Classic Computer Magazine Archive COMPUTE! ISSUE 25 / JUNE 1982 / PAGE 30

Outpost

Tim Parker
Kanata, Ontario

This strategy game will run as presented on any Commodore computer. A version for the Atari is included separately. The Commodore version will also run on an Apple with the changes noted at the end of the article. Originally written for the VIC, it has no sound effects (to save memory). These were added to the Atari Version.

The object of Outpost is to survive. You are placed in an immovable outpost, armed with torpedoes, main and secondary energy armaments, and a targeting computer. Your opponents come in three sizes, labelled SML (small), MDM (medium) and HVY (heavy). Their objective is to overrun you, or destroy you by knocking out your armaments, computer, or energy supply.

When RUN, the screen gives you quite a lot of information. Your status is displayed to the right center, where values for ENGY (energy), COMP (computer), MAIN (main armament), SECN (secondary armament), TORP (torpedoes), and VP (victory points) are displayed. Energy is rated from zero to ninety-nine. If the energy drops to zero, you lose the game. Computer efficiency, and both main and secondary armaments, are rated as a percentage of capability. Ninety-nine is maximum.

If the computer falls to zero, you have lost all defensive capabilities, and lose the game. If either or both armaments fall to zero, they cannot be fired until recharged by a supply ship. Five torpedoes are supplied at the beginning of the game. A maximum of nine can be stored in the outpost at any time. Victory Points is your score. For each light enemy ship destroyed, one victory point is awarded; similarly, two for medium, and three for heavy ships.

The top of the screen shows the enemy. Up to four are active at a time. Each enemy ship is referenced by a number on the "radar screen" at center left. The index above gives the DIST (distance), PROB (hit probability), and ENGY (energy) of the enemy. The hit probability is a function of both enemy distance and your computer efficiency. If enemy energy falls to zero it is destroyed, and victory points are awarded.

When playing, the computer will give you a "Weapon" prompt. This requires an input of T(orpedo), M(ain), or S(econdary) for the different weapons. C can be entered to recharge your batteries, and the energy of the outpost will increase when employed, to a maximum of 99. If a weapon is being fired, the prompt "TARGET NO" appears, requiring a value of one to four, depending on the enemy number.

After your turn, the computer will move some of the enemy ships, and some will fire at you. They have a hit probability that is a function of their energy. Damage to energy, computer, or armaments may result.

Occasionally, a supply ship wanders onto the screen. This is shown by a white "S". If it reaches you successfully, it recharges energy, main and secondary armaments to full power, and adds up to five torpedoes. Since a maximum of nine can be held at one time, any extras are lost. Note that the supply ship does not recharge your computer. The supply ships can be destroyed if an enemy lands on top of them.

As might be expected, a hit on an enemy ship will decrease its energy. The amount of damage done is proportional to the type of enemy ship; the heavy ships are harder to destroy than mediums and lights. The type of weapon fired also affects damage. On an efficiency scale, torpedoes, main and secondary armament are approximately 9:6:4 in damage ratios. A few trial games quickly gives a feel for this.

High scores are not always easy to get. If a score of twenty is achieved, you are very good. Forty is excellent. Sixty is almost impossible, unless you're extremely lucky.

Strategy

The light ships are the most easily destroyed, but they do the least damage to you. If a heavy ship appears, try to get it fast. If an enemy gets within two moves of you, hit it hard. If it lands on you, you are destroyed. Also, protect your supply ships. They are needed and they are easily destroyed by the enemy.

As the computer efficiency rating drops, the hit probability also drops. With low computer values, you'll find that you have to wait for the enemy to get close before wasting shots. Torpedoes shouldn't be wasted, especially on low probability shots. If you get a few enemy ships on the screen at once, pick them off one at a time if possible to try and avoid concentrated fire. If you have four heavy ships bearing down on you, it's wisest to panic. If no enemy ships are on the screen, charge your batteries.

The Program

The program is divided into several blocks:

lines 0-999 Control section
1000-1999 Screen display
2000-2999 Refuel routine
3000-3999 Enemy movement
4000-4999 Enemy fire
5000-5999 Enemy ship & Supply ship appearances
6000-6999 Weapons and firing routine
9500-9999 Destroyed routine.

When RUN, the program loops through each section, beginning with your fire routine, enemy fire and movement, new ships, and the screen routine. This is controlled by line 500.

The odds of a ship appearing are given in lines 5005 and 5010. The four ships are listed as subscripts of ET(x), with a value of one for light, two for medium, and three for heavy ships. ET(5) is the supply ship, and has a value of five if one is on the screen, and zero otherwise. EH(x) is the ship's hit probability, given by line 40, and ED(x) is the distance, given in line 30. To change the difficulty level of the game, change the values of the number following "FNA(x)" in lines 5005 and 5010. If a ship is scheduled to appear, line 5110 chooses the type. Light are the most probable.

The "radar screen" is generated by section 1500-1700 using an individual coordinate system. EX(x) and EY(x) define each enemy ship location. This is a slow method for generating the display, but offers the best memory saving.

GET statements are used throughout to avoid the inevitable RETURN hit.

Notes For Apple Owners:

Outpost is not too hard to adapt to the Apple since it is primarily a straightforward text display. The only problems are in the formatting of the display. Follow the suggestions given in COMPUTE!'s Listing Conventions, e.g. replace [CLEAR] with ‘HOME’, [LEFT] with CHR$(8), etc. Ignore all the VIC color controls such as WHT, CYN, BLK, etc. You may want to replace lines like 1690:

1690 PRINT "[HOME][6 DOWN]"

with

1690 VTAB 6

In line 1305, the underlined D's represent dashes, and the underlined Q in line 1630 is a "ball character." You can put whatever you like there, perhaps an asterisk.