Name: Retrofire!
Platform: Atari 800
Region: USA
Media: Executable
Controller: Joystick
Genre: Simulation
Gametype: Magazine
Release Year: 1983
Developer: ANALOG Computing
Publisher: ANALOG Computing
Players: 1
Programmer: Tom Hudson
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ANALOG Computing Issue 14, 1983.

Your spacecraft was orbiting Jupiter when suddenly the radiation shielding failed.  Forced to eject in an escape capsure, you must now land on IO, the only moon with a safe landing area.  Your computers are able to take you to  within 20,000 feet of the surface, where you must take controls for the final approach and landing.  Along with the obvious danger of crashing into the surface, you must avoid intense radiation from Jupiter and erupting volcanoes on Io's surface!

Retrofire requires one joystick in port 1.

When the game begins you will be shown a display of your escape pod's console, with the game credits.  You have two factors that influence game difficulty, GRAVITY and FUEL.

The gravity level can be set to L (low), M (medium), or H (high).  Low gravity is recommended for beginners.  Select the desired gravity level by pressing the OPTION key.

The fuel level can range from 5,000 to 14,000 units.  Select the desired fuel amount by pressing the SELECT key.  Normal gravity/fuel amoutns are Low gravity, 7,000 units; Medium gravity, 10,000 units; and High gravity, 14,000 units.

There is one other option before beginning the game.  The "C" key on the keyboard will toggle the playfield colors, enabling you to select the color combination you prefer.

Once you have selected the game difficulty, press START to begin the game.

The Retrofire display.

Figure 1 shows the retrofire game display.  This screen shows you all the information necessary to safely land your escape pod.

Starting at the upper right side of the display, you will see the box with the word "RADIATION."  This is a vertical bar graphi indicating the amount of radiation you have accumulated on your descent.  The higher your ship is in IO's thin atmosphere, the faster you accumulate radiation from Jupiter's radiation belt, so it's a good idea to get to a lower altitude as fast as possible.

Radiation can also be accumulated from Io's many volcanoes, described below.  If the radiation level ever gets too high, your ship's vital electronics will overload, and the craft will explode.

To the left of the radiation display is the navigational position readout.  This display shows our ship's coordinates as well as the coordinates of the landing pad.

While the base's position is alway sknow, at above 1,000 fett the navigational computer can only provide an approximation of your ship's position.  Once you pass below 1,000 feet, the computer must use landmarks to show your exact position.  When you match your coordinates to the base's coordinates, you are directly over the base and can land safely.

Below the navigational position displays are your five most important readouts.

The ALT reading shows your ship's altitude (in feet) in relation to the landing pad.  Beware:  Mountain heights are not taken into account here!

The next three readouts are what make Retrofire different from other "Lunar Lander" type programs: three dimensions!

These three readings are the X, Y and Z velocities of your ship in feet per second.  To the left of each velocity reading is an arrow indication the direction of movement.  The axis labeling is non-standard, so read carefully.

The X velocity (XV) tells how fast your ship is going up or down.  If the arrow is pointing up, you are ascending.  If it is pointing down, you are descending.  Pushing your joystick up will fire the main retrorockets, slowing your descent.  Pushing the stick down will force you down toward Io's surface.  The X velocity MUST be lower than 11 feet per second for a safe landing.

The Y velocity (YV) tells how fast your ship is going to the right or left over the terrain grid (described below).  Once again, the arrow to the left of the velocity value indicates the direction of movement.  Push your stick to the left to decrease the Y velocity and to the right to increase it.  Your Y velocity MUST be lower than 6 feet per second for a safe landing.

The Z velocity (ZV) tells how fast your ship is going diagonally over the terrain grid, the third dimension in this game.  You can think of this dimention as depth into your TV screen.  Push you stick to the lower left to decrease this value and to the upper right to increase it.  Your Z velocity MUST be lower than 6 feet per second for a safe landing.

Your ship has a "terminal velocity" of 500 feet per second.  That is, your ship cannot go faster than 500 feet per second in any direction, no matter how much you try.

To the right of each velocity indicator is a color-coded engine temperature light.  When green, the engine temperature is OK, and the engine is working normally.  As you fire each engine, it heats up.  When the engine is not being fired, it will cool down.  Wise use of the engines will keep the engines cool and safe.

