Points and Tips

When adding QUICKSTART to existing applications, using FD Interception can ease the conversion effort while minimizing changes to the code. You can use the QUICKSTART Conversion Facility to perform most of the manual conversion steps. See QUICKSTART-Conversion-Facility-QCF for more information.

When using FD Interception with Variable Length files, the COBOL/2 compiler option ADV=YES/NO affects which Copybooks to use. QSFDADV must be used if ADV=YES.

Use the COBOL RES compiler option whenever the main COBOL program CALLs other COBOL modules.

The VS/COBOL Statement: ON 1 statement should not be used as the variable used to evaluate this statement is internal to COBOL and its values are not restored upon restart. This causes the ON 1 to be true at each restart, rather than just upon the original run.

When using the INDEXED BY variable clause, and variable must retain its value across restarts, be sure to declare variable in one of the Checkpoint Areas. COBOL will automatically define variable if the programmer does not declare it. If COBOL defines it, it will be in a reserved area and QUICKSTART will not retain its value across restarts.

The use of the COBOL REWRITE verb is not supported. If records on a sequential file need to be “updated”, read the file for input, and write “updated” records to a new output file. This way, QUICKSTART can reposition both files if a restart is needed.

When using PERFORM ... VARYING variable FROM 1 BY 1 UNTIL ... and CKPT-RTN is being PERFORMED from within this loop, be sure to alter this structure to say:

PERFORM ... VARYING variable FROM variable+1 BY 1 UNTIL ...

with variable defined in the Checkpoint Area. This will allow restart to continue on in the series where it left off.

The use of the COBOL APPLY WRITE-ONLY statement has no effect on sequential output files managed by QUICKSTART.