ZX81 Programs


Read about, play, run, or list games, animations, and more. These are my programs from the ’80s to today.

ZX81 Program Listing

MISSILE DEFENSE*SLR1983 (md.p)


SYSTEM VARIABLES

PROG  : 16509
D-FILE: 17452
VARS  : 18245
E-LINE: 18246
STKBOT: 18246
STKEND: 18246


LEGEND

A means INVERSE A
A means GRAPHICS A
PRINT means treat as KEYWORD P


PROGRAM LISTING

  10 REM MISSILE DEFENSE*SLR1983
  20 PRINT ">>> MISSILE DEFENSE 
<<<",,,"TYPE IN Z FOR LEFT, X FO
R RIGHT,AND . FOR FIRE."
  22 PRINT AT 21,0;"6Q WWQ QW66W
W6Q  WW6QQ W66QQW W6";
  25 LET S=0
  27 LET D=.1
  30 LET A=15
  40 LET B=INT (20*RND)+5
  50 LET C=4
  60 PRINT AT C,B;" "
  70 PRINT AT 20,A;" A "
  80 LET C=C+D
  90 LET D$=INKEY$
 100 LET A=A-(D$="Z" AND A>0)+(D
$="X" AND A<29)
 110 IF C>=20 THEN GOTO 170
 120 IF D$="." THEN GOTO 150
 130 GOTO 60
 150 IF A+1=B THEN GOTO 220
 160 GOTO 60
 170 PRINT AT 20,A+1;"Y";TAB 0;"
QERWEETTYQT12WTTYEE47TWWQTTQYW1R
";
 180 PRINT AT 17,B-2;"E6664";AT
18,B-2;"R   E";AT 19,B;" ";AT 20
,B-2;"4   E"
 190 PRINT AT 1,0;"SCORE: ";S;
TAB 0;"GAME OVER***PRESS A KEY T
O START                         
      "
 200 IF INKEY$="" THEN GOTO 200
 205 CLS
 210 RUN
 220 FOR X=INT (C+.5) TO 4 STEP
-1
 230 PRINT AT X,B;"H";AT X,B;" "
 240 NEXT X
 250 LET S=S+100
 260 IF D<.8 THEN LET D=D+.05
 270 GOTO 40
 300 SAVE "MD"
 310 RUN