gtpi1m2mSystem Installation Support Reference

Validate Tape for Output

User exit routine UCCVTO validates that a tape can be used for output before it is automatically used by automount routines as an ALT tape. UCCVTO is invoked from the exit point VTO, which is nondynamic, in one of the following routines:

General Conditions at Entry

The registers at entry to UCCVTO are:

R0
R0 must have one of the following values:

X'00'
Equated to VTOCEDT, indicates the exit was called during system error processing and came from segment CEDT.
Note:
This should be taken into consideration when adding code to the exit.

X'04'
Equated to VTOCEFA, indicates the exit came from segment CEFA.

R1
Pointer to the IBM standard VOL1 label (addressable by the equates in TAPEQ).

R11-R15
See User Exit Routines - Common Entry Conditions.

System Conditions at Entry

System state
Supervisor

System mask
Masked

Protect key
0

Address space
SVM.

Programming Considerations at Entry

  1. See User Exit Routines - Common Entry Conditions.
  2. See User Exit Routines - Common Programming Considerations for other considerations.

Programming Considerations on Return

See User Exit Routines - Common Return Conditions.

General Conditions on Return

  1. If the user exit returns condition code zero, the process of mounting the tape as an ALT tape continues.
  2. If the exit returns a nonzero condition code, the tape is not mounted as an ALT tape and a message informs the operator that the tape is not valid for output. If the user exit is activated from CEFA, the COSK0288E message is sent. If the user exit is activated from CEDT, the CPSE0027E message is sent.
  3. See User Exit Routines - Common Return Conditions.