10 REM IBM
20 REM BANK: deposits, debt account, and loans
30 CLS
40  SCREEN 1, 0: COLOR 15, 0
50  LINE (0, 0)-(319, 180), 2, B
60  R = 105000!
70  DS = 100000!
80  B = 1000000!
90  D = 10000
100 IN = .05
110 T0 = 1
120 B0 = .00001
130 D0 = .00001
140 DT = .5
150 K1 = .001
160 K2 = .05
170 DB = R - K1 * B + DS - K2 * D - D * IN
180 DD = DS - K2 * D
190 B = B + DB * DT
200 D = D + DD * DT
210 T = T + DT
220  PSET (T * T0, 180 - B * B0), 1
230  PSET (T * T0, 180 - D * D0), 3
240  IF T * T0 < 319 GOTO 170
250 LOCATE 2, 2: PRINT "Bank.bas": SLEEP: SLEEP
260 END