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Why we can use only 255 steps and 3273 dd stat in one job

 
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shivsingla
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Joined: 14 Jul 2006
Posts: 15
Location: New Delhi

PostPosted: Sat Nov 22, 2008 1:54 pm    Post subject: Why we can use only 255 steps and 3273 dd stat in one job
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Hi All,
i am very new to this system , Can anybody tell me taht why we are using max 255 steps and 3273 statements in one job.
What is the reason behind that?



Thanks in advance
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enrico-sorichetti

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Joined: 14 Mar 2007
Posts: 10231
Location: italy

PostPosted: Sat Nov 22, 2008 2:08 pm    Post subject: Reply to: Why we can use only 255 steps and 3273 dd stat in
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because the designers planned it that way... icon_biggrin.gif
255 You should imagine it, it' s a one byte binary counter

the 3273 is a generic indicator, that' s true only if a ddname requires one VOLUME

look at the manual for detiled explanation and calculations
http://publibz.boulder.ibm.com/cgi-bin/bookmgr_OS390/BOOKS/iea2e281/4.6?ACTION=MATCHES&REQUEST=3273&TYPE=FUZZY&SHELF=IEA2BK81.bks&DT=20080128234357&CASE=&searchTopic=TOPIC&searchText=TEXT&searchIndex=INDEX&rank=RANK&ScrollTOP=FIRSTHIT#FIRSTHIT

search for TIOT or 3273
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shivsingla
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PostPosted: Sat Nov 22, 2008 3:20 pm    Post subject: Reply to: Why we can use only 255 steps and 3273 dd stat in
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thanks a lot.
it is very valuable
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Anuj Dhawan

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Joined: 22 Apr 2006
Posts: 6258
Location: Mumbai, India

PostPosted: Sat Nov 22, 2008 10:13 pm    Post subject:
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Hi,

The operating system maintains, by design, counters of 1 byte for the unique step ID (since a step can contain duplicate names, or no name). The max unsigned value that can be contained in 1 byte is x'FF' = 255.
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