Glossary

account

See login account.

address dial

See SCSI address dial.

administrator

The person who can use the most privileged account, root. This person must have a personal login account for daily use, but when there are serious system problems to correct, the person logs in to the root account to change system information.

The administrator has all the capabilities of a privileged user, plus the capability to change information in the root account (such as the password) and to log in to an IRIX shell as root. Because there is only one root account, there is only one administrator per system. The root entry in /etc/passwd on a particular system includes the name of the system's administrator so other users know whom to contact for help.

Seealso network administrator.

back up

To copy a certain set of files and directories from your hard disk to a tape or other media.

backup tape

A tape that contains a copy of a set of files and directories that are on your hard disk. A full backup tape contains a copy of all files and directories, including the IRIX operating system, that are on your hard disk.

baud rate

A term used for the speed (calculated as bits per second) at which the computer sends information to a serial device, such as a modem or terminal.

boot

To start up the system by turning on the workstation and monitor; the system is fully booted when you see the console login prompt.

CD-ROM (CD)

A flat metallic disk that contains information that you can view and copy onto your own hard disk; you cannot change or add to the information on the CD-ROM. CD-ROM is short for "compact disc: read-only memory".

centralized network

A network where a central server controls services and information; the server is maintained by one or more individuals called network administrators. On a centralized network that uses NIS, this server is called the NIS master, and all other systems on the network are called NIS clients. Seealso network administrator, NIS, NIS client, NIS domain, and NIS master.

configuration file

A system file that you customize to change the way your system behaves. Such files are sometimes referred to as customization files.

connector

Hardware at the end of a cable that lets you fasten the cable to an outlet, port, or other connector.

console

The port (Port 1, or /dev/ttyd1) on which system messages are displayed.

CPU module

The printed circuit board within the system chassis on which the central processing unit (CPU) is mounted. The CPU module is detachable from the motherboard. See Chapter 9 for information on locating, removing, and replacing the CPU module.

current working directory

The directory within the filesystem in which you are currently located when you are working in a shell window.

cursor

A special character that indicates where on the screen input appears when entered from the keyboard. On character-based (serial) terminals, the cursor is usually either a rectangular block or an underscore.

DAT (digital audio tape)

A magnetic tape from which you can read and to which you can copy audio and digital information.

default printer

The printer to which the system directs a print request if you do not specify a printer when you make the request. You set the default printer using the lpadmin(1M) command.

default subsystems

Portions of a product that are installed automatically if you do not customize a product installation.

defaults

A set of behaviors that Silicon Graphics specifies on every system. You can later change these specifications, which range from the list of user accounts on the system to what type of drive you want to use to install new software.

diagnostics

A series of tests that check all hardware components of your system.

directory

A special file in the filesystem that contains other files and directories.

disk resource

Any disk (hard, CD-ROM, floppy, or floptical) that you can access either because it is physically attached to the server with a cable or because it is available over the network using NFS®. See also NFS.

disk use

The percentage of space on a disk that contains information.

drive

A hardware device that lets you access information on various forms of media, such as hard, floppy, and CD-ROM disks, and magnetic tapes.

drive address

See SCSI address.

export

To use NFS software to make all or part of your filesystem available to other users and systems on the network.

external device

Any piece of hardware that is attached to the system with a cable.

female connector

A connector that has indentations or holes into which you plug a male connector. An example of a female connector is an electrical wall outlet that accepts an electrical plug.

field

An area on the screen in which you can type text.

file

A container in which you store information such as text, programs, or images you create using an application.

filesystem

A hierarchy of directories and files. Directories contain other directories and files; files cannot contain directories. The root (/) directory is at the top of the hierarchy.

floptical disk drive

A disk drive that combines magnetic recording methods with an optical servo-mechanism that allows large amounts of information to be stored in a small amount of space.

GIO option boards

GIO standards for graphics I/O, but the GIO bus supports a variety of option boards such as network and fast SCSI-2. GIO option boards connect to the GIO32-bis expansion slots on the IOPLUS or GIO Slot Extender boards in the Challenge S server.

GIO64 bus

The main system bus that connects the CPU, memory, I/O, and GIO expansion slots.

gracefully halt

Also referred to as "graceful shutdown." The process of stopping the operating system (IRIX), including closing open files and halting processes, before system power is turned off. This can be done through software or by turning off the system using the power button on the front panel. See the IRIX Advanced Site and Server Administration Guide for complete information about halting the system.

grounded electrical outlet

An electrical wall outlet that accepts a plug that has a grounding prong. In the USA, all three-pronged outlets are grounded.

group ID

A number that uniquely identifies a group of users on the system. Using group IDs allows specific groups of users to share files among themselves, but maintain privacy from other users on the system and on the network.

handshake

The protocol that controls the flow of information between a workstation and a printer or any other peripheral. A hardware handshake uses only cable wires and pins to control the flow. A software handshake (also called xon-xoff flow control) uses a combination of pins, wires, and software.

home directory

The directory into which IRIX places you each time you log in. It is specified in your login account; you own this directory and, typically, all its contents.

host

Any system connected to the network.

hostname

The name that uniquely identifies each host (system) on the network.

human factors guidelines

A set of standards and suggestions for making your working environment more comfortable and healthy.

icon

A small picture used to label a part of the system, such as a connector on the back of the system.

internal drive

A drive that fits inside the system chassis and connects to an internal port; it is never connected with a cable to a visible external port.

