Millennium Time Capsule/AC2000.BIN/disks/ac10disk/atozbook/w.txt

Text File | 1998-06-10 | 11.0 KB | 289 lines

                             "The Atari A to Z"
                              by Mark S Baines
                      Copyright (c) 1998 Mark S Baines
                             All Rights Reserved


       YOU MUST READ "READ_ME.NOW" BEFORE YOU LOOK AT ANY OF THIS FILE
*****************************************************************************


W


Wafer
A very thin polished section of silicon crystal from which the silicon 'chips'
of semiconductors are made.


WAIS
Wide Area Information Service. A powerful system for searching for information
held in public databases across the Internet.


Wait states
Idle CPU clock cycles waiting for the data and instructions to come from slow
RAM chips. This time can be lessened by a small fast static RAM cache for the
CPU. With a ST with DRAM with an access time of 120 ns or less and an 8 MHz
MC68000 there are no wait states, as each ST clock cycle is 125 ns long and
most operations on a 68000 take four or more cycles to complete. All this
means that ST DRAM is fast enough for the processor and that fitting DRAM
chips faster than 120 ns makes no difference to the speed of the computer at
all. Even on a 16 MHz Mega STE, the RAM is still accessed at 8 MHz and so slow
memory can still be used.


Waiting state
The condition in which the instructions of an active program in a
multiprogramming system are being ignored in preference to another program.


Waiting time
The time when a program or functional unit is in a waiting state.


WAN
Wide Area Network. Computers or terminals indirectly connected together over
large distances usually using telecommunications links to form a network
sharing some or all of the same resources, such as programs and data as well
as disks, printers and even memory. Each computer or point of connection is
called a node.


Wand
A hand-held input device to read bar codes or magnetic strips often used at
point-of-sales terminals.


Warm boot
Making a computer system, which is already powered up, operational usually by
loading the operating system. A warm boot implies that the system is not fully
initialized as with a cold boot and that some system software is already
present. On micros it often means a reset and re-boot.


Wave
A repeated variation in voltage, sound, light etc. that is capable of
transferring energy between two points, such as a carrier wave.


WD1772
The floppy disk controller chip used in the ST-Falcon made by Western Digital,
derived from the FD1790 family and supplied in a 28-pin DIL package. It is
only capable of controlling two floppy disk drives with either single-sided or
double-sided double density disks with a capacity of around 720 K. The WD1772
provides all the signals for the control of a disk drive except for the drive
and side select signals which come from the YM-2149 sound chip. When high
density disks were introduced on the TT and Mega STE with TOS 2.06 and 3.06
the standard WD1772 was inadequate only being capable of handling a clock
signal up to 12 MHz although some 02-02 types could handle 16 MHz. For high
density and extra density disks, a clock signal of 16 MHz and 32 MHz is
necessary and the WD1772 AJAX controller was designed for this purpose. See
AJAX.


Weight
A value by which a digit is multiplied depending on its position in a number
or string. In positional representation systems, such as decimal and binary,
the weights of digits in adjacent positions differs by the amount of the radix
or base. In the decimal number 27, the 2 has a weight of ten and the 7 a
weight of one. In binary %101, the first leftmost 1 has a weight of four, the
0 a weight of two and the least significant 1 a weight of one.


Weighting
A value by which a digit is to be multiplied.


Whetstone
A unit of computer throughput.


White noise
Noise without a distinctive frequency pattern, such as with radio reception.


Whitespace
The characters included in a text file shown on screen that have no screen
representation, such as the space and control characters. Also, in print, the
amount of paper without type or graphics, as important to the layout of a page
as the 'black' areas.


WHY
What Have You. Commonly used shorthand in e-mail and other messages. Might be
seen in a message from a person wishing to part-exchange or swap something.


Wide area network
See WAN.


Wildcards
A single character entered into a command line string that may stand for one
or more other characters when performing a search operation. Normally, the ?
means any single character (or none) whilst a * stands for any number of
different characters, for instance *.DOC would represent any file with the
.DOC extender, whilst TEST_?.C would match TEST_1.C, TEST_A.C and TEST_.C but
not TEST.C.


