SabreTalk

SabreTalk is a discontinued dialect of PL/I for the S/360 IBM mainframes running the TPF platform. SabreTalk was developed jointly by American Airlines, Eastern Air Lines and IBM. SabreTalk is known as PL/TPF (Programming Language for TPF).^[1]

SabreTalk programs still run in the British Airways Flight Operations system (FICO) under ALCS, using a commercially available automatic converter to translate SabreTalk programs to C programs. Both the Reservations and Operations Support System (OSS) of Delta Air Lines were developed using both SabreTalk and IBM 360 Assembler. Although development is currently restricted to C++, the majority of Delta's programming platform remained in Sabretalk until recently in the 2010s.

Because of the availability of translators^[2]^[3] from SabreTalk to C and because it is no longer supported by the original developers, several companies are beginning the move away from SabreTalk to purely C-based programs.

Code Sample:

 SAMPLE: PROCEDURE;
       DECLARE ARRAY(10) DECIMAL(5) BASED(POINTUR);
       DECLARE COUNTER BINARY(15) ALIGNED;
       DECLARE TOTAL BINARY(31) ALIGNED;
       START(POINTUR=#RG1);                  /* RECEIVE POINTER TO ARRAY IN REGISTER 1 */
       TOTAL = 0;
 LOOP: 
       DO COUNTER = 0 TO 10 BY 2;
         TOTAL = TOTAL + ARRAY(COUNTER);     /* TALLY EVEN NUMBERED ITEMS */
       END LOOP;
       IF TOTAL = 0 THEN                     /* VALUE OF TOTAL COMPUTED? */ 
          ENTRC ERRO;                        /* N=CHECK VALIDITY IN PROG ERRO W/RETURN EXPECTED*/
       BACKC(#RAC= TOTAL);                   /* BACK TO CALLING PROGRAM PASSING VALUE OF       */
 END SAMPLE;                                 /*  TOTAL IN REGISTER RAC.                        */

References

^ S. J. Hobson, "ALCS -- A High-Performance High-Availability DB/DC Monitor", p. 136 (footnote 2) in High Performance Transaction Systems, 2nd International Workshop, Asilomar Conference Center, Pacific Grove, California, USA, September 28-30, 1987, Proceedings. Lecture Notes in Computer Science 359, Springer 1989, ISBN 3-540-51085-0.
^ S. Dhinakar Jacob, Madhuchhanda Das, "TALK2C: A Tool for Automatic Migration," icpc, pp.288, 11th IEEE International Workshop on Program Comprehension (IWPC'03), 2003
^ Ira Baxter, "Approaches for Code Modernization", TPF Users Group meeting 2019

External links

Sabretalk Programmer's Reference Guide at the Wayback Machine (archived October 21, 2012)
Robinson, Jeff (March 2001). "Moving From SabreTalk to "C" Part 1: How SabreTalk "Procedures" Become "C" Functions" (PDF). ACP/TPF Today. Archived from the original (PDF) on March 26, 2012.

[1] S. J. Hobson, "ALCS -- A High-Performance High-Availability DB/DC Monitor", p. 136 (footnote 2) in High Performance Transaction Systems, 2nd International Workshop, Asilomar Conference Center, Pacific Grove, California, USA, September 28-30, 1987, Proceedings. Lecture Notes in Computer Science 359, Springer 1989, ISBN 3-540-51085-0.

[2] S. Dhinakar Jacob, Madhuchhanda Das, "TALK2C: A Tool for Automatic Migration," icpc, pp.288, 11th IEEE International Workshop on Program Comprehension (IWPC'03), 2003

[3] Ira Baxter, "Approaches for Code Modernization", TPF Users Group meeting 2019

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