1   REM CALCULATE PI  /BH,1976
10  LET D=T=U=N=1
20  LET U=U*N
30  LET D=2*D*N+D
40  LET S=T
50  LET T=T+U/D
60  PRINT "N=" N; "PI=" 2*T
70  IF S=T THEN 100
80  LET N=N+1
90  GOTO 20
100 END