       IDENTIFICATION DIVISION.
       PROGRAM-ID. PI-CALC.
       AUTHOR. PF/TR.
      *
       ENVIRONMENT DIVISION.
       CONFIGURATION SECTION.
       OBJECT-COMPUTER. MDS-800.
       SPECIAL-NAMES. CONSOLE IS CRT.
      *
       DATA DIVISION.
       WORKING-STORAGE SECTION.
      *
       01  SCREEN PIC X(1920).
      *
       01  DI-1 REDEFINES SCREEN.
           02 FILLER PIC X(160).
           02 DI-TX1 PIC X(160).
           02 DI-TX2 PIC X(13).
           02 DI-TERM PIC X(15).
           02 FILLER PIC X(136).
           02 DI-TX3 PIC X(6).
           02 DI-PI PIC X(15).
           02 FILLER PIC X(1415).
      *
       01  DI-2 REDEFINES SCREEN.
           02 FILLER PIC X(333).
           02 DI-TERM2 PIC X(15).
           02 FILLER PIC X(142).
           02 DI-PI2 PIC X(15).
           02 FILLER PIC X(1415).
      *
       01  WORK-AREA.
           02 PI PIC S9V9(14).
           02 TERM PIC S9V9(14).
           02 W PIC S9V9(14).
           02 N PIC 9999.
           02 N1 PIC 9999.
           02 N2 PIC 9999.
           02 ED PIC -9.9(12).
      *
       01  CONSTANTS.
           02 TX1 PIC X(17) VALUE "CALCULATION OF PI".
           02 TX2 PIC X(12) VALUE "NEXT TERM IS".
           02 TX3 PIC X(5) VALUE "PI IS".
      *
       PROCEDURE DIVISION.
       LA-START.
           DISPLAY SPACE.
           MOVE SPACE TO SCREEN.
           MOVE TX1 TO DI-TX1.
           MOVE TX2 TO DI-TX2.
           MOVE TX3 TO DI-TX3.
           MOVE 0.5 TO ED.
           MOVE ED TO DI-TERM.
           MOVE 3 TO ED.
           MOVE ED TO DI-PI.
           DISPLAY DI-1.
           MOVE 0.5 TO PI.
           MOVE 0.5 TO TERM.
           MOVE 3 TO N.
       LOOP.
           MOVE N TO N2.
           SUBTRACT 2 FROM N2.
           MULTIPLY N2 BY N2.
           MULTIPLY N2 BY TERM.
           MOVE N TO N1.
           SUBTRACT 1 FROM N1.
           MULTIPLY N BY N1.
           MULTIPLY 4 BY N1.
           DIVIDE N1 INTO TERM.
           IF TERM < 0.0000000000001 THEN GO TO HALT.
           ADD TERM TO PI.
           MOVE PI TO W.
           MULTIPLY 6 BY W.
           MOVE W TO ED.
           MOVE ED TO DI-PI2.
           MOVE TERM TO ED.
           MOVE ED TO DI-TERM2.
           DISPLAY DI-2.
           ADD 2 TO N.
           IF N < 100 GO TO LOOP.
       HALT.
           STOP RUN.
