SNAX/HLS Application Programming Manual

Glossary
104707 Tandem Computers Incorporated Glossary–5
microcode. A code representing the instructions of an instruction set that is
implemented in a part of storage that is not program–addressable.
MICROCODE_FILES paragraph. A paragraph within the SYSGEN configuration file that is
used to indicate the location of the downloadable microcode for controllers and other
devices.
NAU. Network addressable unit.
NCP. Network control program.
network. A group of interconnected computer systems and devices, and the hardware
and software used to connect them.
node. In SNA, an endpoint of a link or junction common to two or more links in a
network. There are peripheral and subarea nodes. Nodes include host processors,
communication controllers, cluster controllers, or terminals. Nodes can vary in
routing and other functional capabilities.
node ID verification. A SNAX/XF switched–line feature that allows the Tandem system
to perform node ID verification by means of the SDLC XID commands and responses.
NonStop operation. A Tandem system behavior characterized by continued operation
even when a component fails, when equipment is being repaired or replaced, or while
new processors or peripheral devices are being added to the system. Legally used
only to describe the Tandem Nonstop system or its features, such as NonStop process
pairs.
nowait mode. In Guardian 90 file-system operations and in some APS operations, the
mode in which the called procedure initiates an I/O operation but does not wait for it
to complete before returning control to the caller. The application calls a separate
procedure (MFM_AWAITIOX_) to wait for the completion of the operation. See also
wait mode.
object. In Tandem terminology, an object is an entity that can be configured,
controlled, and inquired about by the operator. An addressed object is the object
specified in a command. A target object is the object that is acted upon by a command.
Addressed and target objects are usually the same.
packet–switching data network. A network that uses packet switching as a means of
transmitting data.
passthrough. A function of the SNAX/XF line access software that allows a 3270
terminal attached to a Tandem system to switch between Tandem and IBM
applications. Passthrough lets a host application program communicate with SNA
devices connected to a Tandem system as though the devices were connected to a
cluster controller.
Passthrough is enabled by configuration and startup procedures; it is never directly
invoked by application software. Passthrough can also be used to perform service or
management tasks that are incidental to SNA applications on a Tandem system.
passthrough logical unit. A gateway LU that has been configured to provide the
passthrough function.