//SYSPRINT DD SYSOUT=class //SYSUT1 DD ... //SYSUT2 DD ... //SYSIN DD ... Scheduler utilities IEFBR14 IEFBR14 is a dummy program, normally inserted in JCL when the only desired action is allocation or deletion of datasets. An example of an IEFBR14 step: //IEFBR14 JOB ACCT,'DELETE DATASET' //STEP01 EXEC PGM=IEFBR14 //DELDD DD DSN=xxxxx.yyyyy.zzzzz, // DISP=(MOD,DELETE,DELETE),UNIT=DASD The calling sequence for OS/360 contained the return address in Register 14. A branch to Register 14 would thus immediately exit the program. However, before and after executing this program, the operating system would allocate & deallocate datasets as specified in the DD statements, so it is commonly used as a quick way to set up or remove datasets. It consisted initially as a single instruction a "Branch to Register" 14. The mnemonic used in the IBM Assembler was BR and hence the name: IEF BR 14. IEF is the "prefix" of OS/360's "job management" subsystem. This single instruction program had an error in it — it didn't set the return code. Hence a second instruction had to be added to clear the return code so that it would exit with the correct status. There was an additional error reported and fixed by IBM on this now two instruction program. This error was due to the IEFBR14 program not being link-edited as reenterable (simultaneously usable by more than one caller). Some hackers have taken IEFBR14 and changed the BR 14 instruction to BR 15, thereby creating "the shortest loop in the world", as register 15 contains the address of the IEFBR14 module itself, and a BR 15 instruction would simply re-invoke the module, forever. System utilities These utilities are normally used by systems programmers in maintaining the operation of the system, rather than by programmers in doing application work on the system. ICKDSF ICKDSF ("Device Support Facility") installs, initializes and maintains DASD, either under an operating system, or standalone. IEHATLAS Assign alternate tracks to defective tracks. IEHDASDR IEHDASDR can performs several operations for direct access storage devices (DASD) Initialize a DASD volume, with optional surface checking Assign alternate tracks to defective tracks Print tracks on a DASD Create a backup of a DASD volume on tape Restore DASD volumes from backup tapes. IBM eventually stopped adding support for new device types to IEHDASDR and directed customers to the free DSF for initializing volumes and to the chargeable DASDR (5740-UT1) and Data Facility/Data Set Services (5740-UT3, DF/DSS) for