Astro

Lost in deep space and caught in an asteroid storm, you move your ship left and right along the bottom of the screen and fire at the asteroids falling towards you. Each asteroid destroyed is worth 50 points and each one missed costs 10, and you have only one life. Control is with O and P and SPACE to fire, or a joystick. A menu, worked by joystick or keyboard, offers Play Mode, Demo Mode, Instructions and Quit.

Astro is by Eric Boisvert and was published on the September 1986 tape of Byte Power (#63045); the magazine gives a loading time of one minute. A sequel, Weird Balls (Astro II), appeared in the February 1988 issue (#59215).

Program Analysis

The tape file is one 6,281-byte BASIC program: the game is machine code and character data in a REM at line 0, with the instructions, menu and credit text stored as plain strings. Line 1 starts it with RANDOMIZE USR 28624 and returns to a cold start with RANDOMIZE USR 0 when the game is quit. The code is not decoded here.

Notable Techniques

• Line 1 checks PEEK 23681: Byte Power told readers to POKE 23681,0 before loading a program so that it stops after loading and can be saved with line 9999 as a personal backup; otherwise the program starts the code.

Appears On

Byte Power September 1986

Tape-based magazine. The September 1986 issue (Issue 2) of Byte Power, the monthly TS2068 tape magazine created by Eric and Kristian Boisvert of Pickering, Ontario, in May 1986.

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Astro

You are trapped in an asteroid storm in deep space. To survive you must destroy the asteroids or, at least, avoid them!

Image Gallery

Note: Type-in program listings on this website use ZMAKEBAS notation for graphics characters.