10 REM ****************************
20 REM *   NEWTON-ITERATION       *
30 REM * 1987 BY STEFAN VILSMEIER *
40 REM ****************************
50 :
60 POKE53280,0:POKE53281,0
70 INPUT "[147]STARTWERT X0    ";X0
80 XM=X0:PRINT
90 :
100 REM ****** FUNKTION ************
110 :
120 DEF FND(X)=X^2-1
130 DEF FNE(X)=2*X     :REM ABLEITUNG
140 :
150 REM ***************************
160 REM *   HAUPTSCHLEIFE         *
170 REM ***************************
180 :
190 IF FNE(XM)=0 THEN PRINT "GEHT NICHT!":END
200 X=X-FND(XM)/FNE(XM)
210 I=I+1:PRINT I,X
220 IF ABS(X-XM)>.0005 THEN XM=X:GOTO 190
230 PRINT "FERTIG!"