Lunar Lander

Lunar Lander is the name of several video games. In all variations of the game, the player must portion a limited amount of fuel to land on the moon without crashing. Computer Gaming World described it as one of the first fun programs neophyte programmers start with and continually improve upon as they improve their skills.

Lunar Lander (1969)
Lunar Lander started as a text-based computer game and went by the names Rocket, Lunar, LEM, and Apollo. Lunar was originally written in FOCAL (a DEC language for the PDP-8) by Jim Storer while a student at Lexington (MA) High School in the fall of 1969. A somewhat different version called Rocket was written in BASIC by Eric Peters at DEC, and a third version, LEM, also in BASIC was written by William Labaree II of Alexandria, VA. David Ahl converted Jim Storer's FOCAL version to BASIC, changed some of the dialog, published it in the EDU newsletter and distributed it through DEC's Education Product Group, which he headed at the time. A year or so later, all three BASIC versions first appeared under the names ROCKET (Storer version), ROCKT1 (Peters version), and ROCKT2 (Labaree version) in David Ahl's book, 101 Basic Computer Games published by DEC in 1973. David Ahl and Steve North converted all three versions to Microsoft BASIC, changed the name to Lunar Lander, and published them in Creative Computing magazine in 1976. They also appeared in an updated version of Ahl's games book simply called BASIC Computer Games published in 1978.

Lunar Lander (1973)
Lunar Lander (also known as Moonlander) is an early computer game that runs on the DEC GT40 graphics terminal (typically downloaded from a PDP-10 mainframe computer). DEC commissioned the game to be written in 1973 as a demonstration of the capabilities of the GT40; it was seen at many trade shows.

The goal was to correctly land a lunar module on the surface of the moon using the game's telemetry data. If the player miscalculates the module's landing, the module will either fly off into space or crash hard against the moon's surface or the mountain over which the lander first passed. The interface was through a light pen and the output display was a vector graphics system; the light pen allowed adjusting the throttle value and the angle of the lunar lander. Sophisticated players could achieve a landing on the mountain while cheaters learned the address of the word of magnetic core memory in which the fuel value was stored.

Later versions offered the ability to run the game on a free-standing RT-11 system as well as an Easter egg: a specific landing site offered a McDonald's restaurant. Upon landing successfully near the restaurant, an astronaut would walk over to get lunch. Crashing into the restaurant destroyed it permanently (until the program was reloaded) and displayed an amusingly sarcastic message berating the player.

Lunar Lander by Atari (1979)
Lunar Lander is an arcade game released by Atari in 1979, that uses a vector monitor to display vector graphics. Lunar Lander featured two concepts previously unseen in arcade video games:
 * 1) A proportional throttle control that allowed perfect timing of fuel expenditure
 * 2) A 'fuel for money' system which allowed the player to spend money to continue their play and purchase more fuel in-game

Text version
A text-only version of Lunar Lander, written in BASIC, was included with the eight-inch floppy operating system diskettes for the Datapoint 2200 series in the early 1980s. Playing it required three separate loadings: first the operating system, then BASIC, and only then the program itself.

Calculator versions
A moon landing game was also popular on programmable calculators such as the Hewlett Packard models 65 and 67, and the Texas Instruments SR 52, using the calculator's single-line numeric display to show altitude and function keys to increase or decrease fuel flow. Later calculators had improved graphics with LCD screens.

Memorable words and phrases
Boy, are you inept! was the error message that appeared if the lunar lander went off either end of the map of the lunar surface. It became a cult phrase, for use as an error message for many in-house computer programs.