IGXMSGEX  CSECT
IGXMSGEX  AMODE 31
IGXMSGEX  RMODE ANY
          STM    14,12,12(13)       save callers registers
          LR     12,15              establish base register
          USING  IGXMSGEX,12
*   NOTE: This module must be RE-ENTRANT!!! This example does not
*   obtain a save area, but if one is necessary, it would need to
*   be GETMAINed.
*
*   To test for a specific job name or step name the following
*   code sequence may be used
*   NOTE: This code assumes that a deferred tape mount is done
*   if deferred tape mounts are not requested, the TIOCNJOB
*   field will contain 'INIT    ' and the TIOCSTEP+8 field
*   will contain the 8 byte job name
          USING  PSA,0
          L      15,PSATOLD         get TCB address
          USING  TCB,15             map TCB
          L      15,TCBTIO          get TIOT address
          USING  TIOT,15            map TIOT
          LTR    15,15              is there a TIOT
          BZ     NOTIOT             no, branch
          CLC    TIOCNJOB,MYJOB     check for interesting job
          BNE    NOTMYJOB           branch if "not my job"
          CLC    TIOCSTEP(8),MYSTEP  check for interesting step
          BNE    NOTMYSTP           branch if "not my step"
          DROP   15
*   Of the bits in the control byte, only the ACL request bit
*   may be modified. If any other bit is changed, IGX00030 will
*   reset it to the original state. If the ACL request bit is
*   set on, it will only be honored if the device actually
*   supports the automatic cartridge load (ACL) feature. The UCB
*   can be tested to ensure that the ACL feature is supported.
*   The system will have set ACL request bit on if the device
*   supports ACL, the ACL load is ready, and the volser is SCRTCH or
*   PRIVAT.
          USING  PLIST,1            map input parameters
          L      2,MSGTEXTA         get message text address
          USING  MSGTEXT,2          map message text
          TM     CONTROL,ACL        is ACL request bit on
          BO     ACLON              yes branch
          L      3,UCBA             get UCB address from PLIST
          USING  UCB,3

*   We could just always set the bit on and let the calling module
*   (IGX00030) test to see if the ACL is supported, but we will test
*   the UCB just as an example.
          TM     UCBTFL1,UCBCSL     is ACL supported
          BNO    ACLOFF             no, branch
          OI     CONTROL,SETACLON   set ACL request bit on
SETACLON  EQU    X'01'              ACL on bit
ACLON     EQU    *                  ACL on
ACLOFF    EQU    *                  ACL off
*
NOTMYJOB  EQU  *
NOTMYSTP  EQU  *
NOTIOT    EQU  *
*   NOTE: This exit could also be used to update the message text
*   in the parameter list (i.e. MSG1 and MSG2 fields). An example
*   of this has not been included because the update would be
*   specific to implementation details of a specific installation.
          LM     14,12,12(13)       restore callers registers
          SR     15,15              set return code, (not used by
*                                    IGX00030, just good practice)
          BR     14                 return to caller
MYJOB     DC     CL8'MYJOB'         job name of interest
MYSTEP    DC     CL8'MYSTEP'        step name of interest
*  Parameter list pointed to be register 1
PLIST     DSECT
UCBA      DS     A                  UCB address
MSGTEXTA  DS     A                  Message text address
MSGTEXT   DSECT
CONTROL   DS     CL1
ACL       EQU    X'01'              ACL request bit
MSG1      DS     CL8                first message
MSG2      DS     CL8                second message
****** Include control block mapping macros
          IHAPSA                    PSA mapping
          IKJTCB                    TCB mapping
TIOT      DSECT                     provide DSECT statement for TIOT
          IEFTIOT1                  TIOT mapping
UCB       DSECT                     provide DSECT statement for UCB
          IEFUCBOB                  UCB mapping
          END