ignore
OTHER INFORMATION
• Jets move every update; prop planes move every other update.
• All planes turn at most 90 degrees per movement.
• Planes enter at 7000 feet and leave at 9000 feet.
• Planes flying at an altitude of 0 crash if they are not over an airport.
• Planes waiting at airports can only be told to take off (climb in altitude).
• Pressing return (that is, entering an empty command) will perform the next update immediately. This
allows you to ``fast forward'' the game clock if nothing interesting is happening.
NEW GAMES
The Game_List file lists the currently available play fields. New field description file names must be
placed in this file to be playable. If a player specifies a game not in this file, his score will not be
logged.
The game field description files are broken into two parts. The first part is the definition section.
Here, the four tunable game parameters must be set. These variables are set with the syntax:
variable = number;
Variable may be one of: update, indicating the number of seconds between forced updates; newplane,
indicating (about) the number of updates between new plane entries; width, indicating the width of the
play field; or height, indicating the height of the play field.
The second part of the field description files describes the locations of the exits, the beacons, the
airports and the lines. The syntax is as follows:
beacon: (x y) ... ;
airport: (x y direction) ... ;
exit: (x y direction) ... ;
line: [ (x1 y1) (x2 y2) ] ... ;
For beacons, a simple x, y coordinate pair is used (enclosed in parenthesis). Airports and exits require
a third value, which is one of the directions wedcxzaq. For airports, this is the direction that planes
must be going to take off and land, and for exits, this is the direction that planes will be going when
they enter the arena. This may not seem intuitive, but as there is no restriction on direction of exit,
this is appropriate. Lines are slightly different, since they need two coordinate pairs to specify the
line endpoints. These endpoints must be enclosed in square brackets.
All statements are semi-colon (;) terminated. Multiple item statements accumulate. Each definition must
occur exactly once, before any item statements. Comments begin with a hash (#) symbol and terminate with
a newline. The coordinates are between zero and width-1 and height-1 inclusive. All of the exit
coordinates must lie on the borders, and all of the beacons and airports must lie inside of the borders.
Line endpoints may be anywhere within the field, so long as the lines are horizontal, vertical or exactly
diagonal.
FIELD FILE EXAMPLE
# This is the default game.
update = 5;
newplane = 5;
width = 30;
height = 21;
exit: ( 12 0 x ) ( 29 0 z ) ( 29 7 a ) ( 29 17 a )
( 9 20 e ) ( 0 13 d ) ( 0 7 d ) ( 0 0 c ) ;
beacon: ( 12 7 ) ( 12 17 ) ;
airport: ( 20 15 w ) ( 20 18 d ) ;
line: [ ( 1 1 ) ( 6 6 ) ]
[ ( 12 1 ) ( 12 6 ) ]
[ ( 13 7 ) ( 28 7 ) ]
[ ( 28 1 ) ( 13 16 ) ]
[ ( 1 13 ) ( 11 13 ) ]
[ ( 12 8 ) ( 12 16 ) ]
[ ( 11 18 ) ( 10 19 ) ]
[ ( 13 17 ) ( 28 17 ) ]
[ ( 1 7 ) ( 11 7 ) ] ;
FILES
Files are kept in a special directory. See the “OPTIONS” section for a way to print this path out. It
is normally /usr/share/games/bsdgames/atc.
This directory contains the file Game_List, which holds the list of playable games, as well as the games
themselves.
The scores are kept in /var/games/bsdgames/atc_score.
AUTHOR
Ed James, UC Berkeley: edjames@ucbvax.berkeley.edu, ucbvax!edjames
This game is based on someone's description of the overall flavor of a game written for some unknown PC
many years ago, maybe.
BUGS
The screen sometimes refreshes after you have quit.
Debian January 1, 2004 ATC(6)