Jump to content

Execute Channel Program in Real Storage

Add links
From Wikipedia, the free encyclopedia
This is an old revision of this page, as edited by Peterh5322 (talk | contribs) at 16:56, 16 May 2011 (←Created page with '{{Mainframe I/O access methods}} In IBM mainframe operating systems, '''Execute Channel Program in Real Storage''' ('''EXCPVR''') is a supervisor call for l...'). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.
(diff) ← Previous revision | Latest revision (diff) | Newer revision → (diff)

In IBM mainframe operating systems, Execute Channel Program in Real Storage (EXCPVR) is a supervisor call for low-level device access, where the programmer is responsible for providing a list of device-specific channel commands to be executed by I/O channels, control units and devices. Additionally, the programmer is expected and required to ensure that the input/output data areas are in real storage and are "fixed".

EXCPVR may be viewed, in the abstract, as a V=R version of EXCP. The user of EXCPVR must be authorized.

EXCPVR's front-end is always in TCB mode, as EXCPVR is a Type 1 SVC. In MVS and subsequent instances of the OS, EXCPVR's back-end is always in SRB mode, but the back-end contains emulation code which allows the exits developed for earlier instances of the OS to function largely as before.

Retrieved from "https://en.wikipedia.org/w/index.php?title=Execute_Channel_Program_in_Real_Storage&oldid=429420178"