10 REM IBM
20 REM STWORLD: STATE-WORLD, State model driven by world model
30 CLS
40 SCREEN 1, 0: COLOR 15, 0
50 LINE (0, 0)-(319, 180), 3, B
60 LINE (O, 80)-(319, 80), 2
70 I = 120
80 J = 2
90 S = 60000!
100 Q = 1
110 W = 10
120 F = 0
130 U = .1
140 K1 = 1E-09
150 K2 = .0000005
160 K3 = .04
170 K4 = 2E-09
180 K5 = 1.8E-08
190 K6 = .000018
200 K7 = .0018
210 K8 = .00001
220 L = .1
230 L1 = .00016
240 L2 = .000266
250 L3 = .17
260 L4 = .01
270 L5 = .006
280 L6 = .04666
290 S0 = .001
300 Q0 = .3
310 F0 = .08
320 DT = 1
330 T0 = .45
340 U0 = 3
350 W0 = 3
360 REM WORLD IS TOP OF SCREEN
370  IF T = 300 THEN F = 1000
380 PSET (T * T0, 80 - Q * Q0), 2
390  PSET (T * T0, 80 - S * S0), 1
400  PSET (T * T0, 80 - F * F0), 3
410  PSET (T * T0, 180 - W * W0), 1
420 PSET (T * T0, 180 - U * U0), 3
430 D1 = K1 * S * F * Q + K2 * S * Q - K3 * Q + K8 * S
440 D2 = I - K5 * S * F * Q - K6 * S * Q - K7 * S
450 D3 = -K4 * S * F * Q
460 D4 = J - L1 * Q * U * W - L3 * W - L5 * W
470 D5 = -L * U + L2 * U * Q * W + L4 * W - L6 * U
480 Q = Q + D1 * DT
490 S = S + D2 * DT
500 F = F + D3 * DT
510 W = W + D4 * DT
520  IF W < .1 THEN W = .1
530 U = U + D5 * DT
540 T = T + DT
550  IF T * T0 < 319 GOTO 360
560  LOCATE 2, 2: PRINT "Stworld.bas": SLEEP: SLEEP
570 END