On Wed, 8 Aug 2012 09:18:35 -0400, Shmuel Metz (Seymour J.)
<[email protected]> wrote:
>
>>To increment the record number by one, add 256 to the "TTR".
>
>ITYM add 256 to the TTRz.
>
Does this work when you cross a track boundary? I might expect it to
work less well for TTRz than for relative block number.
And, in Using Data Sets:
http://publibz.boulder.ibm.com/cgi-bin/bookmgr_OS390/BOOKS/dgt2d490/3.8.7.8
3.8.7.8 Using the POINT Macro to Position to a Block
... If the current record spans blocks, setting the z byte of the TTRz
field to one lets
you access the next record (not the next segment).
Does this mean that if the current record spans several blocks, setting the
z byte causes enough intervening blocks containing enough segments to be
skipped that the block read contains the first segment of the next record?
Wow!
Does this apply to RECFM=VBS only? Does CMS support setting the z byte?
-- gil
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