IP address

The Internet Protocol number that uniquely identifies each host (system) on the network.

IRIS

A workstation manufactured by Silicon Graphics, Inc.

IRIX

The Silicon Graphics version of the UNIX operating system. Seealso system software.

ISDN (integrated services digital network) port

The Challenge S server has a single ISDN basic rate interface that supports point-to-point protocol (PPP). PPP enables TCP/IP networking across ISDN B-channels.

Kb (Kilobit)

A standard unit for measuring data transfer rates. One kilobit is 1024 bits. Seealso KB (kilobyte).

KB (Kilobyte)

A standard unit for measuring the information storage capacity of disks and memory (RAM and ROM); 1024 bytes make one kilobyte.

LED (Light Emitting Diode)

A light on a piece of hardware that indicates status or error conditions.

log in

To give the system your login name so you can start a session on the server or another host.

log out

To end a session on the server or another host.

login account

A database of information about each user that, at the minimum, consists of login name, user ID, and a home directory.

login name

A name that uniquely identifies a user to the system.

login screen

The screen that you see after powering on the system, before you can access files and directories. The default login screen usually displays the name of the system and prompts for a login account name.

male connector

A connector that has raised edges, pins, or other protruding parts that you plug into a female connector. An example of a male connector is an electrical plug that you plug into a wall outlet.

man page

See reference page.

MB (Megabyte)

A standard unit for measuring the information storage capacity of disks and memory (RAM and ROM); 1024 kilobytes make one megabyte.

megatransfers

The number of million operations per bus cycle. An operation is either 8 or 16 bits in size. Megatransfers are based on a bus's burst data rate.

monitor

A hardware device that displays the images, windows, and text with which you interact to use a system. It is also called a video display terminal (VDT).

mount

To make a filesystem that is stored on a local or remote disk resource accessible from a specific directory on your workstation.

mount point

The directory on your workstation from which you access information that is stored on a local or remote disk resource.

network

A group of computers and other devices (such as printers) that can communicate with each other electronically to transfer and share information.

network administrator

The individual(s) responsible for setting up, maintaining, and troubleshooting the network, and for supplying setup information to system administrators of each system.

NFS (network filesystem)

A networking software option that lets you access files and directories that reside on the disks of other workstations as if they resided on a local disk in your own workstation.

null modem

A serial communications term that indicates that the transmit data (TXD) and receive data (RXD) signals are crossed, or "nulled," in a cable, connector, or adapter. A null modem cable, connector, or adapter connects the TXD signal of one device to the RXD signal of another other device.

option drive

Any internal drive other than the system disk. Option drives include floppy disk drives, floptical disk drives, secondary hard disk drives, or DAT drives.

parallel device

Any hardware device that requires a parallel cable connection to communicate with the workstation. A parallel interface transfers bits of information down a number of wires simultaneously.

parallel port

An connector on the workstation to which you attach external parallel devices. A parallel interface transfers bits of information down a number of wires simultaneously. Compare with serial port.

password

A combination of letters and/or numbers that only you know; it is an optional element of your login account. If you specify a password for your account, you must type it after your login name before the system will allow you to access files and directories.

pathname

The list of directories that leads you from the root (/) directory to a specific file or directory in the filesystem.

peripheral

A hardware device, such as a tape drive, that adds more functionality to the basic workstation. See also external devices and internal drives.

port

A connector on the workstation to which you attach cable connectors.

power cable

The cable that connects the workstation to a grounded electrical outlet.

power off

To turn off the power switches on the system chassis.

power on

To turn on the power switches on the system chassis.

power-on diagnostics

A series of tests that automatically check hardware components of your system each time you turn it on.

power supply

The piece of hardware within the chassis that transforms wall current to the appropriate levels for the system hardware. It also contains the power switch, reset button, and fan.

