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A GLOSSARY FOR BEGINNERS
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ACCESS TIME. Time required for computer to locate and read data
from disk or memory. Average access time for a hard drive is
determined by time required for head to locate and move to the
specified track and for disk to spin around until desired data
sector is beneath head.
ADAPTER BOARDS or CARDS. Plug in circuit boards which can
contain functions such as modems, monitor display circuits, FAX
capabilities, floppy or hard disk control circuits and other
functions. Adapter boards are plugged into empty slots on the
main "motherboard" of the computer.
ADDRESS. Location of a specific piece of computer information in
computer RAM memory. Also a specific cell location in a spreadsheet
(e.g., address A22 in a spreadsheet: meaning the cell at
intersection of column A, row 22.)
ALGORITHM. A sequence of software steps which represent a
formula, method or sequence of operations to accomplish a task.
ALPHANUMERIC. Containing both letters and numbers.
ALT KEY. The key labeled Alt at the left of your keyboard.
This key is often used by holding down Alt and hitting another
key.
ANSI. Acronym for American National Standards Institute which
promulgates electronic and computing standards. ANSI is also
used in connection with the small software program contained
within DOS called ANSI.SYS which can control screen color,
keyboard functions and cursor position.
APPLICATION SOFTWARE. Computer programs that perform high level
tasks for users. For example, spreadsheets, databases or word
processing.
ASCII. This acronym stands for American Standard Code for
Information Interchange and represents a standard file format
which uses numbers to represent keyboard characters. In the
ASCII system, binary numbers from 0 to 127 represent upper and
lowercase letters of the alphabet. A block of eight zeros and
ones represent these characters. ASCII files, a related concept,
are text files which DO NOT contain extraneous codes or control
characters and are PURELY text. Word processing document files
which contain exclusively text without control characters are
ASCII files.
ASIC. Application specific integrated circuit.
ASSEMBLY LANGUAGE. Also known as machine code, the is a low
level, high efficiency language which provides rapid software
execution and results, but is somewhat difficult and
specialized. Basic or Cobol are high level languages. Assembly
is a low level language.
ASYNCHRONOUS. Serial type communications between computers such
that each bit at a time is individually transmitted. On an IBM
compatible computer, bits are sent in blocks of eight characters
made up of zeros and ones.
AUTOEXEC.BAT. This batch file runs automatically when you start
your computer. It is a text file containing a list of DOS
commands which you can customize with your word processor or
other editor to have the computer start a program, menu or other
software as you wish.
BAK FILES. Some software programs save older copies of data in
backup or BAK files. The extension is added to the file name so
that older data can be retrieved if necessary.
BASIC. Beginners All-Purpose Symbolic Instruction Code. A high
level programming language which usually is provided with DOS in
the file QBASIC, GWBASIC, or BASICA. Provides programming
capabilities which are relatively easy to learn and use.
BATCH FILE (or BAT file). A text file containing a list of DOS
commands to be carried out or executed. It is a small text program
which can be altered or created with your word processor or text
editor. Preparing and using batch files is itself a form of
programming and can greatly improve the efficiency and utility
of a computer. Tasks can be automated so the user does less
actual keyboard work.
BAUD. Bits per second. A speed measurement associated with modem
communications or data transfer between the computer and
printer, modem or another computer.
BENCHMARK. A software program or testing method which allows
similar computers or software programs to be compared.
BIDIRECTIONAL. Works in both directions. Frequently associated
with printers which print in both directions left to right then
immediately right to left. This saves printing time.
BINARY. Computer numbers represented by zeros and ones. It is
based on the number two. Only two numbers are used to represent
all possible values: the number 0 or 1. Binary is used by a
computer since the 0 and 1 are easily represented by transistor
switches which can have only two states: on or off.
BIOS. Basic Input and Output System. Software related to DOS
which controls input and output operations. The computer BIOS is
usually stored in an integrated circuit chip which can be
upgraded under certain circumstances.
BIT. A single binary digit. Represented electronically as a
digit one or zero inside a computer. In reality a bit is held
by a transistor switch inside an integrated circuit chip. If the
transistor switch is "on" the bit represented is one. If the
transistor switch is "off" the bit represented is zero. Bits
make up larger bytes.
BOOTING or BOOTING UP or BOOTSTRAP. Refers to initial starting
sequence which involves many software and hardware operations
such as loading DOS, checking memory, initializing printer, etc.
A reference to the computer "pulling itself up by the
bootstraps." A warm boot can be done by pressing together the
keys: CTRL, ALT and DEL. A cold boot is complete machine
shutdown followed by turning computer on again.
