AIR-RAID

by H.T. Davis

from ZX Computing Aug/Sep.1983



AIR RAIDERS



More overhead excitement in this Spectrum program, courtesy

of Mr HT Davis of Hereford.





This program differs a little bit from the normal 'war time'

simulation games in that the shells actually follow a

parabolic trajectory. The equation used to work out their

motion is calculated in line 75 and simulates a projectile

under gravity.





What goes up ...



The initial velocity and angle of projection can either be

selected by the player (mode x) or by the computer (mode z).

The aim of the game is to destroy the overhead aircraft,

launched ICBMs and the ICBM base; the ICBMs and their base

must be destroyed using shells and the aircraft should be

destroyed using rockets. The game stops either after eight

cycles or if you accidentally destroy an allied aircraft

(you can spot them because they're blue!).



Full instructions are included in the program, including

when one can fire a shell or a rocket. The program occupies

virtually all of the 16K memory.





A variable situation



The variables used in this program are:



g	- The number of game cycles.

p	- The game mode.

s	- The score.

r	- The rocket drive.

v	- The rocket control.

w	- The random element in the aircraft and ICBM drive.

x	- The aircraft and ICBM drive.

(x,y)	- The shell trajectory pixels.

(q,m)	- The shell trajectory co-ordinates.

z	- The shell control.

U	- The shell launch velocity (V on display).

A	- The shell launch angle.





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Another Fine Product transcribed by:

Jim Grimwood, Weardale, England

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