They ARE not. Code has to be written to use PARMDD and will therefore not crash production applications unexpectedly. Modifications to current PARM could crash current code, running well for decades based on ancient specs/assumptions.
Kees. -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Paul Gilmartin Sent: Friday, March 29, 2013 14:39 To: [email protected] Subject: Re: 32760? (was: PARMDD?) On Fri, 29 Mar 2013 09:08:36 -0400, Peter Relson wrote: >>I did not find Kevin Kelley's post entirely persuasive. This >>restriction long antedates 2 Kibyte pages, and the equation 8 x 4096 = >>32768 is thus historically irrelevant. > >Kevin was not trying to persuade. He was merely stating facts. The >number of pages is not the relevant part of the information. The >relevant limitation is the number of bytes that a halfword can support. > Don't attach too much significance to Gilmorespeak. I took it that he merely was not persuaded of the validity of the argument. >Aside from the BLKSIZE point, we would not consider a number about >32767 (for example 65528) as the limit, for compatibility reasons. >There are surely programs that use "LH" on the 2-byte length field >without subsequently clearing the high bytes and then rely on the value >that would misbehave if they land with a negative number. > A horrid example is HLASM. I tried it. Dog in the manger. Similar arguments could be made (and were in May, 2005) against PARM > 100 (overrun of traditional sized buffers) and PARM >256 (misbehavior of MVC). Fortunately, z/OS Core Technology Design did not find them persuasive when considering the PARM enhancement for z/OS 2.1. -- gil ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ******************************************************** For information, services and offers, please visit our web site: http://www.klm.com. This e-mail and any attachment may contain confidential and privileged material intended for the addressee only. If you are not the addressee, you are notified that no part of the e-mail or any attachment may be disclosed, copied or distributed, and that any other action related to this e-mail or attachment is strictly prohibited, and may be unlawful. If you have received this e-mail by error, please notify the sender immediately by return e-mail, and delete this message. Koninklijke Luchtvaart Maatschappij NV (KLM), its subsidiaries and/or its employees shall not be liable for the incorrect or incomplete transmission of this e-mail or any attachments, nor responsible for any delay in receipt. Koninklijke Luchtvaart Maatschappij N.V. (also known as KLM Royal Dutch Airlines) is registered in Amstelveen, The Netherlands, with registered number 33014286 ******************************************************** ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
