Guardian Programmer's Guide

Table Of Contents
Glossary
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Glossary - 22
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page. A unit of virtual storage for disks and CPU memory. The size of a disk page is 2048
bytes. The size of a memory page varies depending on the CPU type and the software
release.
page mode. A mode of communication between a terminal and its I/O process in which the
terminal stores up to a full page of data (1920 bytes) in its own memory before sending
the page to the I/O process. Contrast with conversational mode.
PAID. See process access ID (PAID).
PARAM. An association of an ASCII value with a parameter name made by the TACL
PARAM command. You can use PARAMs to pass parameter values to processes.
partially qualified file name. A file name in which only the right-hand file-name parts are
specified. The remaining parts of the file name assume default values. Contrast with
fully qualified file name.
pathname. In the Open System Services (OSS) file system and Network File System
(NFS), the string of characters that uniquely identifies a file within its file system. A
pathname can be either relative or absolute. See also ISO/IEC IS 9945-1:1990
(ANSI/IEEE Std. 1003.1-1990 or POSIX.1), Clause 2.2.2.57.
pathname component. See filename.
partitioned file. A logical file made up of several partitions that can reside on different disks.
Generic key values determine the partition on which a given record resides.
PCB. See process control block (PCB).
permanent disk file. A file that remains on disk until it is explicitly purged.
persistent process. A process that must always be either waiting, ready, or executing.
These processes are usually controlled by a monitor process that checks on the status
of persistent processes and restarts them if necessary.
PFS. See process file segment (PFS).
physical memory. The semiconductor memory that is part of every CPU.
PIN. See process identification number (PIN).
primary extent. The first contiguous area of disk allocated to a file. See also secondary
extent.
primary key. A unique value that identifies a record in a structured disk file.
primary path. The path between the CPU and controller that is currently being used.
priority. An indication of the precedence with which a process gains access to the
instruction processing unit.