MPE/iX Glossary of Terms and Acronyms (32650-90893)

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Glossary of Terms
NS Common Services A group of network services including network file transfer
(NFT), network interprocess communication (NetIPC), remote process
management (RPM), and virtual terminal (VT).
$NULL Temporary file that is empty when used as input and meaningless when
used as output (the output essentially disappears into what is referred to
as the
bit bucket ). When referenced as an input file by a program, that
program receives only an end-of-file mark upon first access. When
referenced as an output file, the associated write request is accepted by
MPE/iX but no physical output is actually performed. $NULL can be used
to discard unneeded output from an executing program.
null value A value consisting only of binary zeros. Null values are neither blanks nor
ASCII zeros. They do not print.
object code Machine executable instructions. Object code is the result of source code
compilation.
octal The base eight numbering system, in which digits 0 through 7 are used.
One octal digit can be represented by three binary digits. Octal numbers
are preceded by a percent sign (for example, %775).
offline state The condition of a device when it is not available to the system, for
example, not under the direct control of the CPU.
$OLDPASS Temporary file created automatically when compiling is complete. It is
used to hold compiled code. This is a system-defined file and only one may
exist during a single job or session. This file results when the $NEWPASS
file closes.
online state The condition of a device when it is available to the system. An online
device allows the user to interact with the system.
open The act of obtaining access to a resource.
OPEN state The state of a file when it is being accessed by a user program or MPE/iX.
An OPEN input spoolfile occurs when data is being collected from the input
device (usually a terminal or tape drive). An OPEN output spoolfile is the
disk file being created by the output spooler.
Open Systems Interconnection (OSI) A seven-layer network architecture model
developed by the International Standards Organization (ISO). In the OSI
model, transmission and communication tasks are assigned to logically
distinct modules called layers. Each layer communicates with the layer
directly above and below it, and through the layers below it to its peer in
the remote computer. The OSI model defines the seven layers as the
following: 1. physical, 2. data link, 3. network, 4. transport, 5. session, 6.
presentation, 7. application.
operating system The software that operates the computer. It consists of programs such
as basic file and I/O manipulators. All subsystems run upon the operating
system.
operator command MPE/iX commands executed at the system console by the system
operator. Operator commands may be distributed to specific users at the