Both. The hardware part of it is described in the Principles of Operation. A control register bit, if on, enables LAP.
The software part of it is that at NIP the operating system (z/OS) turns the bit on. When LAP is enabled, any attempt by the running program to store into virtual addresses 0-511 of page 0 on a CPU is prevented. Bill Fairchild Rocket Software -----Original Message----- From: IBM Mainframe Discussion List [mailto:ibm-m...@bama.ua.edu] On Behalf Of Elardus Engelbrecht Sent: Thursday, December 16, 2010 9:54 AM To: IBM-MAIN@bama.ua.edu Subject: Re: Batch program to update CVTUSER Shmuel Metz (Seymour J.) wrote: >>Is low address protection a hardware or software feature? >Yes. For what? Hardware, Software or both? Groete / Greetings Elardus Engelbrecht ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