BUBBLE MEMORY. Specialized type of memory created by magnetizing
small regions of magnetic material within an integrated circuit.
This memory is nonvolatile and will not be lost when power is
removed. Relatively expensive and slow in performance and thus
not commonly used.
BUFFER. An area of memory used to hold data temporarily. Buffers
are used to hold files sent to the printer, data from the modem
or hard drive or other computer inputs and outputs. The
advantage of a buffer is that the computer is free to do
some other work while the buffer handles the data transfer.
BUG. A computer or software program error. To debug is to locate
and remove an error.
BULLETIN BOARD SYSTEM or BBS. A computer which can be accessed
with a modem and which contains capabilities to send and receive
message, send and receive software or exchange information.
BUNDLED SOFTWARE. Software sold with computer hardware as part
of the total purchase.
BUS. Circuits which connect devices together. The main electronic
path that data takes in a computer. Within the IBM PC the
original 62 pins and 8 slots were connected together in a bus or
interconnected arrangement which later became an industry
standard.
BYTE. For the IBM PC family of computers, a byte is an 8-bit
unit of memory which represents one character, for example the
letter E. Up to 256 different values are possible for a single
byte.
CACHE. A high speed area of RAM memory which holds data being
read to or from a disk drive or the CPU processor itself. This
saves time in that frequently used data does not have to be
repeatedly found on the slower disk drive compared to the speedy
CACHE in memory.
CD-ROM. Compact Disk, Read Only Memory. A type of data storage
on disk that uses a laser to read data. CD-ROM disks look quite
similar to standard music CD's. Data can be read from a CD-ROM
but not written to it, in most cases. Newer forms of CD-ROM are
available which allow writing to the disk also, but are quite
expensive.
CELL. A single box in a spreadsheet used for data entry.
CHARACTER. Letter, number or 8 bit item of computer data.
CHIP. Integrated circuit consisting of silicon or other rare
earth material which has thousands or millions of semiconductors
etched into a tiny area.
CISC. Complex Instruction Set Computer. A different method of
computing compared to RISC or reduced instruction set computing.
Many instructions are required to accomplish a given operation
on a CISC machine compared to a RISC machine which is an newer
emerging technology using inherently higher speed processor
chips with fewer internal instructions. The IBM PC and clones
use older CISC technology.
CLOCK/CALENDAR. An computer circuit which keeps the correct time
and date. Many computers contain this circuit as standard
equipment. Software programs access the clock/calendar device to
date and timestamp your files and provide other "date and time
sensitive" operations.
CLOCK SPEED. The timing frequency that a computer uses to
regulate and synchronize the timing of its operations. Usually
this timing speed is measured in Megahertz or millions of cycles
per second. For example one might say that a computer operates
at 12MHz (million cycles or operations per second). Extremely
high speed desktop computers can today operate at 66MHz and 100
MHz is on the horizon.
CLONE. An IBM compatible computer.
CLUSTER. Two or more sectors on a circular disk track. Each track
is usually divided into two clusters.
COMMAND LINE. The DOS command line where you type in a DOS
command to cause work to be done. Example: C>Diskcopy a: b:
is a command line which will perform a computer task.
COMPOSITE VIDEO. All colors of a single computer monitor are
combined in a single electrical input line. An inexpensive
manufacturing method which produces fair resolution at a reduced
price.
CONFIG.SYS. A small text file which is used by DOS when the
computer first starts. This file can be edited and changed as
necessary. This file informs DOS of the hardware and other
capabilities within the computer. CONFIG.SYS can also be
modified to control memory use within the computer. Device
drivers are frequently listed in the CONFIG.SYS file.
CONSOLE. A reference to a computer. Console within the DOS
software CONSOLE is often referred to as CON and various
commands are given such as COPY CON PRN or COPY CON FILENAME.
Console in this sense means the keyboard.
CONVENTIONAL MEMORY. The first 640K of RAM memory. Sometimes
called DOS memory.
CONTROL KEY. See CTRL key.
COPROCESSOR A specialized integrated circuit which assists the
main processor with math intensive operations and can speed some
software packages.
CPS. Cycles per second or characters per second.
CPU. Central processing unit. The primary integrated circuit
chip which controls computer operations. From earliest to most
modern some CPU chips are: 8088, 80286, 80386, 80486, Pentium.
These chips were originally designed by the Intel Corporation
but have since been copied or cloned by other manufacturers.
CTRL KEY. The key labeled Ctrl at the left of your keyboard.
