AmigaOS Manual: AmigaDOS Glossary

absolute path

A path that gives the full information for locating a file, including the volume or device name, any subdirectories, and the file name.

aliases

Alternative names for AmigaDOS commands. An alias can be used to abbreviate frequently used commands or replace standard command names with different names.

archive

A backup copy of one or more files or a whole volume.

argument

A filename, option, or other kind of information passed along with the command name on a command line. Also known as a parameter.

assign

To identify a path to a directory or file under an additional name. This defines logical devices used by the operating system, such as C: where AmigaDOS stores command files, or S: where scripts are stored.

background process

A process that does not open its own window for input or output and does not take over the parent Shell.

block

1. A contiguous series of bytes on a storage device (a disk block normally equals 512 bytes)

2. A contiguous part of a script/program file; for example, an IF-ENDIF block.

boot block

An area on a disk or PCMCIA card that contains boot code for the system to read when booting. The presence of a valid boot block on a disk or card makes it bootable.

Bridgeboard

A special hardware expansion board made by Commodore that makes Classic Amiga PC-compatible.

buffer

An area in RAM used for temporary data storage for disk or serial input/output or by some other operations.

cache memory

A storage area consisting of very fast RAM chips. It serves as a buffer between a fat CPU chip and a slower system memory. Built into systems with bigger processors.

Chip RAM

The part of the system RAM that the Amiga custom chips can access. All video and sound data is stored here.

circular link

A link that refers to a link that refers back to it.

Clipboard

An area in memory used to hold data in cut and paste operations.

command history

A list containing the most recently issued command lines. These command lines can be recalled, edited, and reissued.

command line interface (CLI)

See Shell.

comment

1. A line or part of a line that is not executed, but is included to document the operation of a program or script for future reference.

2. A short descriptive note that can be attached to any file using the FILENOTE command.

condition flag

A variable that indicates the condition on which a command ends.

console windows

Windows used by the Shell for text-oriented data input and output.

current directory

A Shell's current location in the directory structure, used as the default directory in which commands operate.

current window

The highlighted window that accepts input from the keyboard. A Shell window is current when it is opened.

cursor

The small rectangular highlighted box that indicates the positions in the current file at which the next character will appear.

data cache

Hardware feature present on 68030 and 68040 microprocessors that substantially speeds memory access.

delimiter characters

Characters that define the beginning and ending of an argument string. For example, in the ED text editor, ", /, \, !, :, +, and % are valid delimiters.

detach

To separate a program from the process in which it was invoked so that the process' Shell window can close before the program is finished.

device drivers

Files that provide functions needed for a device to function properly on the system.

directory caching

A file system option used to increase directory listing speed.

directory link

See Link.

disk operating system

A part of the operating system that is devoted to managing disks and files.

endless loop

A sequence of instructions in a computer program which loops endlessly.

escape sequence

A string of control characters, normally introduced by the Escape character. You can control the window format and font style with escape sequences.

extended commands

In the ED text editor, commands consisting of one or two characters that can be grouped together, introduced by the Esc key.

extension

A sequence of characters beginning with a period, such as .info, added to the end of a filename to identify the type of file.

fail limit

The limit at which a return code value terminates a sequence of non-interactive commands.

Fast RAM

Part of the system RAM to which custom chips do not have access. Since only the CPU and some peripheral devices have access to Fast RAM, it is considerably faster to use.

fence characters

Used in MEmacs to find the beginning and end of a program nest structure. Fence characters can be parentheses, brackets, braces, or angle brackets.

field

1. An on screen area in which a variable value is displayed or entered.

2. The screen area behind the text of a Workbench icon label. The color of the field can be changed with the Font editor.

file system

A part of the operating system that defines how information is stored on storage devices. This includes file headers, data sectors, subdirectory headers, and bitmaps that indicate which sectors on a disk are already occupied and which are free.

global vector (Globe Vec)

A mount parameter needed by some devices.

hexadecimal

The base 16 numbering system.

hierarchical file system

A file system that allows directories to contain other directories, as well as files.

immediate commands

Commands in the ED text editor are executed as soon as you press the associated key combination.

instruction cache

A type of memory in the 68020, 68030, and 68040 microprocessors that allows instructions to execute more quickly.

interactive listing mode

A mode of the DIR command that stops after each name in a directory listing to display a question mark at which commands controlling the listing can be entered.

internal commands

Commands that are built into the Shell. These do not need to be loaded from disk to use.

interprocess communication (IPC)

The mechanism by which two programs pass data to and from each other.

kernel module

A library which can be attached to the Kickstart. See Kicklayout.

