 ANTIC VOL. 4, NO. 11 / MARCH 1986 / PAGE 73

game of the month

LUNAR LANDER CONSTRUCTION SET

Program by DANIEL DEIGHAN Article by GIGI BISSON

Lunar Laanders, games that simulate a space capsule landing on the moon, were among the first public domain programs. Now with Lunar Lander Construction Set you can easily create and save your own joystick-controlled space landing simulations. This BASIC program works on 8-bit Atari computers with 32K disk or 16K cassette.

Back in the old days, before Space Invaders, Player/Missiles, Asteroids and Moon Unit Zappa, there were Lunar Landers. Perhaps the oldest form of computer game, Lunar landers deserve a place on computer memory lane right next to Eliza, Life and Pong.
   These simulations of Apollo rocket ship landings, essentially working equations between velocity and gravity, were originally all-text programs on mainframes connected to teletypes. later, micro versions written in BASIC on the TRS-80, Apple II, Commodore VIC-20 and Atari 400 became some of the most common public domain programs. Those early Lunar landers tended to be boring, impossible to win, and generally unreliable. Sometimes the challenge was simply guessing which would crash first-your rocket or the program.
   The old text-based lunar landers were loaded with complicated mathematical equations, fuel units and thrust percentages, but the programmers' strange sense of humor helped keep them from lapsing into total tedium. When you crashed your rocket, a message would appear: "Sorry, there were no survivors. You blew it! In fact, you blasted a new lunar crater 347.12 feet deep!," or "Too bad, the space program hates to lose experienced astronauts! Appropriate condolences will be sent to your next of kin."
   Eventually lunar landers became one of the first games with graphics and sound (only one sound, but that was a mean feat in those days.) Whether these early programs were called Lunar, LEM (after the Apollo Lunar Excursion Module), Apollo, Rocket, orJupiter lander, the mission was always the same-land safely on the moon without crashing or running out of fuel. In some graphic versions, a successful landing was rewarded by the sight of a McDonald's nestled on the surface of the moon.

'86 LANDER
A few things set Daniel Deighan's Lunar lander apart. It's joystick controlled, so you won't have to deal with mathematical equations. He has updated it for the '80s-you'll land a space shuttle instead of a rocket. It's also a Lunar Lander Construction Set. You can choose varying levels of gravitational force and construct your own lunar landscapes, utilizing color, sound and a redefined character set.
To begin, type in Listing 1, LANDER.BAS, check it with Typo II and SAVE a copy before you RUN it. If you have problems with lines 1130-1140, don't bother to type them in. Listing 2 will create them for you. When you RUN Listing 2, it creates a file called LINES.LST which contains those special lines. Now, type NEW and then LOAD Listing 1, next ENTER "D:LINES.LST" and SAVE the completed program.

BLAST OFF
Sally Ride was busy making a cereal commercial, so among hundreds of qualified shuttle pilots, you've been chosen to deliver high explosives to ore miners on several planets. Your job is to guide your cargo shuttle from a stationary orbit to the landing pad-very softly, because the space program hates to lose astronauts.
   First, plug in one (or two) joysticks, then RUN the program. When the first lunar landscape screen appears, press [START]. The prompts will tell you to press [OPTION] to choose the number of players. Then press [SELECT] to choose your gravity level among nine different locations from Ganymede, the largest of Jupiter's moons, to Earth.
   To play, press [START] and hold the button down for a second or two. Use the joystick to guide your shuttle through the intimidating alien landscape onto the landing pad, which is designated with flashing lights. You can go left or right, push the stick up to fire your main thrusters, or down to fire your less powerful landing thrusters.
   If you land very softly (no easy feat) you will be given extra points. If you do a great job, you'll get bonus rocket fuel. If you blow it and crash, you'll get another chance, land successfully twice, without running out of fuel, and you can advance to the next mission.

BUILD A PLANET
Now that you know what a lunar lander looks like, you can design your own lunar landscapes, modify the screens already loaded into the game, or even load a whole new version of the game with your own landing sites. Enter the constructon set by pressng [OPTION] and [SELECT] simultaneously. At the first prompt, you can choose whether you want to alter an existing screen or start from scratch.
   If you choose to create a new screen, you will be asked if you want to load a previously saved screen. If so, first type in the device to load from (D: or C:). Otherwise the screen will revert to the figure selection menu.
   If you choose to alter an existing screen, you will be asked which screen you want to work on. The screen will be displayed and you'll be presented with the figure selection menu.
   Using your joystick, move the cursor (it's invisible, so this will be tricky) over the blue templates. Select little chunks of lunar turf, peaks and valleys by pressing the fire button. Then use the joystick to move the turf to the landscape screen, To put it in place, press the fire button as many times as you wish.
   To create solid fills, use the square piece of turf on the far left of the template. To erase, move the invisible cursor over the first space, fire, then move it over any part of the landscape you want to delete. To position a landing pad, select the third portion of the template with a small blue spot on top of it-this represents the five characters that make up the landing pad.
   Press [ESC] and follow the screen prompts to save your screen to disk or cassette for future play. Your screen design will replace one of the original game screens. When you choose the screen you want to replace, the bottom of the screen will clear.
   Then you can watch as the computer writes the program lines that will create your new landing site. This is done with the Atari's forced read mode. (POKE location 842 with 13 and the computer will accept information from the screen as if it were typed from the keyboard.) To play your customized landing simulation, press [START].

Daniel Deighan is a host-bartender at Del's Restaurant in Pittsburgh, PA as well as assistant sysop of Nightlife BBS at (412) 343-0740.

Listing 1 LANDER.BAS
Listing 2 LINES.LST (Not needed)