0 REM << RR22-1 >>
1 REM
2 REM -- MOLECULAR MOTION --
3 REM    RUPERT REPORT #22
4 REM
6 REM MOVEMENT OF MOLECULES FROM ONE
7 REM COMPARTMENT TO ANOTHER
8 REM
9 :REM  TOTAL # AND # ON LEFT SIDE:
10 TTL=480 : NL=480
15 L1$=CHR$(157):L$=" "+L1$+L1$+" "
20 KK=1 : K1=1024 : K2=40
30 K3=32 : K4=81  :REM BLANK & MOLECULE
35 :REM  CLEAR SCREEN AND SET COLOR:
40 POKE 53281,0 : PRINT CHR$(147)
50 POKE 53281,1 : PRINT CHR$(144)
55 :REM  PUT 480 MOLECULES ON LEFT:
60 FOR Y=1 TO 24 : FOR X=0 TO 19
70 POKE K1+X+K2*Y,K4 : NEXT : NEXT
75 :REM  ====  MAIN LOOP ====
80 RL=NL/TTL :REM RELATIVE # ON LEFT
90 RN=RND(0) :REM RANDOM NUMBER
100 IF NL=480 AND KK=-1 THEN 270
110 IF RN<RL THEN PL=K3: PR=K4:GOTO 130
120 PL=K4 : PR=K3
130 X=INT(RND(0)*20):Y=INT(RND(0)*24)+1
135 REM   MEMORY LOCATIONS TO POKE
140 ML=K1+X+Y*K2
150 MR=K1+(20+X)+Y*K2
160 GET A$ : IF A$<>"" THEN 270
165 REM  FIND LOCATION TO 'UNPOKE'
170 IF PEEK(ML)<>PL THEN 210
180 Y=Y+1 : IF Y<25 THEN 140
190 Y=1 : X=X+1 : IF X<20 THEN 140
200 X=0 : GOTO 140
210 IF PL=K3 THEN NL=NL-KK : GOTO 230
220 NL=NL+KK
230 NR=TTL-NL : T=T+1
240 POKE ML,PL : POKE MR,PR
250 PRINT CHR$(19);NL;TAB(17);"T=";KK*T;L$;TAB(34);NR;L$
260 GOTO 80
265 REM   REVERSE THE ARROW OF TIME
270 KK=-KK : TEMP=K3 : K3=K4 : K4=TEMP
280 T=0 : GOTO 80