Programming Interface Information: This information is NOT intended to be
used as Programming Interfaces of VM/ESA. It is to be used for diagnosis only.

DPSBK

Prolog  

Control Block Contents  

DPSBK DSECT

Storage Layout  

Cross Reference (Contains links to field and bit definitions)  

DPSBK Prolog

 NAME       : HCPDPSBK
 DESCRIPTION: Dasd Programming Services Block
 DSECT      : DPSBK
 FUNCTION   : This DSECT maps each entry in the device table
              located in module HCPBST.
 LOCATED BY : HCPBSTBL in module HCPDPS is device table origin
 CREATED BY : Device table is predefined, not allocated at
              run time
 DELETED BY : Never deleted
 SERIALIZED : The device table is read only, never update

 

DPSBK Control Block Content


DPSBK DSECT

Hex Dec Type/Val Lng Label (dup) Comments ---- ---- --------- ---- -------------- -------- 0000 0 Structure DPSBK Dasd Programming Services Block 0000 0 Bitstring 1 DPSBLKSZ Supported blocksize 0001 1 Bitstring 1 DPSINDEX 3 bit representation These are the values for each element in the 3-bit maps that indicate by cylinder whether it is std, non-std, or non-cachable. Also: adding 7 to the value in this field ('std cyl size x' only) results in a shift value to calculate the number of records of size 'x' in a given amount of storage. E.G. DPSINDEX = DPSI1K = 3 => 3+7=10 => 2**10=1K. Shift number of bytes right 10 bits gives number of 1K-byte records in that storage. (4 per 4K page). 3 bit representation of sizes: 00000001 DPSI256 1 3 bits for std cyl size 256 00000002 DPSI512 2 3 bits for std cyl size 512 00000003 DPSI1K 3 3 bits for std cyl size 1K 00000004 DPSI2K 4 3 bits for std cyl size 2K 00000005 DPSI4K 5 3 bits for std cyl size 4K 00000006 DPSINS 6 3 bits for non-standard cyl 00000007 DPSINC 7 3 bits for non-cachable cyl 0002 2 Signed 2 DPSRECPC Records per cylinder for this blocksize 0004 4 Signed 2 DPSTKPC Tracks per cylinder 0006 6 Signed 2 DPSRCPTK Records per track for this blocksize 0008 8 Signed 2 DPSPGPT Pages needed to hold track 000A 10 Bitstring 1 DPSFLAG Device dependencies 1... .... DPSRMCKD X'80' Supports read multiple count key data CCWs .1.. .... DPSOVFL X'40' Minidisk formatted with overflow records ..1. .... DPSFBA X'20' FBA device .... .... DPSNODEP X'00' No dependencies 000B 11 Bitstring 1 DPSPTEIX Index to PTE set for this sz 000C 12 Bitstring 4 DPSSECTR Address of sector values for records of this blocksize 0010 16 Bitstring 1 DPSNEXT (0) Next entry in device table 00000004 DPSSHIFT 4 Size of the DPSBK as a shift value (power of 2). 2**4=16=DPSSIZEB

 

DPSBK Storage Layout

*** DPSBK - Dasd Programming Services Block
*
*     +------+------+-------------+-------------+-------------+
*   0 |:BLKSZ|:INDEX|  DPSRECPC   |  DPSTKPC    |  DPSRCPTK   |
*     +------+------+------+------+-------------+-------------+
*   8 |  DPSPGPT    |:FLAG |:PTEIX|         DPSSECTR          |
*     +-------------+------+------+---------------------------+
*  10 |                                                       |
*     =                       DPSNEXT                         =
*     |                                                       |
*     +-------------------------------------------------------+
*
*** DPSBK - Dasd Programming Services Block

 

DPSBK Cross Reference

(contains links to field and bit definitions)
Symbol         Dspl Value
-------------- ---- -----

DPSBLKSZ 0000

DPSFBA 000A 20

DPSFLAG 000A

DPSINC 0001 00000007

DPSINDEX 0001

DPSINS 0001 00000006

DPSI1K 0001 00000003

DPSI2K 0001 00000004

DPSI256 0001 00000001

DPSI4K 0001 00000005

DPSI512 0001 00000002

DPSNEXT 0010

DPSNODEP 000A 00

DPSOVFL 000A 40

DPSPGPT 0008

DPSPTEIX 000B

DPSRCPTK 0006

DPSRECPC 0002

DPSRMCKD 000A 80

DPSSECTR 000C

DPSSHIFT 0010 00000004

DPSTKPC 0004


This information is based on VM/ESA 2.4.0.
Last updated on 3 Aug 1999 at 11:52:29 EDT.
Copyright IBM Corporation, 1990, 1999