This key is often used by holding down Ctrl and hitting another
key. Also called control key.
CURRENT DRIVE. The disk drive the computer is using at the
moment. The display prompt C> tells you that the C: hard drive
is the current drive. Usually the A: and B: drives are the first
two floppy drives. C: and D: are usually hard drives.
CURSOR. The flashing bright square your screen which shows where
information will appear when you press a key. The cursor
indicates the computer is waiting for input or information.
CYLINDER. A set of disk tracks at a specific location of a hard
drive platter or set of platters which can be read or written
simultaneously by the read/write heads. Conceptually, a cylinder
looks something like an empty tin can with the top and bottom
removed.
DAISY WHEEL. A printer with a spinning typewriter wheel which
spells out letters and characters. An early design printer.
DATABASE. An organized collection of records or information
which can be sorted, stored, searched, retrieved and reported
upon. A database consists of records and within each record are
fields containing, for example, the name, address and telephone
number of a person. A record is a collection of related data
items called fields.
DATA BUS. An electronic pathway which carries pulses of
electricity to and from the various integrated circuits and
components inside a computer. Usually a data bus consists of
between 8 and 32 conductive wires or lines, each capable of
delivering the bits and bytes which make up computer data.
Generally the more lines which make up the bus, the faster the
data can travel. Older computers use 8 bit data buses. Newer
PC's use 16 bit busses which can move data more rapidly.
DEFAULT. A standard computer setting when nothing otherwise is
specified. Can be changed in many programs temporarily or
permanently. If you are not sure of a setting in a program, it
may supply a default value automatically. For example a
spreadsheet might "default" to blue background with white
letters. This default could be changed by instructions to the
software program.
DESKTOP PUBLISHING. Using a desktop or portable computer to
generate typeset quality text and graphics. Frequently a laser
printer, special desktop publishing software and computer are
combined to produce the final printed result.
DEVICE DRIVER. A small software program loaded by CONFIG.SYS when
the computer is first started. A mouse, for example, uses a
device driver so that the computer can activate the mouse. A
device driver is a type of "software link" to a piece of
equipment or system within the computer. A CD-ROM also uses a
device driver.
DIALOG BOX. A small box on the monitor screen found in graphical
user software programs that provides information or allows for
selections or specific options.
DIP. Dual inline pins. A type of integrated circuit chip having
small pins extending in rows from either side of a plastic or
ceramic chip package.
DIRECTORY. An imaginary storage space on your disk which
contains files. This is similar to a table of contents in a
book.
DIRECTORY TREE. A method for organizing data into a heirarchal
structure with a main root directory at the top of the data
structure and subdirectories below it. A directory tree can be
diagrammed visually and is similar to a tree trunk with roots
branching below it downwards and outwards.
DISKETTE, DISK. A flat, usually flexible circular plastic plate
covered with magnetic coatings which can be used to store
information. Somewhat like tape recorder tape, but circular in
shape. Diskettes come in high and low density and both 3.5 inch
and 5.25 inch sizes.
DISK CONTROLLER. A circuit board which provides primary control
for hard or floppy disks.
DMA. Direct memory access. Refers to some devices in the computer
such as drives or memory which can transmit and receive data
without using the CPU. This speeds software and data operations.
DOCUMENTATION. Printed instructions or manuals.
DOS. Disk Operating System. DOS allows you to input information
from the keyboard to the computer, run programs, prepare files
for disks and other necessary tasks. DOS translates users
commands at a low hardware level and makes the commands
available to higher level applications such as spreadsheets,
games or word processors. DOS supplies a file management system
for efficient storage of data on disk for processing and safe
storage when the computer is off.
DOS EXTENDER. A special software extension or modification to a
software package which allows it to use more than the normally
allowed 640K bytes of memory. Allows use of extended memory.
DOS PROMPT. The small character that signals that DOS is
awaiting a command. A DOS prompt usually shows the current
drive. Here is an example of a DOS prompt: C>
DOT MATRIX. Type of printer which uses tiny pins or wires to
strike a ribbon and paper to produce images or characters. Older
printers were 9 pin. Newer, high resolution printers use 24
pins.
DRIVE A. The first floppy drive.
DRIVE B. The second floppy drive.
DRIVE C. Usually this is a hard drive.
DRIVER. Software program which allows DOS to work with a
specific hardware item such as a printer, mouse, trackball.
DUPLEX. Communications between computers which features data
transmission in both directions. Full duplex provides
simultaneous transmission in both directions. Half duplex allows
transmission in both directions, but never at the same time.
