COMTRAN (COMmercial TRANslator) is an early
programming language
A programming language is a system of notation for writing computer programs. Most programming languages are text-based formal languages, but they may also be graphical. They are a kind of computer language.
The description of a programming ...
developed at
IBM. It was intended as the business programming equivalent of the scientific programming language
FORTRAN (FORmula TRANslator). It served as one of the forerunners to the
COBOL language. Developed by
Bob Bemer
Robert William Bemer (February 8, 1920 – June 22, 2004) was a computer scientist best known for his work at IBM during the late 1950s and early 1960s.
Early life and education
Born in Sault Ste. Marie, Michigan, Bemer graduated from Cranb ...
, in 1957, the language was the first to feature the programming language element known as a
picture clause.
Contributions to COBOL
Several elements of COMTRAN were incorporated into COBOL:
*
Picture clause.
*Paragraphing: dividing code into paragraphs (with line breaks not significant).
*Paragraph names. Assigning names to paragraphs, and jumps ('s) are to a paragraph name, not to a line number.
* clause on file input operations.
*Figurative constant .
*Passing a numeric value () back to the operating system when the program
terminates.
Picture clause
A picture clause element defines how a particular data item should be formatted, for output. It consists of a string of letters and digits. It is similar to the FORTRAN format specifier seen in the READ and WRITE statements, or the formatting strings seen in more modern languages like C. This became an important part of COBOL.
Sample program
This is a sample COMTRAN program, doing payroll calculations.
[See the example on page 87 of th]
IBM F28-8043 Commercial Translator General Reference Manual, June 1960
(pdf, 8.2M)
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 'M' TO MASTER ERRORCODE, 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 WITHHOLDING.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.
References
Further reading
* ''IBM's Early Computers'', by Charles Bashe, Lyle Johnson, John Palmer, and Emerson Pugh, 1986, MIT Press, .
External links
Genealogy Programmers Solve Y2K in 1958IBM Commercial Translator General Reference Manual
(pdf, 8.2M) Page 87.
{{Programming languages
Procedural programming languages
Programming languages created in 1957