Allocating the internal reader data set

You can allocate an internal reader data set, in any address space, either with JCL or dynamically, as follows:

Define the data set in the JCL for a job:
```
//JOBJCL DD SYSOUT=(A,INTRDR)
```
Note:
1. “INTRDR” is an IBM-reserved name identifying the internal reader as the program to process this data set after it is created and written to.
2. The SYSOUT class on this DD statement becomes the message class for the submitted job unless you specify MSGCLASS on the JOB statement.
Use the following dynamic allocation text unit keys to dynamically allocate an internal reader data set:
- DALSYSOU — define the SYSOUT data set and its class.
- DALSPGNM — specify the SYSOUT program name (INTRDR).
- DALCLOSE — request that INTRDR be deallocated at close.
- DALRTDDN — request the return of the ddname assigned by dynamic allocation.
- DALLRECL — specify the record length of any instream data set.
- DALRECFM — specify the record format of any instream data set.
Note: DALCLOSE, DALRTDDN, DALLRECL and DALRECFM are optional dynamic allocation text unit keys.

For the format details of dynamic allocation text unit keys, see z/OS MVS Programming: Authorized Assembler Services Guide.

Note:

An INTRDR data set can contain any number of jobs.
The output destination of the INTRDR data set becomes the default print/punch routing of all jobs contained within it.
INTRDR data sets contain sequential, fixed-length, or variable-length records. Instream data records can be up to 254 bytes long. Note, however, that JCL images in the data sets must be exactly 80 bytes long.