10 REM IBM: WORLD
20 REM  (Model of world trends)
30 CLS
40 SCREEN 1, 0: COLOR 0, 1
50 LINE (0, 0)-(319, 180), 3, B
60 S = 60000!
70 S0 = 800!
80 Q = 1
90 Q0 = 2
100 F = 0
110 F0 = 6
120 I = 120
130 T0 = 2.2
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  IF T = 300 THEN F = 1000
230 REM ASSETS ARE PURPLE
240 PSET (T / T0, 180 - Q / Q0), 2
250 REM SOIL & WOOD ARE BLUE
260  PSET (T / T0, 180 - S / S0), 1
270 REM FUEL IS WHITE
280 IF T < 300 THEN PSET (T / T0, 12), 3
290  PSET (T / T0, 180 - F / F0), 3
300 D1 = K1 * S * F * Q + K2 * S * Q - K3 * Q + K8 * S
310 D2 = I - K7 * S - K5 * S * F * Q - K6 * S * Q
320 D3 = -K4 * S * F * Q
330 Q = Q + D1
340 S = S + D2
350 F = F + D3
360 T = T + 1
370 IF T < 319 * T0 GOTO 220
375 BEEP: SLEEP
380 END