TPCBK Back to Index page
 
Prolog 
Control Block Contents 
   TPCBK DSECT
Storage Layout 
Cross Reference (Contains links to field and bit definitions)
Programming Interface Information:
This information is NOT intended to be
used as Programming Interfaces of z/VM.


  TPCBK Prolog Top of page
  
 NAME       : HCPTPCBK
 DESCRIPTION: TAPE PATHING CONTROL BLOCK
 DSECT      : TPCBK
 FUNCTION   : CONTAINS TAPE PATHING INFORMATION
 LOCATED BY : VDEVDYPT IN VIRTUAL DEVICE BLOCK
 CREATED BY : HCPVDSAT (DURING ATTACH OR DEDICATE PROC)
 DELETED BY : HCPDTDEV (DURING DETACH COMMAND PROCESSING)
 SERIALIZED : BEING ACCESSED FOR A UNIQUE TASK
 RELOCATION CONSIDERATIONS : This control block is relocated as part of a live
              guest relocation (LGR).  The bits and fields that
              need to be relocated are defined in the
              corresponding LGRTPCBK COPY file.  Whenever changes
              are made to this control block, consideration must
              be given to any effects these changes will have on
              a relocation.  If any new fields or bits are
              defined, they may need to be relocated.  If
              existing bits or fields are changed, corresponding
              modifications may be required in the LGR version of
              this control block.  Consider also the effects of
              these changes on a relocation involving a back-level
              release of CP.
 
 
  TPCBK Control Block Content Top of page
  




 TPCBK DSECT
Top of page


Hex   Dec Type/Val   Lng Label (dup)    Comments
---- ---- --------- ---- -------------- --------
0000    0 Structure      TPCBK          TAPE PATHING CONTROL BLOCK
0000    0 Bitstring   12 TPCBLOCK (8)   EIGHT ENTRIES OF PATHING
                                        INFORMATION
          0000000C       TPCSIZE        (*-TPCBK+7)/8 TPCBK SIZE IN
                                        DOUBLE WORDS
0000    0 Bitstring   12 TPCENTRY (0)   ONE ENTRY OF TAPE PATHING BLOCK
0000    0 Bitstring   11 TPCGROUP       TAPE PATH GROUP ID
000B   11 Bitstring    1 TPCFLAGS       TAPE PATHING FLAGS
          1... ....      TPCFGRP        X'80' TPCFGRP PATH IS GROUPED
          0000000C       TPCNXTEN       *-TPCENTRY
 
 
  TPCBK Storage Layout Top of page
  
          
*** TPCBK - TAPE PATHING CONTROL BLOCK
*
*     +-------------------------------------------------------+
*   0 |                                                       |
*     =                       TPCBLOCK                        =
*     |                                                       |
*     +-------------------------------------------------------+
*  60
*
*** TPCBK - TAPE PATHING CONTROL BLOCK
          
*** Overlay for TPCBLOCK in TPCBK
*
*     +-------------------------------------------------------+
*   0 |                       TPCGROUP                        |
*     |                    +------+---------------------------+
*   8 |                    |:FLAGS| C
*     +--------------------+------+
*
*** Overlay for TPCBLOCK in TPCBK
 
 
  TPCBK Cross Reference Top of page
  
 
Symbol         Dspl Value
-------------- ---- -----
TPCBLOCK       0000
TPCENTRY       0000
TPCFGRP        000B 80
TPCFLAGS       000B
TPCGROUP       0000
TPCNXTEN       000B 0000000C
TPCSIZE        0000 0000000C
 
This information is based on z/VM 7.2.0 Last updated on 24 Jun 2020 at 09:31:18 EDT.
Copyright IBM Corporation, 1990, 2020