I seem to recall early IBM (or maybe Amdahl) processors did not support origin zero dataspaces, so everyone was advised to use an origin of x'1000' on DSPSERV in early releases of MVS/ESA (I know that I did).
Obviously that restriction is gone now, and no-one in their right mind would write any new dataspace code now :-) Rob Scott Rocket Software Sent from Outlook for Android<https://aka.ms/AAb9ysg> ________________________________ From: IBM Mainframe Discussion List <[email protected]> on behalf of Martin Packer <[email protected]> Sent: Tuesday, 30 June 2026 17:50:30 To: [email protected] <[email protected]> Subject: Re: Zero-address-detection EXTERNAL EMAIL I have a vague recall that you couldn't do that in 3090-E but could in later machines. But I might be confusing that with something else. Cheers, Martin From: IBM Mainframe Discussion List <[email protected]> on behalf of Mark Henderson <[email protected]> Date: Tuesday, 30 June 2026 at 17:47 To: [email protected] <[email protected]> Subject: [EXTERNAL] Zero-address-detection I stumbled upon this in Ch 4 of POPS in connection with some strange results I experienced when trying to do a MVCL from a dataspace whose origin was zero. The doc is far from clear and, frankly, looks incomplete so I'm wondering whether the subject is better described elsewhere. Note, I understand I can change the dataspace origin but that's not the essence of the question. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN Unless otherwise stated above: IBM United Kingdom Limited Registered in England and Wales with number 741598 Registered office: Building C, IBM Hursley Office, Hursley Park Road, Winchester, Hampshire SO21 2JN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ================================ Rocket Software, Inc. and subsidiaries ? 77 Fourth Avenue, Waltham MA 02451 ? Main Office Toll Free Number: +1 855.577.4323 Contact Customer Support: https://my.rocketsoftware.com/RocketCommunity/RCEmailSupport Unsubscribe from Marketing Messages/Manage Your Subscription Preferences - http://www.rocketsoftware.com/manage-your-email-preferences Privacy Policy - http://www.rocketsoftware.com/company/legal/privacy-policy ================================ This communication and any attachments may contain confidential information of Rocket Software, Inc. All unauthorized use, disclosure or distribution is prohibited. If you are not the intended recipient, please notify Rocket Software immediately and destroy all copies of this communication. Thank you. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