E-MAIL. Electronic Mail. Sending and receiving messages via
computers which link two or more users together. Messages are
stored and retrieved as needed by individuals in the network and
can be transmitting vast distances using ordinary telephone
lines or other wiring. Not necessarily FAX messages, although
these can be incorporated in into an E-Mail network in addition
to voice, photos, illustrations and text.
EEPROM. Integrated circuit memory chip. Electrically erasable
read only memory.
EGA. Enhanced graphics adapter. High resolution color circuit for
monitor display.
EISA. Extended Industry Standards Association.
EMS. Expanded memory specification. Standard for using additional
memory with IBM compatible computers. Memory is above the normal
640K. See also expanded memory is this glossary.
EPROM. Erasable Programmable read only memory integrated circuit
chip.
ESDI. Enhanced small disk interface. A hard drive specification
which allows high speed data transfer. Rates of up to 10
megabits per second are possible.
ENTER KEY. The large key to the right of your keyboard. On
many computers, this is labeled also labelled the Return key.
ESC KEY. The key on your computer labeled Esc, meaning Escape.
This key allows you to abort many computer entries and
operations.
EXPANDED MEMORY. Computer RAM memory which can be accessed only
through a "window" or "page frame" set up inside the first 1
Megabyte of RAM. The usual limit of expanded memory is 32MB.
Segments of this memory are quickly "paged in and out" of the
memory window to create an illusion to the central processing
chip of a large amount of memory. Something like flipping the
pages of a cartoon book to animate a story. Many applications
such as spreadsheets and databases can use this memory to handle
large tasks. Expanded memory is also called EMS memory.
EXPANSION CARD. Circuit card or circuit board which fits into
empty slots on the main circuit board inside the computer. Adds
capabilities such as video, FAX, modem, sound, parallel or
serial port.
EXPANSION SLOT. A socket inside the computer into which an
expansion card is inserted.
EXTENDED MEMORY. RAM memory which extends from the normal 1MB
DOS limit to the top address limit of the CPU. Using special
software it is possible to convert extended memory to expanded
memory. Extended memory is useful for software tasks like RAM
disks, print buffers and other applications. Many software
applications such as databases and spreadsheets can use extended
memory when needed for large tasks. Extended memory is also
called XMS memory.
EXTENSION. The last part of a filename, preceded by a dot which
frequently shows the file type. In the filename MYFILE.TXT the
extension is TXT. As an aside, TXT is usually a text file. A
file extension ending in TMP might mean a temporary file. A file
extension ending in WKS refers to a Lotus 123 spreadsheet file.
EXTERNAL COMMANDS. DOS commands such as FORMAT (and others)
which are retained only on disk and are temporarily loaded into
ram for use then disappear from ram after a task is complete.
They must be available on disk whenever used and are not
normally stored in memory.
FAT. File allocation table. A special area on a disk drive which
keeps track of the parts of a file which may be scattered
across the disk. The FAT tells the drive head where to locate
the portions of data.
FAX BOARD. An internal expansion board which can be plugged into
the PC to allow sending and receiving of FAX documents. These
documents can be stored on disk and later printed on a printer
or discarded. FAX boards also allow sending and receiving of FAX
documents to several clients in a row and even calling at times
of reduced telephone rates such as the early morning hours - all
completely unattended.
FIELD. An area of the screen (frequently a database program)
where data or text is entered. A field is essentially a category
of information.
FILE. A collection of data on a disk or in memory which has been
grouped together. This can be the text of a document, numbers
and formulas in a spreadsheet, or codes to run a program or
application.
FIXED DISK. See hard drive.
FLOPPY OR FLOPPY DISK. A permanent magnetic storage medium for
retaining data when the computer is off. Similar to a tape
cassette. It stores data, can be erased and re-used and
modified. Floppy disks are inserted into a floppy disk drive.
FONT. Typefaces of a character. Size and shape of character can
change. These families of typefaces or fonts have name such as
Helvetica, Courier, etc
FORMAT. To prepare a blank disk to receive data. Formatting
involves testing the disk for possible errors and preparation of
a file allocation table.
FRAGMENTATION. The process which gradually allows files on disk
to become widely scattered - thus slowing file retrieval.
Defragmentation involves a software reconfiguration which brings
file piece together in contiguous proximity for rapid access and
is a routine maintenance item.
FUNCTION KEYS. The keys on a keyboard labeled F1 - F10 (or F1 -
F12 on some keyboards). F1 traditionally is the help key in most
program and provides instructions.
