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'COMTRAN' (COMmercial TRANslator) is an early programming language developed at IBM. It was intended as the business programing equivalent of the scientific programming language FORTRAN (FORmula TRANslator). It served as one of the forerunners to the COBOL language. Developed by Bob Bemer, in 1957, the language featured the first programming language element known as the Picture Clause.

Contents

Contributions to COBOL

Picture Clause

Sample Program

References

Contributions to COBOL

Several elements of COMTRAN were incorporated into COBOL:

★ Picture Clause. (See below.)

★ Paragraphing: dividing code into paragraphs (with line breaks not significant).

★ Paragraph names. Assigning names to paragraphs, and jumps (GO TO's) are to a paragraph name, not to a line number.

★ AT END clause on file input operations.

★ Figurative constant HIGH-VALUE.

★ passing a numeric value back when the program ends (RETURN-CODE).

Picture Clause

''Main article: Picture Clause''
The Picture Clause element defines the length of any given datum, much like a dictionary defines words. In particular the Picture Clause determines whether the datum contains letters and numbers, and other characteristics of the data, including format, size, and type.

Sample Program

This is a sample COMTRAN program, doing payroll calculations.

01001 
★ PROCEDURE

01002 CALL (EMPLOYEE.NUMBER)  EMPLOYNO,

01003      (BONDEDUCTION)     BONDEDUCT,

01004      (BONDENOMINATION)  BONDENOM,

01005      (BONDACCUMULATION) BONDACCUM,

01006      (INSURANCE.PREM)   INSPREM,

01007      (RETIREMENT.PREM)  RETPREM,

01008      (DEPARTMENT.TOTAl) DPT.

01009 START. OPEN ALL FILES.

01010 GET.MASTER. GET MASTER, AT END DO END.OF.MASTERS.

01011 GET.DETAIL. GET DETAIL. AT END GO TO END.OF.DETAILS.

01012 COMPARE.EMPLOYEE.NUMBERS. GO TO COMPUTE.PAY WHEN DETAIL EMPLOYNO

01013       IS EQUAL TO MASTER EMPLOYNO, LOW.DETAIL WHEN DETAIL

01014       EMPLOYNO IS LESS THAN MASTER EMPLOYNO.

01015 HIGH.DETAIL. MOVE IMI TO MASTER ERRORCODET FILE MASTER IN

01016       ERROR.FILE.

01017         GET MASTER, AT END DO END.OF.MAsTERS.

01018         GO TO COMPARE.EMPLOYEE.NUMBERS.

02001 LOW.DETAIL. MOVE 'D' TO DETAIL ERRORCODE, FILE DETAIL IN

02002        ERROR.FILE.

02003          GO TO GET.DETAIL.

02004 END.OF.MASTERS. IF DETAIL EMPLOYNO = HIGH.VALUE THEN GO TO

02005         END.OF.RUN OTHERWISE SET MASTER EMPLOYNO = HIGH.VALUE.

02006 END.OF.DETAILS. IF MASTEREMPLOYNO = HIGH.VALUE THEN GO TO

02007         END.OF.RUN OTHERWISE SET DETAIL EMPLOYNO = HIGH.VALUE, GO

02008         TO COMPARE.EMPLOYEE.NUMBERS.

02009 END.OF.RUN. MOVE CORRESPONDING GRAND.TOTAL TO PAYRECORD, FILE

02010        PAYRECORD, CLOSE ALL FILES.

02011          STOP 1234.

02012 COMPUTE.PAY. IF DETAIL HOURS IS GREATER THAN 40 THEN SET DETAIL

02013        GROSS = (DETAIL HOURS - 40) 
★  MASTER RATE 
★  1.5.

02014        SET DETAIL GROSS = DETAIL GROSS + MASTER RATE 
★  40, DO

02015      FICA.ROUTINE, DO WITHOLDING.TAX.ROUTINE.

02016        IF MASTER BONDEDUCT IS NOT EQUAL TO ZERO THEN DO

02017      BOND.ROUTINE.

02018        DO SEARCH FOR INDEX = 1(1)12.

02019 NET. SET PAYRECORD NETPAY = DETAIL GROSS - DETAIL FICA - DETAIL

02020        WHT -DETAIL RETIREMENT - DETAIL INSURANCE - DETAIL

02021        BONDEDUCT.

(From IBM F28-8043 Commercial Translator General Reference Manual.) ^[1]

References

★ Genealogy Programmers Solve Y2K in 1958

★ IBM Commercial Translator General Reference Manual (pdf, 8.2M)