10 REM IBM PC
20 REM MACROEC (Macroeconomics)
30 REM Initial run is with unlimited resources. Then type CONT for run with renewable resources.
40 CLS
50  SCREEN 1, 0: COLOR 15, 0
60  LINE (0, 0)-(319, 180), 3, B
70 X = 0
80 REM SCALING FACTORS
90 DT = .1
100 T0 = 10
110 Y0 = 3
120 KZ = 3
130 REM  COEFFICIENTS
140 K0 = .1
150 K1 = 1
160 K2 = .05
170 K3 = 1
180 K4 = .011
190 K5 = .1
200 K6 = .00011
210 REM SOURCES
220 J = 100
230 E = 10
240 REM INITIAL CONDITIONS
250 Y = 10
260 S = K5 * Y
265 I = S
268 C = Y - S
280 K = 10
300  REM  PLOTTING
310  IF Y * Y0 > 180 GOTO 330
320  PSET (T * T0, 180 - Y * Y0), 1
330  IF K * KZ > 180 GOTO 530
340  PSET (T * T0, 180 - K * KZ), 2
350  REM  EQUATIONS
370  IF X = 0 GOTO 390
380  IF X = 1 GOTO 405
390 DK = K3 * I - K6 * E * C * K - K2 * K
400 PR = K4 * C * K * E: GOTO 412
405 R = J / (1 + K0 * K * C): REM RESIDUAL RESOURCES AVAILABLE
410 PR = K4 * C * K * R
411 DK = K3 * I - K6 * R * C * K - K2 * K
412 Y = K1 * PR
414 S = K5 * Y
416 I = S
417 C = Y - S
440 K = K + DK * DT
450 IF K < .00001 THEN K = .00001
510 T = T + DT
520  IF T * T0 < 319 GOTO 300
530   LOCATE 2, 2: PRINT "Macroec.bas": SLEEP: SLEEP: END
540 REM Type CONT to rerun with renewable resources
550 X = 1
560 T = 0
570 Y = 0
575 K = 0
580 GOTO 100