0 PRINT"[147]":POKE53280,0:POKE53281,6:POKE646,1
1 REM
2 REM  * RADIOACTIVE DECAY *
3 REM    RUPERT REPORT #22
4 REM
5 REM MONTE CARLO SIMULATION OF A
6 REM TWO-PRODUCT DECAY CHAIN
7 REM
10 TTL=100   :REM INITIAL NUMBER
20 SF=22/TTL :REM PLOT SCALE FACTOR
30 ND=2  :REM NUMBER OF DAUGHTERS
40 DIM NUC(TTL)
100 REM  DECAY CONSTANTS
110 DC(0)=.2
120 DC(1)=.05 :REM FIRST DAUGHTER
130 DC(2)=0   :REM STABLE ISOTOPE
140 M(0)=TTL  :REM INITIAL AMOUNT
150 PRINT CHR$(147)"  =-= RADIOACTIVE DECAY =-="
160 FOR T=1 TO 20
170 GOSUB 400 :REM <<< GOSUB 500 TO PLOT
180 FOR N=1 TO TTL
190 IF RND(0) > DC(NUC(N)) THEN 220
200 K=NUC(N) : NUC(N)=K+1
210 M(K)=M(K)-1 : M(K+1)=M(K+1)+1
220 NEXT N
230 NEXT T
240 POKE 214,23 : PRINT
250 POKE 211,12
260 PRINT"=PRESS A KEY TO CONTINUE==>";
270 GET A$ : IF A$="" THEN 270
280 GOTO 150
390 END
395 REM --- PRINT VALUE ROUTINE ---
400 PRINT TM ">>",
410 FOR J=0 TO ND
420 PRINT M(J),:NEXT J
430 TM=TM+1
440 RETURN
495 REM
499 REM ---- PLOT ROUTINE ----
500 FOR J=0 TO ND
510 Y=M(J) : S$=RIGHT$(STR$(J),1)
520 ROW%=22-SF*Y : COL%=2*T-2
530 IF ROW%>23 THEN ROW%=23
540 IF ROW%<=0 THEN ROW%=0
550 IF COL%>38 THEN COL%=38
560 IF COL%<0 THEN COL%=0
570 POKE 214,ROW%: PRINT
580 POKE 211,COL%: PRINT S$
590 NEXT J : RETURN