100 PROGRAM "PI.bas"
110 LET N=100 ! Nuber of digits
120 LET LN=INT(10*N/3)+16
130 DIM A(LN)
140 LET PD,N9=0:LET ND=1
150 FOR J=1 TO LN
160   LET A(J-1)=2
170 NEXT
180 FOR J=1 TO N
190   LET Q=0
200   FOR I=LN TO 1 STEP-1
210     LET X=10*A(I-1)+Q*I
220     LET A(I-1)=X-(2*I-1)*INT(X/(2*I-1))
230     LET Q=INT(X/(2*I-1))
240   NEXT
250   LET A(0)=Q-10*INT(Q/10)
260   LET Q=INT(Q/10)
270   SELECT CASE Q
280   CASE 9
290     LET N9=N9+1
300   CASE 10
310     LET D=PD+1:CALL WRITE
320     IF N9>0 THEN
330       FOR K=1 TO N9
340         LET D=0:CALL WRITE
350       NEXT
360     END IF
370     LET PD,N9=0
380   CASE ELSE
390     LET D=PD:CALL WRITE
400     LET PD=Q
410     IF N9<>0 THEN
420       FOR K=1 TO N9
430         LET D=9:CALL WRITE
440       NEXT
450       LET N9=0
460     END IF
470   END SELECT
480 NEXT
490 PRINT STR$(PD)(1)
500 END
510 DEF WRITE
520   IF ND=0 THEN
530     PRINT STR$(D)(1);
540   ELSE IF D<>0 THEN
550     PRINT STR$(D)(1);".";
560     LET ND=0
570   END IF
580 END DEF