Defining data set types and changing the default attributes

If the pre-defined data set types TSO/E provides are not suitable for your installation, you can define your own data set types with specific attributes. You can also change the default attributes of the data set types TSO/E provides for your processing requirements. If you define a data set type, you can change the attributes you specified.

To define data set types or change the attributes, use the IKJEDIT macro instruction and submit a System Modification Program Extended (SMP/E) job to perform the definition or updates. Using IKJEDIT, specify the name of the data set type you are defining or changing and the specific attributes for the data set type. For information about the syntax of IKJEDIT, see IKJEDIT macro.

IKJEDIT generates the following two CSECTs:

IKJEBEPD, which is link-edited with the IKJEBEPS module in SYS1.CMDLIB
IKJEBINS, which is link-edited with the EDIT command in SYS1.CMDLIB.

Both CSECTs are required.

TSO/E provides a sample job in SYS1.SAMPLIB member IKJTSMPE that shows how to use IKJEDIT.Instructions for using the sample job are included in the SYS1.SAMPLIB member.

If you change the attributes of a data set type, any attributes that you do not explicitly specify on IKJEDIT are not changed. If you define a new data set type and do not explicitly specify a particular attribute, you get the following default values:

Block size:: 3120
Record format:: Fixed
Default LRECL:: Fixed - 80, Variable - 255
Maximum LRECL:: Fixed - 255, Variable - 255
Data conversion:: CAPS

TSO/E does not provide defaults for the following attributes:

Checker name
Prompter name
Prompter input

If you used the EDIT SYSGEN macro to change the default attributes of TSO/E-supplied data set types, the defaults TSO/E provides overlay your changes. After system generation, use IKJEDIT to change the default attributes. By using IKJEDIT, future SYSGENs or IOGENs do not replace your values.