man acm4 (Jeux) - an aerial combat simulator for X (version 4.X)


acm - an aerial combat simulator for X (version 4.X)


acm4 [ server ] [ options ]


acm is an air combat simulator that runs under the X window system. Up to eight players can engage in simultaneous air combat. Players fly jet aircraft equipped with radar, heat seeking missiles and cannon.

The program, "acm4", calls a daemon already running on the specified server_hostname and requests that your enter the game. The shell variable "ACMSERVER" optionally specifies the name of the server host.

Each player flies something close to either an F-16C Falcon or MIG-23.


To begin play, the flight simulator server must be started manually on a system that is accessible to all players.

The following command line will do that:

% acms

The kill-acms program may be called to kill the acms server.

The following command line options are recognized by acm:

-geometry geometry_spec
An X compatible window geometry specification
-team <1 or 2>
Specifies the starting airfield. Airfields are about 50 nm apart. Team 1 flies F-16's, team 2 flies MIG-23's.
Use the X server's default visual for your screen. Normally, acm will hunt for a Visual that has a depth of eight planes. It will also create a private colormap for acm's use. If your screen's default Visual is an 8-plane PseudoColor Visual, using this switch will allow acm to use the "public" Colormap so that other windows won't change color when acm is in use.


Your mouse is the control stick. The neutral position is the center of your view display -- denoted by the dot in the center of your heads-up-display (HUD). Moving the mouse away from you pitches the plane down, moving it back pitches the plane up. Left and right inputs roll the aircraft in the corresponding direction. On the ground at speeds up to 100 kts, nose wheel steering guides the aircraft.

To take off for the first time, select 20 degrees of flaps (press H twice), then press the full throttle key (the 4 key on the main keyboard). Keep the mouse in the neutral position until you are moving at about 140 kts, then pull the mouse about two-thirds of the way down the view window. You should pitch up and lift off the ground fairly easily. Gradually move the stick closer to the neutral position and let your airspeed build -- don't move it back to neutral too quickly or you will end up back on the ground again! As your airspeed passes about 250 kts, raise the flaps (press Y twice) and landing gear (press G). Congratulations, you're flying a multi-million dollar jet.


The following keys control your engine thrust:

4 Full Power

3 Increase Power (about 2 percent)

2 Decrease Power (about the same amount)

1 Idle Power

A Toggle Afterburner

Your engine gauge displays the power that you are generating. Below that, you have displays showing your total fuel remaining as well as your current fuel consumption rate. The afterburner uses fuel at an amazing rate; use it wisely.


The keys of the numeric keypad control which direction you're looking outside of the cockpit:

8 Forward 4 Left 5 Up 6 Right

2 Aft

It pays to look around when you're in a combat environment. Your chances of staying alive increase remarkably.


On the left side of the HUD is a ladder showing your current airspeed in nautical miles per hour (it displays true airspeed). Above that, in the upper left corner, is a G-meter.

The right ladder shows altitude; above that is a readout of your current angle-of-attack in degrees ("a=X.X"). Your jet will stall at a 30 degrees positive angle of attack and negative 16 degrees.

The airplane symbol (something like "-O-") shows the direction that the relative wind is coming from. The relative wind combines your current angles of attack and sideslip. A ladder in the center of the HUD show your aircraft's current attitude.

The lower, horizontal ladder shows your current heading. Discretes in the lower left-hand corner show the state of your weapons systems. Slightly above them is a readout of your current thrust percentage as well as the state of your engine's afterburner -- the "AB" symbol means the afterburner is on.


The radar system has a field of view of 130 degrees vertically and side-to-side. Radar automatically locks onto the closest threat in its field of view. A locked target is displayed as a solid block. Other hostile targets are displayed as hollow squares.

Targetting information is displayed in the lower right corner of the display. The top number is the heading of the locked target, the next number is the relative heading you should steer to intercept the target (displayed as "ddd R", and the third number is the rate that you are closing with this target, expressed in knots.

You can lock onto other targets by pressing the target designator key (Q).


Radar sets that are tracking your aircraft can be detected. Your Threat Early Warning System (TEWS) display warns you of potential threats. This circular display shows the relative direction of radars (other aircraft) that are looking at you.


Your aircraft is equipped with heat-seeking missiles and a 20 millimeter cannon. Weapon information is displayed in the lower left-hand corner of your HUD. Different weapons may be selected by pressing mouse button 3.

The missiles are patterned after U.S. AIM-9M Sidewinders. They can detect infared (IR) targets at any aspect (not just from the rear). Their range varies dramatically with the altitude and closure rate. The missile subsystem couples with your radar set to provide time-to-impact information when AIM-9's are selected.


acm bismarck

acm bismarck -geometry 1000x500


Stick and Rudder Controls

The Mouse if your stick. It controls pitch and roll.

Z -- Rudder Left

C -- Rudder Right

X -- Center the Rudder

Engine Controls

4 -- Full Power

3 -- Increase Power

2 -- Decrease Power

1 -- Idle

A -- Toggle Afterburner State

Radar Controls

R -- Toggle Radar State (On/Standby)

Q -- Target Designator


H -- Extend 10 degrees

Y -- Retract 10 degrees

Speed Brakes

S -- Extend

W -- Retract

Weapon Controls

Mouse Button 2 -- Fire the selected weapon

Mouse Button 3 -- Select another weapon

Pitch Trim Controls

U -- Set Take-off pitch trim

J -- Set pitch trim to the control stick's current pitch setting

Other Controls

G -- Retract/Extend landing gear

P -- Self-Destruct (Quit the game)

L -- Launch a target drone

View Controls (Numeric Keypad)

8 -- Forward

2 -- Aft

4 -- Left

6 -- Right

5 -- Up


Riley Rainey,