IBM OS/390 User Manual

Page of 673
Notes:
 1. 
VSE: The address is that of a four-byte storage location containing the
required record identification in the same form as it is obtained from the
NOTE macro.
 2. MVS: The blockaddrcss is the address of a fullword on a fullword boundary
containing the required record identification in the same form as it is
obtained from the NOTE macro.
 3. The
MVS POINT macro is valid only for BSAM and BPAM.
 4. If you specify O P T C D = H in the data control block, the POINT macro
instruction can perform record positioning on VSE tapes that contain
embedded checkpoint records. Any embedded checkpoint records that are
encountered during the record positioning are bypassed and are not counted
as blocks spaced over. You must specify OPTCD=H in a JCL DD statement.
Do not use the POINT macro instruction to backspace VSE 7-track tapes that
are written in data convert mode and which contain embedded checkpoint
records.
POINTS Macro
The POINTS macro in VSE causes tapes to be rewound and positioned to the
first record following the label set. To achieve this in MVS, you must specify the
hexadecimal value 00000001 in the blockaddress field.
RELSE Macro
The function of the RELSE macro is the same under VSE and MVS. The MVS
RELSE macro is valid only for QSAM and QISAM.
TRUNC Macro
The function of the TRUNC macro is the same under VSE and MVS. The MVS
TRUNC macro is valid only for QSAM.
VSE
POINTS
filename
(1)
MVS
POINT
dcbaddress
,
blockaddress
(1-12)
(2-12)
(0)
VSE
RELSE
filename
(1)
MVS
RELSE
dcbaddress
(1-12)
VSE
TRUNC
filename
 (1) 
MVS
TRUNC
dcbaddress
(1-12)
300
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