gtpi1m55System Installation Support Reference

Tape Library Validation

The tape library validation user exit, CORU, can be activated by any function to validate a tape volume or change the category of a tape volume.

There are 2 branch vectors for CORU (CT7UOUT and CT7UCHNG). The branch vectors are defined in the TAPEQ macro. The branch vectors must be loaded into R1 before entering CORU. If the value passed in R1 is not valid, an OPR-771 system dump is issued and the ECB is exited.

CORU and its branch vectors do the following user-defined functions:

Perform volume serial number validation
Branch vector CT7UOUT checks a tape volume to make sure it can be used as an output tape. CORU is shipped with code that issues a message if the internal volume serial number and the external volume serial number do not match. If the volsers do not match for a ZTINT request, the operation is ended. If the internal volume serial number is not present, it becomes the same as the external volume serial number. You can add your own code to accept or reject certain categories.

Change tape category
Branch vector CT7UCHNG returns a new library category for a tape volume. CORU is shipped with code that changes the category of a tape to a TPF predefined category default from the TSTB2 field, CPMTDCAT. You can change the predefined defaults or add your own.

Input

Programming Considerations

Return Values

From branch vector CT7UOUT, R1 should contain one of the following:

0
Volume valid for output.

4
Volume mismatch; user defined as not allowed for output.

8
Volume not valid for output.

C
Volume mismatch; user defined as allowed for output.

From branch vector CT7UCHNG, R1 should contain a hexadecimal category value of 0000-FFFF.