PROM monitor

The interface that you use to communicate with the system after it is powered up, but before it is booted up and running IRIX.

prompt

A character or word that the system displays in an IRIX shell that indicates the system is ready to accept commands. The default prompt for regular user accounts is %; the default prompt for the root account is #.

quit

To stop running an application.

reference page

An online document that describes how to use a particular IRIX command. You can view reference pages using the man (manual page) command.

remote drive, disk, filesystem, or printer

A hardware device or the information or media it contains that you can access across the network. It is not physically connected to your workstation. The opposite of local workstation or server.

reset button

A physical button on the server that you press to immediately halt all system processes, flush memory, and reboot the system. You should never press this button while IRIX is running, unless all attempts to shut down the system using software have failed. See also shut down.

restore (files)

To copy files that once resided on your hard disk from another disk or a tape back onto your hard disk.

root account

The standard IRIX login account reserved for use by the system administrator. This account's home directory is the root (/) directory of the filesystem; the user of the root account has full access to the entire filesystem (that is, can change and delete any file or directory). The user of this account is sometimes referred to as the superuser.

root (/) directory

The directory at the top of the filesystem hierarchy.

screen

The portion of a monitor or terminal that displays information.

SCSI (small computer system interface)

Pronounced "scuzzy." SCSI is a high speed input/output specification originally developed for small computers, but now used on a variety of systems.

SCSI address

A number from one to fifteen that uniquely identifies a SCSI device to a system. No two SCSI devices that are physically connected to the same SCSI channel can have the same SCSI address.

SCSI address dial

A small plastic dial connected to every external SCSI device supplied by Silicon Graphics, Inc. Click on its small buttons to select a SCSI address for a new SCSI device.

SCSI bus line

The combined length of all internal and external SCSI cables in a system.

SCSI cable

A cable that connects a SCSI device to a SCSI port on a workstation.

SCSI channel

Part of the addressing scheme used to access SCSI devices. The Challenge S server contains three SCSI channels: 0, 4, and 5. Each SCSI device on a SCSI channel is assigned a unique address (sometimes called a unit number). Seealso SCSI address.

SCSI device

A hardware device that uses the Small Computer System Interface (SCSI) protocol to communicate with the system. Hard disk, floppy disk, floptical disk, CD-ROM, and tape drives are all SCSI devices.

SCSI terminator

A cap that you plug into any open SCSI port on a SCSI bus line. SCSI devices on a SCSI bus line will not work properly unless all SCSI ports on that bus line are occupied by either a cable or terminator.

serial device

Any hardware device that requires a serial cable connection to communicate with the workstation.

serial port

An outlet on the workstation to which you connect external serial devices. Serial ports send information one bit at a time. Compare with parallel port.

server

A system that other systems on the network access to use its disk space, software, or services.

shell

A process that controls other processes on the IRIX system. You type commands to the Challenge S server at a shell prompt, either on a character-based terminal or in a shell window on a remote graphics workstation.

shielded cable

A cable with a protective covering that reduces the possibility of interference with radio, television, and other devices.

shut down

To properly close all files, log out, and bring the workstation to a state where you can safely power it off.

SIMM (single inline memory module)

A small printed circuit board with several chips that contain random-access memory (RAM).

SIMM socket

A long, thin, female connector located on the system motherboard into which you insert a SIMM.

software option

Any software product that you buy from Silicon Graphics other than the standard system software that comes on your system disk.

stand-alone system

A system that is not connected to a network.

static electricity

Whenever your body comes in physical contact with metal parts (including printed circuit boards) of computer equipment the potential exists for you to feel an electrical shock (electrostatic discharge or ESD), which could damage the equipment. To prevent this you must always wear a wrist strap when working with the internal parts of a workstation.

subsystem

A portion of a software product. Each product consists of several subsystems; some are required and some are optional.

superuser

An alternate name for the user of the root login account. See also system administrator.

system

All of the hardware and software operating together that make up a workstation or server.

system administration

The tasks associated with setting up, maintaining, and troubleshooting a networked or standalone system.

system crash

When the IRIX operating system fails and the system will not accept any input (other than pressing the reset button or the power button).

system disk

The physical disk that contains the standard IRIX operating system software.

system software

The standard IRIX operating system software and Silicon Graphics tools. They are provided on the system disk and on the tape or CD-ROM that you use in the event of a system crash.

TCP/IP

Stands for transmission control protocol/internet protocol. A set of networking protocols for local area networks (LANs) and wide area networks (WANs).

thumbscrew

The ridged knob attached to a screw in a cable connector. You turn it to secure the connector to an outlet.

unmount

To make a filesystem that is accessible from a specific directory on the server temporarily unaccessible.

upgrade (hardware)

Hardware that you add to the system to increase performance or capabilities.

user ID

A number that uniquely identifies a user to the system. See also group ID.

workstation

A computer system that provides a CPU, keyboard, mouse, and graphics hardware. A workstation may have a system disk and option disks, or it may be diskless (relying entirely on a server for data storage).

wrist strap

A coiled cable with a loop for your wrist at one end and an alligator clip at the other, used for grounding the user. Whenever you work on the internal components of the system you should fasten the clip to a metal part of the chassis and place the loop around your wrist. This helps avoid electrical shocks to yourself and the components. See also static electricity.