BAM macro instructions

The choice of which non-VSAM macro to use depends on which access method is appropriate for the type of data set being processed:

Basic and queued sequential access method (BSAM and QSAM) macros are used to process sequential data sets on DASD, members of partitioned data sets or PDSEs, z/OS UNIX files, magnetic tape files, subsystem data sets, TSO terminals and unit record devices.
Basic partitioned access method (BPAM) macros are used to process partitioned data sets and PDSEs.
Basic direct access method (BDAM) macros are used to process direct data sets.
Basic and queued indexed sequential access method (BISAM and QISAM) macros were designed to process indexed sequential data sets, which are no longer supported. All indexed sequential data sets should have been converted to key sequenced data sets (KSDS) prior to your migration to z/OS V1R7. However, BISAM and QISAM macro descriptions in this topic were written as if you were accessing real ISAM data sets, and some parts of this topic describe functions that are no longer supported.
The ISAM interface for VSAM, described in z/OS DFSMS Using Data Sets, helps in converting programs from ISAM to VSAM, and the description of that interface may help you understand this topic. To use real indexed sequential data sets, see documentation for z/OS releases prior to z/OS V1R7.

All macros described in this book are in the main system macro library, SYS1.MACLIB.

You can use certain access method services commands, such as ALLOCATE, ALTER, DEFINE NONVSAM, DELETE, LISTCAT, PRINT, and REPRO, with non-VSAM data sets.

All non-VSAM macros may be issued in 24-bit addressing mode. Many non-VSAM macros can also be issued in 31-bit addressing mode. When you issue a macro in 24-bit mode, data referred to by the macro must reside below the 16MB line. When you issue a macro in 31-bit mode, all addresses in registers and four-byte fields must contain valid 31-bit values although they may point below the 16MB line. The macro description will state whether it can be issued in 31-bit addressing mode and whether any input fields may reside above the 16MB line.

IBM recommends that if your program supports execution in 64-bit, then you should precede the first macro call with a call to the SYSSTATE macro with AMODE64=YES. Since none of the macros described in this document support invocation in 64-bit, AMODE64=YES should not be in effect when calling the macros described in this book.

You can define or allocate data sets using dynamic allocation, which is SVC 99. BSAM, BPAM and QSAM support the NOCAPTURE, XTIOT, and DSAB above the line options of dynamic allocation. Using these three options of dynamic allocation reduces the overhead of dynamic allocation and reduces virtual storage usage below the 16 MB line. Dynamic allocation is described in z/OS MVS Programming: Authorized Assembler Services Guide.

The non-VSAM macros can generate reenterable code, depending on the form in which parameters are expressed.

You can store executable programs in PDSE libraries. Although structurally identical, PDSE libraries are of two types:

A data library, containing source programs, user data, and other record-oriented information.
A program library, containing executable programs referred to as program objects.

The type of library is determined, not at allocation time, but when the first member is stored in it. For additional information on program objects and libraries, see z/OS MVS Program Management: User's Guide and Reference and z/OS MVS Program Management: Advanced Facilities.