EXEC Statement

Every JCL file must contain at least one and up to 255 valid EXEC statements. Since this release of the Tachyon Operating System does not support JCL procedures, each EXEC statement must include the PGM parameter. Each EXEC statement begins the definition of a job step.

The j390 program accepts most of the EXEC statement parameters supported by z/OS. These include the step name and the ACCT, ADDRSPC, CCSID, COND, DYNAMBR, MEMLIMIT, PARM, PGM, PERFORM, RD, REGION and TIME key word parameters. Most of the EXEC statement parameters are only checked for syntax and have no meaning to the Tachyon Operating System. The following EXEC statement parameters are significant:

Step Name

The step name is used to generate temporary data set names and it is stored in various control blocks.

DYNAMBR

The DYNAMBR parameter specifies the number of TIOT entries to be reserved for dynamic allocation. This release of the Tachyon Operating System does not support dynamic allocation but it does honor the DYNAMBR parameter and will reserve the specified number of TIOT entries.

COND

The COND parameter specifies the conditions which will cause the job step to be executed or bypassed.

PARM

The PARM parameter specifies a string that will be passed to the program.

PGM

The PGM parameter specifies the name of the program to be executed by the Tachyon Instruction Emulator. This release of the Tachyon Operating System does not support the *.ddname form of the PGM parameter.

PGM=IEFBR14 is recognized by the Tachyon Operating System as a special case. For this program, the step always ends with a condition code of zero without invoking the Tachyon Instruction Emulator.

Programs referenced by the PGM parameter and any programs loaded using the LINK(X), LOAD and XCTL(X) services must exist as files somewhere that the Tachyon Operating System can find them. Like z/OS, the Tachyon Operating System normally searches for programs in the JOBLIB or STEPLIB first, then the Link Pack Area (LPA) and finally in the LNKLST concatenation. The LPA and the LNKLST are defined using the LPALSTxx.ini and the LNKLSTxx.ini configuration files. Any data sets referenced in the LPALSTxx.ini or LNKLSTxx.ini files or in JOBLIB or STEPLIB DD statements must be defined in DSNMAPxx.ini DSNMAP configuration file statements using FILEDATA(BINDER).

Example EXEC statement

//MYSTEP EXEC PGM=MYPROG