Kickstart

Software which is read from disk and used for booting the Amiga. Kickstart also refers to the operating system part stored in the write-protected RAM.

line windows

Subsections of the line on which the EDIT line editor executes all subsequent commands.

link

A file or directory that is a pointer to another file or directory on a disk. When an application or command calls the initial file or directory the linked file or directory is used. (Also called a hard link.)

logical device

An assigned directory or software device that is referred to by a device, but points to a directory or device handler.

MountList

A text file in the DEVS: directory that contains information about connected or logically defined devices. The MOUNT command uses this information to activate devices.

multitasking

The ability to run more than one program simultaneously. For example, on the Amiga you can start several programs from a single Shell window using the RUN command.

nesting

Multiple levels of IF statements within scripts or programs or multiple levels of subdirectories within directories.

non-detached programs

Commands that occupy the Shell while processing, preventing the Shell's use or closure until completion.

octal

The base 8 numbering system.

operating system

Underlying software that controls the computer's functions.

path

Information that provides the system with the location of a particular file. This can include a volume or drive name and subdirectory names. See also search path.

pattern matching

A way of searching files and directories that match a specified pattern; this can be done with wildcard characters.

PCMCIA

Personal Computer Memory Card International Association, an organization that establishes standards for memory card slot devices.

pipe

An Interprocess Communication (IPC) mechanism for sending the output of one command as input to another.

process

An Amiga operating system task that can communicate with AmigaDOS to access files. Each process is identified with a number that can be displayed using the STATUS command.

prompt

A special customizable text string that always appears at the start of a Shell window line to indicate that the system is ready to receive another command line.

protection bits

Attributes that indicate a file's type and the operations permitted on it. Use the LIST command to display the protection bits associated with a file.

pure

Describes a command or program that can be made resident. If a file is pure, the p protection bit is set.

redirection

The process of sending command input or output to a destination other than the Shell; for example, to a file.

re-entrant commands

Commands that support independent use by two or more programs simultaneously.

Re-executable commands

Commands that do not have to be reloaded to be executed more than once.

resident

Commands stored in memory so that they do not have to be reloaded each time they are used. These commands should be pure.

return code

A number returned to the Shell from a command at completion to indicate its success or failure.

root

The main directory of a disk, containing all its files and/or subdirectories.

SCSI (Small Computer System Interface)

An interface standard for connecting peripheral devices to a computer system. (This is pronounced "scuzzy.")

search path

A series of directories in which AmigaDOS looks for commands that are entered without paths. The default search path includes the C: directory, the current directory, and several other directories specified in the standard Startup-sequence.

sector

The smallest storage unit on a disk, usually 512 bytes.

Shell

A text-oriented user interface in which you type in command lines and receive output in a special Shell or console window. Also called CLI (Command Line Interface).

soft link

A file or directory link that can span multiple devices or volumes. This is not currently supported on the Amiga.

spawn window

An AmigaDOS Shell window opened from MEmacs using the MEmacs New-CLI command. AmigaDOS commands entered into the spawn window do not interface with MEmacs.

stack

An area of the computer's memory that is set aside by a program for intermediate storage. Allocating insufficient stack space can cause program failure.

Startup-sequence

A special script file that is automatically executed when the Amiga is booted.

string

A series of text characters treated as a unit, such as a message printed by ECHO. A string usually requires delimiter characters, such as spaces or quotation marks, to mark its beginning and end.

template

A string that defines a Shell command's arguments and argument types.

timestamp

The date and time associated with a file. This reflects when the file was created or the date and time that changes to the file were last saved.

User-startup

A special script file that you create to customize your system's startup. If a User-startup file exists, it is automatically executed by the Startup-sequence.

wildcard characters

Characters with special meaning when used in file name specifications. These characters are used in pattern matching operations.

Workbench

The Amiga's icon-based graphic user interface (GUI).