GAME PORT. A plug in port on the back of the computer which can
accommodate joysticks or other game playing input devices.
GIGABYTE. One billion bytes.
GLOBAL. A software instruction or adjustment which will affect
data or program parameters throughout an entire software
application, document or hardware device.
GUI. Graphical User Interface. Pronounced "gooey". In some
respects easier to use than a DOS interface. Frequently a mouse
is used to point and click through a data processing task. Point
and select from a list of tasks or data rather than typing from
a barren blank DOS command line.
HARD DISK, HARD DRIVE, WINCHESTER DRIVE. Permanent, non-
removable storage device within the computer.
HARDWARE. Any part of a computer you can touch such as the
keyboard, case, monitor. Software is invisible and cannot be
touched although it resides within hardware.
HAYES COMPATIBLE. Modems that comply with standard HAYES
instruction commands which are considered an industry standard.
ALso known as the AT command set which stands for "attention" in
a HAYES modem.
HEADS. A reference to the read/write heads of a floppy or hard
drive. They are small electromagnetic coils attached to an arm
which moves freely over the surface of the spinning platter or
disk. Electric pulses to these coils creative small fields of
magnetism on the spinning surface below the heads.
HEXADECIMAL. Numeric system using base 16. Most memory locations
in a computer are calculated and displayed in hexadecimal
notation due to memory design considerations.
HIDDEN FILES. Files which are present but have been temporarily
hidden using DOS commands. Cannot be seen on an ordinary
director listing or search.
HIGH LEVEL FORMATTING. Is a process performed to a hard disk
after low level formatting (see below). This high level format
creates the directory structure of the disk (or file allocation
table area) which DOS will later use.
HIGH LEVEL LANGUAGE. Computer programming language which is
relatively easy to learn and use. Examples: BASIC, COBOL,
PASCAL.
IC. Integrated circuit. Also known as chips.
ICON. A small visual or pictorial symbol used to represent a
software program, task or item of data. Used especially with GUI
or visual interfaces. A mouse frequently maneuvers a pointer to
an ICON which is then selected by clicking (depressing a button
on the mouse) when the mouse pointer is on the ICON.
IDE. Integrated drive electronics. The term is associated with
high performance hard disk drives which contain the central
drive controller built into the hard drive instead as a separate
controller card which was used by earlier hard drives. An IDE
hard drive is optimized for AT class computers using 286, 386 or
486 CPU (central processing unit). IDE drives are, in general,
fast and reliable.
INK JET. This is a reference to a type of printer which forms
characters and images by spraying tiny jets of ink on either
plain paper or specially coated paper stock.
INPUT DEVICE. Hardware used to enter or send information on a
computer. A mouse, keyboard, game joystick, or trackball are
input devices.
INTEGRATED SOFTWARE. A type of software package which frequently
combines several standard software applications into one entity.
Frequently an integrated package will contain a spreadsheet,
database, word processor and perhaps and modem or telephone
dialing program.
INTEGRATED CIRCUIT. See CHIP or IC.
INTERLEAVE FACTOR. The spacing of non-consecutive sectors around
the track of a hard disk. Usually this is given as a ratio.
Optimal interleave configures these non-consecutive sectors for
speedy data retrieval from the hard disk. Example: an interleave
of 1:1 is considered very fast in hard drive performance
characteristics.
INTERNAL COMMANDS. Commands of DOS which are loaded into RAM
memory and do not require the DOS disk to be present to
function. Examples: DIR, COPY, RD
INTERPRETER. Software program which translates high level
programming instructions into low level machine or assembly code
which the CPU can process. Example: DOS contains a Basic
interpreter which you can use to write your own programs. It is
a form of Microsoft QuickBasic. Interpreted programs usually
require that the interpreter (example, QBASIC.EXE) be present to
run the program compared to more advanced compiled programs
which DO NOT require that an interpreter be available for the
program to run.
KB, KILOBYTE or K. Refers to one thousand bytes. More precisely
this is 1024 bytes.
LAN. Local area network. Circuits to allow several or many
computers to talk to each other and share data. Of interest to
business and office computer users, but of only passing interest
to home and home/office users having only one machine.
LASER PRINTER. Type of printer that uses a rapidly scanning laser
beam to build characters on a rotating drum which in turns
transfers images to toner ink and paper.
LOW LEVEL FORMAT. A preliminary process which is usually given to
a hard drive to prepare it for accepting data. Low level
formatting establishes tracks and sectors on the disk so the
drive can accept data and locate it for later retrieval.
