term% cat index.txt ATC(6) Games Manual ATC(6)
NAME
atc - air traffic controller
SYNOPSIS
/usr/games/atc
DESCRIPTION
Atc presents air traffic on a cursor-controlled screen. As the con‐
troller, you must shepherd it safely through the air space. At the be‐
ginning of the game atc displays the takeoff/landing direction for each
airport and prompts for the game duration with:
< > enter a number from 16 simulated minutes (hard) to 99 (easier)
Options are
-u=file take airspace description from file
-a=name use the named airspace; default is `Apple1'
-s=seed a number for seeding a 32-bit random number generator
-t=time preset the game duration
-p=file save the play of the game in the named file
-m=file play a `movie' of the saved game
The initial display of a typical airspace looks like this:
. 0 . . . . . . 1 . . . . . . . . . . . . . .
. . , . . . . . , . . . . . . . . . . . . . .
. . . , . . . . , . . . . . . . . . . . . . 2
. . . . , . . . , . . . . . . . . . . . . , .
. . . . . , . . , . . . . . . . . . . . , . .
. . . . . . , . , . . . . . . . . . . , . . .
. . . . . . . , , . . . . . . . . . , . . . .
6 , , , , , , , * , , , , , , , , , , , , , 3
. . . . . . . . , , . . . . . . , . . . . . .
. . . . . . . . , . , . . . . , . . . . . . .
. . . . . . . . , . . , . . % . . . . . . . .
. . . . . . . . , . . . , , . . . . . . . . .
. . . . . . . . , . . . , , . . . . . . . . .
. . . . . . . . , . . , . . , . . . . . . . .
. . . . . . . . , . , . . . . , . . . . . . .
. . . . . . . . , , . . . . . . , . . . . . .
4 , , , , , , , * , , , , , # , , , , , , , 5
. . . . . . . , , . . . . . . . . . , . . . .
. . . . . . , . , . . . . . . . . . . , . . .
. . . . . , . . , . . . . . . . . . . . , . .
. . . . , . . . , . . . . . . . . . . . . , .
. . . , . . . . , . . . . . . . . . . . . . 9
. . 7 . . . . . 8 . . . . . . . . . . . . . .
% and # denote airports, * and ! denote navigational aids (navaids),
and commas denote airways that link entry/exit `fixes', airports, and
navaids. Dots are separated by one mile, horizontally, vertically, and
diagonally. An airplane appears as a letter followed by its height in
thousands of feet.
There are two kinds of planes: jets flying 1 mile per tick (15 seconds)
and props flying 1/2 mile per tick.
You must prevent various misfortunes. Running out of fuel is serious.
So is a close encounter - less than 3 miles horizontal separation at a
given altitude. A plane changing altitude is considered to be at both
its old and new altitudes. A `boundary error', leaving the airspace at
the wrong place, not on an airway, or at the wrong height, is also se‐
rious, but not as likely to be fatal.
The right side of the screen shows flight plans. A typical flight
strip looks like:
Fj 7->3 4 NE +
The first letter is the aircraft ID, the next letter is `j' for jet or
`p' for prop. The next field gives the plane's intentions: this one is
entering at (or is now at) fix 7 and leaving at fix 3. The origin
character tells where the plane is (or will be when it enters), the
destination is a fix it wishes to go to. (It will, however, continue
on a straight path unless instructed otherwise.) Next is the altitude,
in this case 4000 feet. The bearing is a compass direction: N, NE, E,
etc. The final character is the amount of fuel left, `+' for more than
10 minutes, otherwise the number of minutes of fuel remaining. Jets
begin with 15 minutes of fuel, props 21.
At the top of the flight plans are listed planes that will appear in
the next minute, preceded by how many ticks (0-4) they are away.
Planes may be cleared for takeoff as soon as they are listed.
Commands are terminated by <RETURN>. <BACK SPACE> may be used to cor‐
rect errors. The following kinds of commands can be issued.
$
End the game (game normally ends after 26 planes)
W Print flight plan for airplane W
XA3 X will change altitude to 3000 feet
QA0 Q will land (go to 0 feet altitude)
HRE H will turn right until it is heading east
ALNW A will turn left until it is heading northwest
CTS C will turn south through the smallest angle
T*7 T will take exit bearing for fix 7 at next navaid
P*% P will take landing bearing for % at next navaid
DH D will circle (hold) at next navaid
MR0 Abort pending hold, clearance, or turn for plane M
J? Cancel delayed commands for J
<SPACE>
Speed up the game by advancing 15 seconds
Climbing/descending. Planes climb or descend 1000 feet per mile.
Climbing from 0 is a takeoff; descending to 0 is a landing. The take‐
off/landing direction for each airport is given. A landing airplane
must reach altitude 0 headed in the right direction 1 mile before the
runway. No further commands may be given after a descent to 0, as con‐
trol then rests with the tower. If a plane lands from the wrong direc‐
tion, it will climb to 1000 feet and issue a `go around' error. While
changing altitude, a flight strip reads like
Dp :->2 7v3 S 9
which means at 7000 feet descending to 3000.
Turning. Planes turn 45 degrees per mile. Turns may be left (L) right
(R) or to a specified direction (T). Thus `ULNE' tells the pilot of
plane U to turn to his left until he is heading northeast. Changes of
direction are indicated in the flight strip:
Nj :->5 5 S r W +
indicates that jet N is heading south, and will turn 90 degrees to the
right. To cancel the remaining part of a turn, give the command (for
plane N) `NR0'.
Navaids. A plane may be directed to turn at a navaid or hold (circle)
there, Thus command `AH' holds plane A at the next navaid. The flight
strip for a plane that is to hold looks like
Ap :->2 5 S * 7
During the hold, the `*' will become `h'. Every incoming plane that
will be landing holds at a navaid unless the controller gives it other
instructions.
The command `*' clears a plane to turn sharply to any known fix at the
next navaid. The flight strip for a plane cleared through a navaid (to
fix 5, for example) looks like:
Hj .->2 5 S *5 +
A holding aircraft given a clearance will continue around to the
navaid, then immediately assume the specified bearing. Turns cancel
clearances.
Delayed commands. Commands of the form
@<location>,<command>[,<command> ...]
stack up activities. A location may be any fix or a point offset from
a fix, e.g.
@#sw3s2,ARE
which means at the point which can be reached by going three miles SW
from airport #, then two miles S, plane A should begin a right turn un‐
til heading E. The information command shows all delayed commands
pending for that plane. Note that delayed commands allow one to spec‐
ify actions more than one navaid ahead.
ATC(6)