ZX Computings - OpenLibra

Make
the
most
of IK
Chopper Squad
R Morland and M Frobisher of
Chalfont St Giles sent us this
great little program for a 1K
ZX81. You are in charge of a
cleverly-drawn helicopter. The
"6" and "1" keys move your
chopper up and down, while
the "F" key fires.
Your helicopter flies in from
the left of the screen, buffeted
by random crosswinds, and air
pockets. You use the "6" and
"7" to keep your craft in flight,
and from time to time, press
"F" to obliterate an asterisk or
two underneath you. Due to
lack of space, the program is
not perfect, as the helicopter
from time to time leaves an
'image' of itself behind if it
lands on the base, then takes
off again. You may well want to
work on this problem. The
variable S is your score.
1K ZX81 Programs
1 10
* * * * * * * * * * * * * * * * * * * * * 120
130
140
30
150
10 LET X = I 1 6 0
2 0 LET H = LL? 1 7 0
30 LET S = X — X 1 8 0
40 LET B=X 190
50 FOR R=5 TO 25 200
60 PRINT BT IS/P;"®" 210
70 PRINT RT 14- ,«>"*" 220
3 0 NEXT R 230
90 LET R =X-X 240
100 LET H=H* T INKEV $ = **6" - » INKEV 250
$ = " 7 "J
260
IF INKEV$="F" THEM GOTO 2
PRINT RT H-X,B;"--»--"
PRINT RT H^B;'*""*®"
IP H>=14 OR H .6 THEN LET H=H*X
LET B=0-T-X
LET R=R + X
IF R>70 THEN GOTO 260
GOTO 100
PRINT RT 14-,B," "
L E T 5 = S 4 X
GOTO 100
PRINT S
30