If, however, you fire an engine for too long, it will begin to overheat.  As the engine heats up, the temperature light will go from green to yellow to red.  As the engine heats up to the yellow and red zones, it will bein to fail, losing efficiency.  If the engine is forced to operate in the red zone too long, the indicator will turn dark gray, indicating engine burnout.  If this happens, the engine is dead and you will probably crash.  Whenever the temperature status of an engine changes, you will be alerted with a short tone.

Below the velocity indicators is the ship's fuel level.  As you fire the engines, fuel is subtracted from your initial supply.  When your fuel supply drops below 1000 units you will receive a warning message and a tone.  If the fuel level reaches zero, an "OUT OF FUEL" message is displayed with a lower pitch tone.

Directly below the fuel indicator is a display showing the number of ships you have left.

The game score is shown below the number of ships left.  Each time you land safely, you are awarded ten points for each unit of fuel remaining.  This feature is primarily for compeition between two players.

The largest area of the display is the graphic terrain display on the left side of the screen.  This display shows the terrain directly below the ship.  Your ship is displayed as a white square over the terrain grid, with a gray "shadow" on the grid to indicate your exact position and the terrain height below your ship.

Your objective is to land in the grid square which contains your landing pad, indicated by a flashing red "+."

As your ship begins its descent, the terrain will appear very flat.  This is because surface details cannot be seen at this altitude.  As your ship descends below 800 feet, the computer will "zoom in" on the square your ship is over, enlarging it to a new 7x7 grid.  At this point, terrain detail will begin to show up.  You will notice that your spacecraft appears to move faster at this magnification, due to the "zoom" effect.

As your ship descends below 1000 feet, once again the computer will "zoom in" on the square below your ship, enlarging it to a new 7x7 grid.  This is the final stage of your approach toward the surface.  At this magnification level you must pay close attention to the terrain and your shadow.  Your shadow indicates how close to the ground, and if you ship hits any peaks, you will be destroyed.  A good rule of thumb is to cruise over the surface at an altitude of around 500 feet.

While yo u are below 1000 feet, you must watch out for volcanoes.  These erupting mountains constantly spew radioactive debris.  If your ship passes directly over a volcano at an altitude of less than 500 feet, you will be exposed to a potentially lethal dose of radiation.  It's a good idea to keep an eye on your radiation indicator at this point.  This number of volcanoes increases each time you land successfully.

At the top of the graphic display window is a warning message area.  This areaa will display fuel warning and other messages as necessary.

If you need to pause the game during descent, simply press the space bar.  The game can be resumed by pressing the space bar a second time.

Some notes on playing Retrofire.

Those who are expecting Retrofire to be a fast-action shoot-em-up are in for a surprise.  This is a fairly realistic simulation program with game elements, not something you'd expect to find in an arcade.

Retrofire can be quite difficult on the higher gravity settings but with practice it can be mastered.

Probably the toughest thing about Retrofire is getting accustomed to the X-Y-Z axis system and the joystick control.

Figure 2 shows the relationship of the joystick to the movement on the screen.  It's actually very simple, but it takes some practice to activate the Z-axis engines, which are diagonals on the joystick.

The other conecpt which can be confusing to beginning players is the "zoom" function.  This occurs at altitudes of 8000 and 1000 feet

Figure 3 shows how this magnification works.  Although the highest grid (altitude 8000 feet) is made up of 49 squares (7x7 squares), each of these squares, when enlarged at altitudes less than 8000 feet, can be shown to contain another 49 smaller squares.  When the altitude drops to less than 1000 feet, the swuare the ship is over enlarges further still, showing that each of these squares also contains 49 smaller squares.

By doing some quick math, you can see that the highest 7x7 grid actually represents 343x343 squares, or a total surface of 117,649 squares!

With over 117,000 possible places to land, it's obvious that the best strategy is to always keep yourself positioned over the grid square with the base symbol, you can always fly across to the base by using the navigational coordinates at the top of the screen.  This requires more concentration than using the drid, so be forewarned!

Once again, this game is somewhat tricky, so just stick with it, and soon you'll be qualified to land almost any spacecraft.
