MirOS Manual: atc(6)

ATC(6)                       BSD Reference Manual                       ATC(6)


     atc - air traffic controller game


     atc [-lpqstu?] [-fg game name] [-r random seed]


     atc lets you try your hand at the nerve-wracking duties of an 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.

     -f game   Play the named game. If the game listed is not one of the ones
               printed by the -l option, the default game is played.

     -g game   Same as -f.

     -l        Print a list of available games and exit. The first game name
               printed is the default game.

     -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.

     -q        Play quietly (no bells).

     -s        Print the score list (formerly the Top Ten list). The scoring
               information is the game time in "radar updates", the wall-clock
               game time, and the number of planes that were successfully
               dealt with.

     -t        Same as -s.

     -r seed   Set the random seed. This option can be used to replay a
               specific game.

     -u        Print the usage line and exit.

     -?        Same as -u.


     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 air-
     port); and maneuver planes out of exit points.

     Several things will cause the end of the game. Each plane has a destina-
     tion (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 de-
     fined as adjacency, horizontal or vertical. A plane leaving the arena in
     any other way than through its correct destination exit is an error as

     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


     Depending on the terminal used, the atc 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 depend-
     ing 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


     The first screen area is the radar display, showing the relative loca-
     tions 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 termi-
     nals, prop planes are represented by an 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 '^', '>', '<', or '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 pur-
     pose is to offer a place of easy reference to the plane pilots. See The
     Delay Command under the input section of this manual.

     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 al-
     ways enter the arena from this direction. On the ASCII version of atc,
     this direction is not displayed. It will become apparent what this direc-
     tion is as the game progresses.

     Incoming planes will always enter at the same altitude: 7000 feet. For a
     plane to depart successfully through an entry/exit point, it must be fly-
     ing at 9000 feet. It is not necessary for the planes to be flying in any
     particular direction when they leave the arena (yet).


     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 current-
     ly 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 al-
     titude, an optional asterisk indicating low fuel, the plane's destina-
     tion, and the plane's current command. Changing altitude is not con-
     sidered 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 (Southwest).


     The third area of the display is the input area. It is here that your in-
     put is reflected. See the INPUT heading of this manual for more details.


     This area is used simply to give credit where credit is due. :-)


     A command completion interface is built into the game. At any time, typ-
     ing '?' 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 of-
     fending statement will be underscored and a (somewhat) descriptive mes-
     sage 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 the keys around the 's' key, namely "wedcxzaq". In abso-
     lute references, 'q' refers to Northwest 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 direc-

     All commands start with a plane letter. This indicates the recipient of
     the command. Case is ignored.


     a [ cd+- ] number
           Altitude: Affect a plane's altitude, possibly requesting takeoff.
           '+' and '-' are the same as 'c' and 'd'.
           a [0-9]     Go to the given altitude (thousands of feet).
           c [0-9]     Climb: Relative altitude change (thousands of feet).
           d [0-9]     Descend: Relative altitude change (thousands of feet).

     m     Mark: Display in highlighted mode. Plane and command information is
           displayed normally.

     i     Ignore: Do not display highlighted. Command information 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.


     c     Circle: Have the plane circle.

     t [ l-r+LR ] [ dir ] or tt [ abe* ] number
           Turn: Change direction.
           t<dir>      Turn to the absolute compass heading given. The shor-
                       test turn will be taken.
           tl          Left: Turn counterclockwise (45 degrees by default).
                       tl <dir>  Turn ccw the given number of degrees. Zero
                                 degrees ('w') is no turn; 45 degrees ccw is
                                 'e'. The shortest turn will be taken; for in-
                                 stance, if you specify a ccw turn of 315 de-
                                 grees ('q'), which should take several turns,
                                 the plane will really turn 45 cw, which takes
                                 only one turn.
           tr          Right: Turn clockwise (45 degrees by default).
                       tr <dir>  Analogous to turn left <dir>.
           tL          Turn counterclockwise 90 degrees.
           tR          Turn clockwise 90 degrees.
           tt [abe*]   Towards: Turn towards a beacon, airport or exit. The
                       turn is just an estimate.
                       ttb number  Turn towards the specified beacon.
                       tt* number  Equivalent to ttb.
                       tte number  Turn towards the specified exit.
                       tta number  Turn towards the specified airport.


     The Delay (a/@) command may be appended to any Delayable command. It al-
     lows the controller to instruct a plane to do an action when the plane
     reaches a particular beacon (or other objects in future versions).

           a/@     At: Do the given delayable command when the plane reaches
                   the given beacon.
                   ab number   The letter is redundant to allow for expansion.
                               '@' can be used instead of 'a'.


     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 unmarked plane is drawn in unhighlight-
     ed 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 ignored plane is treated the same as an unmarked 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.


           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


     •   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 air-

     •   Planes waiting at airports can only be told to take off (climb in

     •   Pressing return (that is, entering an empty command) will perform the
         next update immediately. This allows the player to "fast forward" the
         game clock if nothing interesting is happening.


     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 fol-

           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
     parentheses). Airports and exits require a third value, a direction,
     which is one of "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 in-
     clusive. 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.


           # 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 are kept in a special directory, which can be shown by using the -p

     /var/games/atc_score            Score file.
     /usr/share/games/atc/Game_List  The list of playable games.


     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.


     The screen sometimes refreshes after you have quit.

MirOS BSD #10-current            May 31, 1993                                5

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