Offset | Bytes in Length | Field Name | Description |
---|---|---|---|
16(10) | 1 | DCBKEYLE | Key length. |
17(11) | 1 | DCBDEVT | Device type. |
20(14) | 1 | DCBBUFNO | Number of buffers required for this data set: 0-255. |
21(15) | 3 | DCBBUFCA | Address of buffer pool control block. |
24(18) | 2 | DCBBUFL | Length of buffer: 0 - 32760 bytes. |
32(20) | 1 | DCBBFALN | Buffer alignment |
Code | |||
.... ..xx |
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.... ..10 |
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.... ..01 |
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.... ..11 |
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33(21) | 3 | DCBEODA | Address of a user-provided routine to handle end-of-data conditions. |
36(24) | 1 | DCBRECFM | Record format. |
Code | |||
10.. .... |
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01.. .... |
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11.. .... |
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..1. .... |
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...1 .... |
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.... 1... |
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.... .10. |
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.... .01. |
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.... .00. |
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.... ...1 |
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37(25) | 3 | DCBEXLSA | Exit list. Address of a user-provided list. |
42(2A) | 2 | DCBMACRF | Macro reference after OPEN: Contents and meaning are the same as those of the DCBMACR field before OPEN. |
50(32) | 2 | DCBMACR | Macro reference before OPEN: specifies the major macros and various options associated with them. Used by the open routine to determine access method. Used by the access method executors with other parameters to determine which load modules are required. |
Code | |||
50(32) | Byte 1 |
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00.0 0... |
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..1. .... |
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.... .1.. |
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.... ..1. |
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.... ...x |
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51(33) | Byte 2 |
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00.0 0000 |
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..1. .... |
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50(32) | Byte 1 |
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0.0. .0.. |
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.1.. .... |
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...1 .... |
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.... 1... |
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.... ..xx |
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51(33) | Byte 2 |
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1... .... |
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.1.. .... |
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..0. .... |
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...1 .... |
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.... 1... |
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.... .1.. |
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.... ..1. |
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.... ...1 |
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52(34) | 1 | DCBOPTCD | Option codes: |
Code | |||
1... .... |
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.1.. .... |
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..1. .... |
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...1 .... |
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.... 1... |
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.... ..1. |
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.... ...1 |
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.... .x.. |
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53(35) | 1 | DCBMAC | Extension of the DCBMACRF field for ISAM. |
Code | |||
xxxx ...x |
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.... 1... |
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.... .1.. |
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.... ..1. |
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54(36) | 1 | DCBNTM | Number of tracks that determines the development of a master index. Maximum permissible value: 99. |
55(37) | 1 | DCBCYLOF | The number of tracks to be reserved on each prime data cylinder for records that overflow from other tracks on that cylinder. To determine how to calculate the maximum number, see the section on allocating space for an indexed sequential data set in z/OS DFSMS Using Data Sets. |
56(38) | 4 | DCBSYNAD | Address of user's synchronous error routine to be entered when uncorrectable errors are detected in processing data records. |
60(3C) | 2 | DCBRKP | Relative position of the first byte of the key in each logical record. Maximum permissible value: logical record length minus key length. |
62(3E) | 2 | DCBBLKSI | Block size. |
64(40) | 4 | DCBMSWA | Address of the storage work area reserved for use by the control program when new records are being added to an existing data set. The DCBMSWA field contains significant information only when the data set is opened for BISAM. |
68(44) | 2 | DCBSMSI | Number of bytes in area reserved to hold the highest level index. The DCBSMSI field contains significant information only when the data set is opened for BISAM. |
70(46) | 2 | DCBSMSW | Number of bytes in work area used by control program when new records are being added to the data set. The DCBSMSW field contains significant information only when the data set is opened for BISAM. |
72(48) | 1 | DCBNCP | Number of copies of the READ-WRITE (type K) channel programs that are to be established for this data control block (99 maximum). |
73(49) | 3 | DCBMSHIA | Address of the storage area holding the highest level index. |
80(50) | 1 | DCBEXCD1 | First byte in which exceptional conditions detected in processing data records are reported to the user. |
1... .... | Lower key limit not found. | ||
.1.. .... | Invalid device address for lower limit (QISAM only). Record length check (BISAM only). | ||
..1. .... | Space not found. | ||
...1 .... | Invalid request. | ||
.... 1... | Uncorrectable input error. | ||
.... .1.. | Uncorrectable output error (BISAM only). Block could not be reached (BISAM only). | ||
.... ..1. | Block could not be reached (input) (QISAM only). Overflow record (BISAM only). | ||
.... ...1 | Block could not be reached (update) (QISAM only). Duplicate record (BISAM only). | ||
81(51) | 1 | DCBEXCD2 | Second byte in which exceptional conditions detected in processing data records are reported to the user (QISAM only). |
1... .... | Sequence check. | ||
.1.. .... | Duplicate record. | ||
..1. .... | DCB closed when error was detected. | ||
...1 .... | Overflow record. | ||
.... 1... | PUT: length field of record larger than length indicated in DCBLRECL. | ||
.... .xxx | Reserved bits. | ||
82(52) | 2 | DCBLRECL | Logical record length for fixed-length record formats. Variable-length record formats: maximum logical record length or an actual logical record length changed dynamically by the user when creating the data set. |
150(96) | 2 | DCBNCRHI | Number of storage locations needed to hold the highest level index. |
197(C5) | 1 | DCBOVDEV | Device type for independent overflow. |