10  REM  IBM
20  REM NZ (History of New Zealand economy)
30 REM Time zero is the year 1852 with little export.
40  CLS
50  SCREEN 1, 0: COLOR 15, 0
60  LINE (0, 1)-(319, 180), 3, B
65 FLAG = 0
70  N = 50
80  A = 10
90  S = 1
100 J = 1.1
110 TN = 1
120 F = 25000
130  K0 = .5
140 K1 = 1.5
150 K2 = .15
160 K3 = .05
170 K4 = 1.4
180 K5 = .0109
190 K6 = 0
200 K7 = .00001
210 K8 = .006
220 K9 = .02
230 RP = 0
240 X1 = .0132
250 X2 = .00013
260 X3 = .00255
270 X4 = 48
280 X5 = 0
290 T0 = 1.5
300 DT = 1
310 N0 = 1
320 S0 = 2
330 A0 = .002
340 F0 = .00625
350 I = J / (1 + K0 * N)
360 DF = -X5 * F
370 DN = TN - K3 * N - K4 * N * I + X2 * A
380 DS = K1 * I * N - K2 * S - K6 * S - K7 * S * A
390 DA = X5 * F + (X4 * S + X3 * A) * RP + K8 * S * A - K9 * A - K5 * A - X1 * A - X3 * A
400 A = A + DA * DT
410  IF A < 1 THEN A = 1
420 N = N + DN * DT
430  IF N < 0 THEN N = 0
440 S = S + DS * DT
450  IF S < 1 THEN S = 1
460 F = F + DF * DT
470  IF F < 0 THEN F = 0
480 T = T + DT
490  IF Z = 1 GOTO 510
500  IF T > 60 THEN RP = 7: X4 = 32: K6 = .6: REM year 1912; Increase Lamb export
510  IF T > 120 THEN RP = 2 - .03 * (T - 120): REM year 1972; Jump in oil prices
520 X5 = X5 + .0001
530  PSET (T * T0, 180 - N * N0), 1
540  PSET (T * T0, 180 - S * S0), 2
550  PSET (T * T0, 180 - A * A0), 3
560  PSET (T * T0, 180 - F * F0), 1
570 LINE (127 * T0, 0)-(127 * T0, 180), 2
580 LINE (60 * T0, 0)-(60 * T0, 180), 2
590  IF T = 127 GOTO 610
600  IF T * T0 < 319 GOTO 350
610  LOCATE 2, 2: PRIN T "Nz.bas"
620 IF FLAG = 1 THEN SLEEP: SLEEP: END
625 FLAG = 1
630 Z = 1
700  GOTO 350