ZX-81 Ground Strike
by Phillip Tyler
from Your Computing April 1984, Page 84

ZX-81 GROUND STRIKE

Your terrain-hugging mission to destroy ground targets means weaving a
perilous path through the heavy flak in Phillip Tyler's machine-code game.

THIS PROGRAM will run only on the 1K ZX-8l, and so RAM packs must be
disconnected before the program is loaded.

After LOADing the program, type in, as direct commands:

	RAND
then:
	RUN

If everything is running happily, your jet should be resting on a flat area
of landscape ready for take off, a hilly landscape should be moving towards
you, and the flak should be moving across the screen. If your aeroplane
collides with the hillside it will explode, stopping the program.

Keys l,2,3,4,5,Q,W,E,R, and T move your plane up, and keys A,S,D,F,G,Z,X,C,
and V move it down. Keys 6,7,8,9,0,Y,U,I,O,P drop a bomb from the jet.
Shooting a base represented by an A - earns you 10 points.

To speed the game up, POKE address 16627 with a number between 1 and 15; to
slow the game down, POKE address 16627 with a number between 16 and 255.