WIMP
Windows, Icons, Mouse, Pull-down menus. (Often interpreted as 'Windows, Icons,
Menus, Pointers'). A graphical user interface with windows and menus,
predominately mouse controlled and characterized by the use of file dragging
techniques and a 'Trash Can' for file deletion which particularly distinguish
it from other GUI environments. The aim of a WIMP environment is to make the
operation of a computer and a program as intuitive as possible to a user,
using real-life analogies of working, such as dragging a file to a trash can
to delete it. If programs are written to the guidelines of the WIMP system
then all programs should be controlled and behave in a similar manner thus
increasing the learning rate and productivity of a user. GEM, OS/2 v2, OS/2
WARP on the PC and the operating system front ends of the Apple Mac and Acorn
Archimedes are true WIMP environments. It has been argued that Windows on the
PC is not truly WIMP, lacking many WIMP traditional features should be
classified as a GUI.


Winchester
An IBM originated name denoting a type of magnetic disk unit with one or more
fixed hard disks with heads that land and take off from the disk surface and
stored in a hermetically sealed case. Winchester disks are typically, the hard
disks of microcomputers. See Hard disk.


Window
A period that has time significance for the occurrence of some event. In
computer graphics, WIMP and some GUI environment systems, an area within a
frame in which the output of a program is written and the user input takes
place - a virtual screen or workstation for a program. Many windows can be
present on the display screen at once, either all being active in a
multitasking system, such as in MultiTOS or only the topmost in a
singletasking system, such as TOS.


Word
A fixed number of bits that the computer hardware can transfer and manipulate
as a unit within storage and the central processor, usually 8, 16, 24 or 32.
The ST has a word length of sixteen being the width of the MC68000 data bus.
The TT and Falcon030 have a word length of 32 bits. Also, a significant unit
of a language usually delineated with spaces or punctuation marks.


Word length
The number of bits in a word, sixteen bits on a ST.


Word processing
The use of a computer program to assist in the preparation and printing of
short-run printed documents. Typically, it allows the user to enter,
manipulate, edit and print the text and store it for later retrieval and
reference. Search and replace, margin justification, mail merge, spell
checking, automatic page numbering, index and contents page generation,
standard paragraphs and print control are some of the features of a word
processor. Traditionally, a word processor uses a printer's own built-in fonts
and styles and prints its document in text mode rather than the graphics mode
associated with DTP. However, as word processing programs become more
sophisticated and use many of the features of DTP programs, this distinction
is increasingly becoming unclear and are better described as document
processors.


Word wrap
A text editing function that automatically moves a word that crosses the
text's right margin on to the next line so that the maximum line length is not
exceeded and the word is not split (except by hyphenation).


World Wide Web
See WWW.


Work area
A unit of memory or disk space allocated to a program for the temporary
storage of results, buffers and other processing needs.


Work file
A temporary disk file used by a program whilst running. A scratch file.


Workstation
A VDU terminal, often of a multi-user, multitasking system or local network
where work is done.


WORM
Write Once, Read Many times. A term that refers to storage devices that can be
written to only once. Some optical storage devices that use a laser to write
data by permanently changing the specially coated surface of a disk or tape
come into this category.


WP
Word Processing.


WPM
Words Per Minute. A measurement of typing speed.


Write
To place data in a particular location of computer storage. Also, to produce
program source code.


Write enable
A signal that must be 'true' before a write operation can be performed, such
as the switch within a floppy disk drive that detects whether the write-
protect tab is open.


Write head
An electromagnetic element used to record data on a magnetizable surface
medium. It is common to find the write and read heads combined into a single
unit.


Write inhibit
A term applied to a signal, flag or device that prevents writing.


Write-protect tab
A hole or notch in a floppy disk which, when present and detected by the disk
drive, prevents all write operations to it including file deletion. The hole
on a 3.5 inch floppy disk is that at the bottom left-hand corner as inserted
into the drive. Moving the tab so that the hole is closed enables the disk
drive to write to the disk.


Write verify
When data is written to a disk it is verified by the operating system, that
is, it is read back from the disk and checked against the original. As this
operation takes time, it is a common practice to turn off this check when
using disks thus speeding up their operation. Although generally safe to do
so, it is not recommended with important data and poor quality disks and
drives.


WWW
World Wide Web. A hypertext-based system used to explore the Internet and the
information and resources contained therein. With suitable software a user can
select a link which connects him to a remote system where that resource
resides. The connections and searching for information and resources are done
transparently to the user. The WWW developed from gopher type systems. See
Internet, Gopher, WAIS.


WYSIWYG
What You See Is What You Get. A term that refers to the ability of a program
(such as in DTP) to closely represent on the screen what will be printed. The
varying definitions of this principle and the differing resolutions between
that of the screen and that of the printer make true WYSIWYG impossible with
present technology, although the better systems come reasonably close.


W
40 entries
EOF