In <[EMAIL PROTECTED]>, on 05/25/2005
at 06:43 AM, Bill Fairchild <[EMAIL PROTECTED]> said:
>Could be true. I don't know much about RECFM=U. At any rate, the
>access method subtracts the residual count from the max possible
>size to know what to store into DCBLRECL if RECFM=U.
That used to be the case way back when, except for OPTCD=C, but it
stopped being the case with SAM-E. Now the actual length is extracted
from the count area. A lot of processing takes place under the covers
to make that transparent.
>If N blocks are being read and one of them is short, the short block
>will cause the channel program to stop and the residual count will
>apply to the short block.
Perhaps for RECFM=FBS; certainly not for RECFM=FB.
>You can transfer more than one block per I/O request in reading a
>PDS member (as chained scheduling would do), but you can't use BSAM
>to do it.
Sure you can, and the documentation discusses how to do it. See if you
can find an old copy of SAM-E logic, or read the discussion of DASD
chained scheduling in SAM Logic for OS/VS2 R3.8 (MVS).
--
Shmuel (Seymour J.) Metz, SysProg and JOAT
ISO position; see <http://patriot.net/~shmuel/resume/brief.html>
We don't care. We don't have to care, we're Congress.
(S877: The Shut up and Eat Your spam act of 2003)
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