No, it was possible to implement this downward compatible, because there was unused space in the 32-bit registers that could be used for 31-bit, while 24-bit remained supported and for 64 bit, registers were expanded while supporting the old registers. This was possible because the hardware/architecture controlled the registers, while MVS did not control the halfwords in all the places where they were used.
Kees. -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of R.S. Sent: 16 December, 2016 15:07 To: [email protected] Subject: Re: 32760 vs. 32768 IMHO "more impossible" was to move from 24 to 31 bit or to 64 bit addressing. Not to mention 1TB volumes ;-) Regards -- Radoslaw Skorupka Lodz, Poland W dniu 2016-12-16 o 14:50, Vernooij, Kees (ITOPT1) - KLM pisze: > I think that the effort to track down all the halfwords and convert them plus > the supporting software, was considered impossible. Applying disk efficiency > with half-track blocksizes was much easier. > > Kees. > > -----Original Message----- > From: IBM Mainframe Discussion List [mailto:[email protected]] On > Behalf Of R.S. > Sent: 16 December, 2016 14:46 > To: [email protected] > Subject: Re: 32760 vs. 32768 > > W dniu 2016-12-16 o 14:37, Tom Marchant pisze: >> On Fri, 16 Dec 2016 07:41:59 -0500, Tony Thigpen wrote: >> >>> Recently, I had a file transfer issue between z/VSE and z/OS because VSE >>> support block lengths of 32768 (true 32k) while z/OS only supports 32760 >>> (32k-8). >> In MVS, LRECL and BLKSIZE are stored as signed halfword values. >> > IMHO more interesting question is why the constraint was not relieved. > The need for that occured (AFAIR) in the times of 3380 DASD, that means > 1981 or so. > Many problems would be solved. SDB, LRECL=X, SMF archives, RECFM=VBS, > better performance and disk usage, etc. > --- Treść tej wiadomości może zawierać informacje prawnie chronione Banku przeznaczone wyłącznie do użytku służbowego adresata. Odbiorcą może być jedynie jej adresat z wyłączeniem dostępu osób trzecich. Jeżeli nie jesteś adresatem niniejszej wiadomości lub pracownikiem upoważnionym do jej przekazania adresatowi, informujemy, że jej rozpowszechnianie, kopiowanie, rozprowadzanie lub inne działanie o podobnym charakterze jest prawnie zabronione i może być karalne. Jeżeli otrzymałeś tę wiadomość omyłkowo, prosimy niezwłocznie zawiadomić nadawcę wysyłając odpowiedź oraz trwale usunąć tę wiadomość włączając w to wszelkie jej kopie wydrukowane lub zapisane na dysku. This e-mail may contain legally privileged information of the Bank and is intended solely for business use of the addressee. This e-mail may only be received by the addressee and may not be disclosed to any third parties. If you are not the intended addressee of this e-mail or the employee authorized to forward it to the addressee, be advised that any dissemination, copying, distribution or any other similar activity is legally prohibited and may be punishable. If you received this e-mail by mistake please advise the sender immediately by using the reply facility in your e-mail software and delete permanently this e-mail including any copies of it either printed or saved to hard drive. mBank S.A. z siedzibą w Warszawie, ul. Senatorska 18, 00-950 Warszawa, www.mBank.pl, e-mail: [email protected] Sąd Rejonowy dla m. st. Warszawy XII Wydział Gospodarczy Krajowego Rejestru Sądowego, nr rejestru przedsiębiorców KRS 0000025237, NIP: 526-021-50-88. Według stanu na dzień 01.01.2016 r. kapitał zakładowy mBanku S.A. (w całości wpłacony) wynosi 168.955.696 złotych. ---------------------------------------------------------------------- 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