Normally this will destroy all previous data! Low level
formatting is usually given to a hard drive at the factory,
although end users may also wish to low level format a drive for
various performance reasons.
LQ. Letter quality printer.
MACRO. A sequence of keystrokes or commands that can be recorded
and played back to execute a program or task of data entry thus
saving you keystrokes. In telecommunications (modem) software,
macros are also referred to as scripts. Many programs such as
spreadsheets, databases and word processors have a macro
"language" which allows you to adapt the program to
automatically perform a sequence of tasks rapidly instead of
using tedious repetitive keystrokes. Using and preparing macros
is itself a form a programming.
MAINFRAME. Large or corporate computer as compared to a smaller
desktop computer.
MASS STORAGE. All disk-oriented forms of data storage such as
hard and floppy disks, optical disks and backup tape drives.
MEGABYTE, MB or MEG. One million characters or memory areas.
MEMORY. A storage area inside your computer. Usually within
individual integrated circuit chips. Data stored in memory
disappears when the power is turned off and must be stored on a
diskette or other non-volatile memory device. Also called RAM
(random access memory) or simply RAM. ROM (read only memory) is
another type of memory which is used when the computer starts
and is cannot be changed or rewritten. ROM is also stored in a
different type of integrated circuit than RAM memory.
MEMORY ADDRESSABILITY. The number of separate individual memory
locations in RAM with which the CPU is capable of communicating.
MEMORY MANAGEMENT. The process of selecting and controlling the
assignment, use and location of software within RAM memory.
Careful memory management can speed software and allow for
larger data processing tasks or the operation of several software
programs at the same time or via rapid switching.
MEMORY MANAGER. A type of software program that can increase the
amount of available useful RAM memory by making extended or
expanded memory available to primary software applications such
as your spreadsheet or word processor. Later versions of DOS
contain small memory management programs which can be installed
via adjustment of the CONFIG.SYS and AUTOEXEC.BAT files.
MEMORY CACHE. An area in RAM memory, usually about 8K to 128K in
size, which the CPU can use to store frequently accessed data
rather than going to a hard drive or floppy disk. This speeds up
operations.
MENU. Display of choices or options on a list. You can select
one of the menu options with a mouse or by typing a letter. Then
the menu will run the software program you have selected.
MFM. Modified frequency modulation. An early standard for hard
disk data storage and transfer.
MHZ. Megahertz or one million cycles per second. Derived from
the name of Rudolf Hertz, an early electrical researcher.
MICROPROCESSOR. See CPU.
MILITARY TIME. A numerical time designation featuring 24 hours
in a day. For example, 1300 hours means 1PM. 2400 hours is
midnight. Basically, add 12 to the number of hours if a PM time
is shown. Military time is the standard used by most computers
for clarity.
MODEM. Derived from MODulator DEModulator which allows computers
to transfer information over phone lines.
MODES. When referring to CPU chips there are three modes: real,
protected and virtual which address memory in various ways.
Early 8088 processors have only REAL mode. More sophisticated
80386 processors have all three modes which allows for greater
RAM memory access and more sophisticated software applications.
MOTHERBOARD. Usually this is the largest circuit board within
the computer case and it contains the RAM memory, central
processing unit and expansion slots into which other boards are
plugged.
MOUSE. Hand operated pointing and selection device which serves
as alternate input to the keyboard.
MPC. Multimedia PC. A special type of computer designation
developed by Tandy Corporation and Microsoft which describes
minimum standards for computers which can run multimedia
software which makes use of sound, animation and frequently also
CD-ROM disks. The MPC rainbow logo appears on computers
configured for this type of use, although other types of
computers can be made MPC-capable by adding the requisite
hardware.
MULTIMEDIA. Computer presentations or software which make use of
sound, extensive graphics, animation and video in a colorful
highly detailed manner.
MTBF. Mean time between failures. A measurement of relative
reliability related to components such as hard drives or other
devices.
MULTITASKING. A computer which can perform several operations at
the same time.
NLQ. Near letter quality printer.
NULL MODEM CABLE. Special electrical cable used to transfer data
between two computers.
ONLINE SERVICE/BBS/BULLETIN BOARD. Computers connected to
telephone lines which users can access by modem. Messages to
other users can be left and retrieved. Software can be sent
(uploaded) or retrieved (downloaded), databases can be searched
for information.
OPERATING SYSTEM. Another name for DOS. The essential "core"
software which itself runs other programs and talks to the
keyboard and printer. There are other operating systems besides
DOS. For example UNIX, OS/2, Windows, CPM.
