Use &SYSADATA_DSN in a macro definition to obtain the name of the data set to which the assembler is writing the associated data.

The local-scope system variable symbol &SYSADATA_DSN is assigned a read-only value each time a macro definition is called.

z/OS

When the assembler runs on the z/OS operating systems, the value of the character string assigned to &SYSADATA_DSN is always the value stored in the JFCB for SYSADATA. If SYSADATA is allocated to DUMMY, or a NULLFILE, the value in &SYSADATA_DSN is NULLFILE.

For example, &SYSADATA_DSN might be assigned a value such as:

IBMAPC.SYSADATA

z/VM

When the assembler runs on the CMS component of the z/VM operating systems, the value of the character string assigned to &SYSADATA_DSN is determined as follows:

Table 1. Contents of &SYSADATA_DSN on CMS

SYSADATA Allocated To:	Contents of &SYSADATA_DSN:
CMS file	The 8-character file name, the 8-character file type, and the 2-character file mode of the file, each separated by a space
Dummy file (no physical I/O)	DUMMY
Labeled tape file	The data set name of the tape file
Unlabeled tape file	TAPn, where n is a value from 0 to 9, or A to F.

For example, &SYSADATA_DSN might be assigned a value such as:

SAMPLE   SYSADATA A1

^z/VSE

The value of the character string assigned to &SYSADATA_DSN is the file ID from the SYSADAT dlbl.

For example, &SYSADATA_DSN might be assigned a value such as:

MYDATA