10 REM  PI CALCULATION WITH SPIGOT
  100 N=100: REM MAX N=260 TO AVOID OVERFLOW
  110 LEN=(10*N)/3
  120 J=0:K=0:Q=0:NINES=0:PREDIGIT=0
  125 DIM A(LEN)
  130 REM  VARIABLES FOR THE SUB
  140 RESULT=0:I=0:X=0
  200 REM  MAIN
  210 FOR J=1 TO LEN:A(J)=2: NEXT J
  220 REM  START WITH 222...
  230 NINES=0
  240 PREDIGIT=0
  250 REM  FIRST PREDIGIT =0
  260 FOR J=1 TO N
  270 I=N-J: GOSUB 1000:Q=RESULT
  275 A(1)=Q MOD 10
  280 Q=Q/10
  290 IF Q=9 THEN NINES=NINES+1
  300 IF Q=10 THEN GOSUB 800
  310 IF (Q<>9) AND (Q<>10) THEN GOSUB 900
  320 NEXT J
  330 PRINT PREDIGIT
  340 END
  800 PRINT PREDIGIT+1;
  805 IF NINES=0 THEN GOTO 820
  810 FOR K=1 TO NINES: PRINT 0;: NEXT K
  820 PREDIGIT=0:NINES=0
  830 RETURN
  900 PRINT PREDIGIT;
  910 PREDIGIT=Q
  920 IF NINES<>0 THEN GOSUB 950
  930 RETURN
  950 FOR K=1 TO NINES: PRINT 9;: NEXT K
  960 NINES=0
  970 RETURN
 1000 I=I*10/3+16
 1010 IF I>LEN THEN I=LEN
 1020 RESULT=0
 1030 REM  REPEAT
 1040 X=10*A(I)+RESULT*I
 1050 RESULT=X/(2*I-1)
 1060 A(I)=X MOD (2*I-1)
 1070 I=I-1
 1080 IF I>0 THEN GOTO 1040
 1090 RETURN