OS/2. Operating system 2. A proposed update to the DOS operating
system.
PAGING. The ability of software and hardware to store a portion
or segment of software instructions on the hard disk and then
retrieve it a later time. This allows conservation of limited
RAM memory.
PARAMETER. Information sent to a program. Example: /p is the
parameter of the DOS command DIR/p. Parameters modify a software
command.
PARITY CHECK. An error detection method used to test RAM memory
chips and assure reliable data transfer.
PARKING THE HEADS. Refers to the process of running a software
program to cause the read/write heads of a hard disk mechanism
to move to a track area of the disk which is of low use or is a
designated safe zone. Somewhat like lifting the needle from a
phonograph record and placing it on the "needle rest." This
prevents the possibility that the heads will drop or otherwise
gouge into the soft magnetic surface of the platters below. The
heads are usually parked while the disk is spinning and once
parked the machine is turned off. Early MFM and RLL hard drives
are usually parked by issuing a software command prior to
shutdown. Modern IDE drives park themselves automatically when
turned off.
PARTITION. A subdivision which is created by the FDISK utility
of DOS. A partition can be used to subdivide a hard disk into
more than one logical drive (e.g., C: and D:) or run various
operating systems from the same disk such as DOS and Unix. It is
usually established after a preliminary high-level format
process.
PATH. A list of subdirectories where DOS searches for
information. In a way it is a map or "route" which DOS searches
for information. You can set this with the DOS PATH command. The
path command is usually set within the AUTOEXEC.BAT file
mentioned above. See the DOS path command for syntax.
PASSWORD. A word or phrase which must input at the keyboard
before a program or operation can begin.
PLATTER. The physical disk medium of a hard drive or floppy
system onto which data is recorded and read back. Usually a
platter refers to a hard drive disk which is aluminum and coated
with a metallic iron oxide.
POINTING DEVICE. Mice, trackballs, light pens and so on allow
input to the computer in addition to the more conventional
keyboard.
PRESENTATION GRAPHICS SOFTWARE. Programs which produce charts,
text or images for businesses presentations. The illustration or
chart is designed on the computer screen and then finally output
to a lecture slide, overhead transparency, printed sheet or even
computer screen image which will later be viewed.
PROMPT. See system prompt.
PROTECTED MODE. A unique feature of the 80286 (and later) Intel
CPU chip to access RAM memory beyond the 1MB limit as well as
manage and protect multiple software programs in memory.
PROTOCOL. Software standards and software programs which ensure
reliable data transfer without error loss.
RAM, RANDOM ACCESS MEMORY. Temporary memory in your computer
(random access memory). When you turn the computer off, all RAM
contents are lost until replaced from data stored on a disk. RAM
resides inside small integrated circuit chips.
REAL MODE. A unique feature of the 80286 (and later) Intel CPU
chip which allows simulation of the 1MB memory limit and
instructions of the older 8086 CPU which allows operation of
older software programs. This is an example of "downward" or
"backwards" compatibility.
REBOOT. Touch the Control (Ctrl), Alt (Alt) and Delete (Del)
keys all at the same time. This restarts your computer without
turning it off. This is also know as a "warm reboot" as compared
with a "cold reboot" which means complete shutdown with via the
on/off switch.
RECORD. A set of information elements in a database. For example
the data Mr. Smith including his address, income, telephone
number and occupation would together constitute a single record.
RELATIONAL DATABASE. A database software package which can
interrelate multiple databases (e.g., parking ticket database
AND policemen on the force AND parking meters which are out of
order - each of these databases is a separate file, but a
relational database can interrelate them and produce very
complex reports and find unique relationships.) Relational
databases often contain complex command languages, application
generators, query systems, specialized report writers, SQL
support and more.
RESIDENT COMMANDS. DOS commands such as COPY, TYPE, DIR, DEL
which are retained in RAM instead of disk. Also called internal
commands. They are available at all times when DOS is in
operation.
RESIDENT PROGRAM. Program(s) which are loaded into your computer
temporarily and remain available until the computer is turned
off. Resident programs are also known as TSR programs (terminate
and stay resident.) Resident programs are "popups" such as
calendars, calculators and other devices.
RGB. Red, green blue. Reference to type of monitor or display
system. RGB monitors on early computers were frequently
associated with the CGA or low resolution color display
standard.
RLL. Run length limited. Hard disk data storage and transfer
scheme. Provides fifty percent high data density storage than
older MFM system. RLL is itself a somewhat antiquated type of
hard drive, but still in use in many machines. IDE hard drives
are a more popular option today.
