10 DEFFNS="Pat2"
   20  REM Program name "PATTERN"
   30  REM Written by M.L.W. 4/6/1988
   40  REM Article by Keith Devlin
   50  REM Computer Guardian 2/6/1988
   60  REM Sent to 8BIT SOFTWARE 16/2/94
   70 REM Fiddled with by CJR 21.2.94
   80  MODE0
   90 VDU23;8202;0;0;0;
  100 N=1:D=1
  110 ONERROR
  120 PRINT'"Change the D and N values using ZXCV."
  130 PRINT"Dump the screen (When finished) by pressing D."
  140 PRINT"Pressing any other key cancels dump."
  150 PRINT'"ESCAPE to return here."'
  160 INPUT"Val 1? 1-359 RETURN=no change. "D%:IF D%>0 IF D%<360 D=D%
  170 INPUT"Val 2? 1-359 RETURN=no change. "N%:IF N%>0 IF N%<360 N=N%
  180 REPEAT
  190 REPEAT
  200 D%=0
  210 CLS
  220 PRINTTAB(0,0);STR$D;" Z-Down X-Up"'STR$N;" C-Down V-Up"
  230 *FX21
  240 COLOUR 1
  250 VDU 19,1,RND(6),0,0,0
  260 oldX=0:oldY=0:A=0
  270 VDU 29,640;512;
  280 MOVE oldX,oldY
  290 REPEAT
  300 A=A+D
  310 IF A>360 A=A MOD 360
  320 X=((N*A)MOD360)*0.01745
  330 R=SIN(X)
  340 T=A*0.01745
  350 newX=R*SIN(T) :newY=R*COS(T)
  360 newX=500*newX :newY=500*newY
  370 DRAW newX,newY
  380 Z%=INKEY0
  390 IFZ% <>-1 PROCinput
  400 UNTIL A=360
  410 IF Z%=-1 OR Z%=68 VDU19,1,7,0,0,0:FORDEL=1TO1000:NEXT
  420 IF D%:OSCLI"GDUMP":REM YOUR DUMP ROUTINE HERE
  430 IF Z%=-1 D=D+1
  440 UNTILD=360
  450 D=1
  460 IF Z%=-1 OR Z%=68 N=N+1
  470 UNTILN=360
  480 END
  490 DEFPROCinput
  500 IFZ%=68 D%=1 ELSE D%=0
  510 IFZ%=90 IF D>1 D=D-1
  520 IFZ%=88 IF D<358 D=D+1
  530 IFZ%=67 IF N>1 N=N-1
  540 IFZ%=86 IF N<358 N=N+1
  550 IF Z%<>68 A=360
  560 ENDPROC