The format of the MSGDISP macro with the VERIFY parameter is:

>>-+-------+--MSGDISP--VERIFY--,UCB=-(reg)--+---------+--------->
   '-label-'                                '-,LABEL=-'   

   .-'S'--.                                                  
>--+-'A'--+--+-------------------+--+--------------------+------>
   +-'N'--+  '-,MF=-+-L--------+-'  '-,SER=-+-'volser'-+-'   
   +-'X'--+         '-(E,addr)-'            '-addr-----'     
   '-addr-'                                                  

>--+----------------+--+----------------+----------------------><
   |        .-NO--. |  |        .-YES-. |   
   '-,TEST=-+-YES-+-'  '-,WAIT=-+-NO--+-'   

VERIFY

Displays the serial number and label type of a volume that has been accepted for processing. The serial number is displayed on the pod in positions 2 through 7, and the 1 character label type in position 8. Position 1 remains blank. The display lasts until the next display request is executed.

UCB=(reg)—(2-12)

Specifies a register containing the UCB address for the device. Use the address of a UCB, not a UCB copy.

LABEL='A' or 'N' or 'S' or 'X' or addr

Specifies label type of the mounted volume in position 8 of the display. If an unknown label type other than a blank is specified, a "?" is displayed.

'A'

Specifies ISO/ANSI (AL) or ISO/ANSI with user (AUL) labels. Apostrophes are required.

'N'

Specifies no labels (NL), LTM (VSE), or bypass label processing (BLP). Apostrophes are required.

'S'

Specifies IBM® Standard (SL) or IBM Standard with user (SUL) labels. Apostrophes are required.

'X'

Specifies nonstandard (NSL) labels. Apostrophes are required.

addr—RX-type address, A-type address, or (2-12)

Specifies the address of an area containing an “A”, “N”, “S”, or “X” (see explanations below for these characters). For MF=L, you can only specify an A-type address.

MF=L or (E,addr)

Specifies either the execute or list form of MSGDISP. If you do not specify this parameter, the standard form of the macro is used.

L

Specifies the list form of MSGDISP. This generates a parameter list that can be used as input to the execute form. The execute form can modify the parameter list.

(E,addr)

Specifies that the execute form of the macro and an existing parameter list is to be used.

addr—RX-type address, (1), or (2-12)

Specifies the address of the parameter list.

SER='volser' or addr

Specifies the serial number of the volume that has been verified. The serial number displays in positions 2 through 7. If you do not specify SER, the system supplies the volume serial number. If the serial number is not available, a scratch volume is used, unless the volume use attribute indicates a default of “PRIVAT”.

'volser'

Specifies the volume serial number as a literal. Express® in apostrophes.

addr—RX-type address, A-type address, or (2-12)

Specifies the address of the volume serial number. For MF=L, you can only specify an A-type address.

TEST=NO or YES

Specifies whether the macro expansion is to include code that will test the UCB to determine whether message display is supported. If the result of the test is that the message display is not supported, an SVC is not invoked.

NO

Specifies that the macro expansion is not to include code that tests the UCB to determine whether the device supports message display.

YES

Specifies testing the UCB by the MSGDISP macro before attempting to invoke the message display service routine.

Requirement: TEST=YES requires you to include the UCB mapping macro (IEFUCBOB) in the source code. If this provision is not followed, a program check in expansion code might result. Programs running in AMODE 24 and invoking the MSGDISP macro with the TEST=YES parameter cannot pass the actual address of a UCB that resides above the 16 MB line. These programs must pass the captured UCB address or, if an actual address is passed, the UCB must reside below the 16 MB line.

WAIT=NO or YES

Specifies when control is to be returned to you and that the MSGDISP function is not to wait for completion of I/O initiated on the caller's behalf. When MSGDISP returns, the I/O request might still be running.

NO

Specifies that the MSGDISP function is not to wait for completion of I/O that is initiated on the caller's behalf. When MSGDISP returns, the I/O request might still be running. I/O return codes are not returned, and I/O errors are recorded in the same manner as any permanent error by the error recovery procedure.

YES

Specifies that control is to be returned after I/O is complete.