ROM. Read only memory chip. Memory is not lost when computer
turned off.
ROOT DIRECTORY OR ROOT. The main directory on a disk. You are
not in a lower subdirectory area (e.g., C:\doc\wp\files) but in
the main directory (e.g., C:\)
SCSI. Small computer systems interface. Frequently pronounced
"scuzzy." A hard drive scheme which allows multiple hard drives
to be attached and high data transfer rates.
SCANNER. A device which can convert a printed image such as a
photo or illustration to a digital image within the computer
memory. Some scanners use OCR (optical character recognition) to
scan text documents containing printed words and convert them to
text characters in the computer as if a person had typed the
document. These scanned documents or illustrations can then be
edited, transmitted or stored as desired.
SECTOR. The smallest unit of storage on a hard or floppy disk
consisting of 512 bytes - typically there are either 17 or 26
sectors per track on a hard drive.
SERIAL. Data is transmitted one bit at a time. In comparison,
parallel data transfer sends eight bits at a time.
SIG. A special interest group of a computer club. Perhaps a
general purpose computer club might contain a SIG for word
processing users. And perhaps another SIG for those interested
in databases.
SIMM. Single inline memory module. Type of integrated circuit.
Usually a type of plug in memory module which adds more RAM type
memory to a computer. Currently this is the most common
configuration for RAM memory on modern computers of the IBM
clone type.
SIP. Single inline pins. Usually a type of plug in memory module
which adds more RAM type memory to a computer.
SOFTWARE. Programs used to manage the operations and data
contained within a computer. A set or list of instructions a
computer uses to accomplish a data processing task.
SOURCE. When doing file or disk copies, refers to the originating
disk or file.
SPOOL or SPOOLER. Simultaneous peripheral operations on line. A
memory storage buffer which holds data which can be fed to
printer, modem or other device while main processor is used for
other applications.
SPREADSHEET. A software program which simulates an "electronic
grid" or sheet of accounting ledger paper and divides the
monitor screen into rows and columns into which data and
formulas can be input. Spreadsheets in some cases also contain
database and word processing functions and are quite flexible.
SUBDIRECTORY. A directory of files on a diskette or hard drive
which is located within or below a "parent directory". The root
directory, the highest directory, is never a subdirectory.
SYSTEM PROMPT. When you look at your monitor screen and see the
DOS display such as: A> or C> you are looking at a
system prompt. You must next give DOS a command to run a program
or perform a DOS operation.
TARGET. The file or disk to which data is sent. If you are
copying a file from a disk in the A: drive to the B: drive, then
the B: drive is the target drive and contains the target disk.
TELECOMMUNICATIONS. Transmitting via electronic means data or
information, usually over telephone lines. A modem is used for
this task. Data, sound, pictures, video and FAX are all
transmitted via telecommunications methods.
TRACTOR. Printer with sprocket feed which handles paper
perforated along the edges.
TRACK. Concentric rings or circles of data sectors on a disk
platter which contain data and mark position points for the
read/write heads.
TRACKBALL. Somewhat like an upside down mouse. A large ball is
cradled in a plastic holder. As the ball is turned or rotated a
pointer on the computer monitor moves. Switches next to the ball
allow items on screen to be selected.
TROJAN HORSE. Type of software which may contains hidden code
which will damage data.
TSR. See resident programs. TSR is an acronym for "terminate
and stay resident" and is a type of software program that can
remain in background and then "pop up" over a software package
for brief use. For example, a pop up TSR calculator.
TURBO. High speed computer setting which operates the CPU
at high clock speeds.
USER GROUP. Computer club.
VAPORWARE. Announced software product which has not yet shipped.
VGA. Video graphics array. A circuit, usually on a plug in card,
which provides high resolution video output to the monitor.
VIRUS. Software program which is self-replicating and can cause
loss or damage to data or other software programs.
VOLATILE. Memory which can be lost if power is turned off.
VIRTUAL 8086 MODE. A unique operating feature of the Intel 80386
CPU chip that can provide several DOS software programs with a
1MB section of RAM memory which each act like a "separate small
8086 computer" which is running in real mode.
WINDOWS. Software package from Microsoft Corporation which
provides ease of use featuring point and click menus and
screens. Also refers to capability of any software package to
open a small window on the screen over an existing software
package or to split the screen into subdivisions so that several
documents or data sets can be examined simultaneously.
XMS. Extended memory. See extended memory elsewhere in this
glossary.
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