Classic Computer Magazine Archive COMPUTE! ISSUE 36 / MAY 1983 / PAGE 48

One On One

Chris York

"One On One" is easy to learn, but not easy to master. Written originally for the Atari, it has been translated for VIC, 64, and Apple. The VIC and 64 versions include two skill levels and a suggestion for changing the object of the game.

In "One On One," two players go head to head in an attempt to knock down the wall their opponent is protecting.

The Atari version can be played with joysticks, plugged into control ports one and two, or with paddles, plugged into port number one. In the game, player one tries to protect the wall at the top of the screen, and player two defends the wall at the bottom.

The player's paddle (horizontal line closest to the middle section of the screen) is used to intercept the ball before it hits his wall and destroys a section. When the ball hits either player's paddle, it bounces toward the opponent's wall. En route, the flight of the ball may be changed or impeded by barriers or additional sections of wall which serve to make the game faster and more exciting.

Eventually, one or both players will lose enough wall so that the ball can go through it. The first player to get the ball past his opponent's wall wins the game and receives an appropriate victory message.

One On One is easy to learn and challenging. You'll keep coming back to play it again and again.

A multicolored character mode is used to brighten up the screen in the Atari version of "One on One." (Other versions similar.)

VIC Version

The VIC version uses game paddles plugged into the control port. It has two skill levels. At level one, all ball movement is at a 45 degree angle with respect to the X and Y axis. Level two allows the players to double the horizontal increment of the ball by striking it with a moving paddle. The subroutine from lines 160 to 220 determines if the paddle has changed from its last position. If the paddle position changes just before the ball strikes it, then the resulting horizontal motion of the ball becomes twice as fast. The vertical increment of the ball, however, always stays the same. Either player can slow the ball to the usual diagonal motion by allowing the ball to strike a stationary paddle.

The wall that each player must defend is generated with random brick colors in lines 420 to 440. The game will look different each time it is played.

If you become truly proficient at One On One, you might change the game so that the object is to break through the wall behind your paddle. This speeds up the action considerably, as you attempt to maintain control of the ball. Giving control of the ball to your opponent, of course, allows him to destroy his wall and defeat you even sooner.

CBM-64 Version

The Commodore 64 version of One On One is designed to be played using two joysticks. Since barriers are placed in symmetrical positions in the central portion of the screen, the ball may rebound four or five times before reaching an opponent. This provides for a more challenging defensive strategy and a faster moving game. If you would like to adapt this program for use with paddles, substitute these lines:

11 AL = (36-(INT(F2/8.5
   THEN 17
19 F2 = PEEK(54297):GOTO10
51 AR = (36-(INT(F1/8.5)+3))
   THEN 57
59 F1 = PEEK(54298):GOTO 50

Apple Version

On the Apple, One On One is played with the paddles and has two skill levels. At level one, all ball movement is strictly 45 degrees with respect to the X and Y axis. After a short period of play, you'll probably be ready to move on to level two, where the ball angle can be altered.

At level two, the flight of the ball can be changed from the usual diagonal motion by moving the paddle just prior to the moment the ball strikes it. If this is successfully accomplished (as detected in lines 18 to 28), the X increment of the ball is doubled so that the ball moves twice as fast horizontally. Vertical ball movement, on the other hand, remains the same. In order to return to normal ball motion, the ball must strike a stationary paddle.

An especially pleasing feature of the Apple version is the random choice of wall colors each time a new game is played. This is carried out in the short subroutine at line 30.

A different sort of game can be played if you try to break through the wall behind you rather than defend it. The player who maintains control of the ball longer will ultimately break through his wall more quickly.