DEC 3000 800, Owner'S Manual

Page: 287 / 318

environment variable
A global data structure that can be accessed only from console
mode. The setting of these data structures determines how a
system starts up, boots operating system software, and operates.
error correction code (ECC)
Code that carries out an automatic error correction by
performing a bit-wise exclusive-OR (XOR) operation on the
transferred data and using the result to generate a correction
mask. Compare with parity.
error message number
A number that appears on the error line representing a
particular system or component problem.
Ethernet
A local area network (LAN) or wide area network (WAN) that
connects (by coaxial cable) multiple computers that are running
a variety of network operating systems. Ethernet transmits
10 megabits per second and does not require switching logic or
control by a central computer.
Ethernet controller
An interface unit that connects a system to the Ethernet.
Ethernet hardware address
The unique Ethernet physical address associated with a
particular Ethernet communications controller.
Ethernet ports
The connectors on the system unit through which the Ethernet
is connected to the system.
Ethernet subsystem
The Ethernet controller chip built into the system module.
expansion box
An external unit connected to the system to add additional I/O
slots or storage capacity.
Glossary–13