COMMUNITY COLLEGE OF SOUTHERN NEVADA
Department
Of Computer Information Technology
(Mr.
Harden’s Sections)
STUDY
GUIDE I
A computer an electronic
device, operating under the control of instructions stored in its own memory,
can accept data according to specified rules, produce results, and store
results for future use. A computer
system employs IPOS capability (Input-Process-Output Storage).
Data is
collection of unprocessed items which can include text, numbers, images, audio,
and video.
Information conveys meaning and is useful to
one or people.
A computer contains many electric, electronic, and
mechanical components known as hardware.
Software is a set
of instructions that tells the computer what to do and how to do it.
Systems Software consists of the programs
that control or maintain the operations of the computer and its devices.
Applications Software consists
of programs that perform specific tasks for users.
A handheld computer is a computer small enough to fit in one hand while you operate it with another hand.
A PDA (personal digital assistant) is a handheld computer that provides personal organizer functions such as calendar, appointment book, address book, and notepad.
A personal computer is a computer that can perform all of its input, processing, output and storage activities by itself, and contains a processor, memory, and one or more input, output, and storage devices.
A notebook computer (also know as a Laptop computer) is a portable personal computer small enough to fit on to your lap.
A minicomputer (also know as a midrange server) are used by small businesses to support dozens of users, or more, at the same time.
A mainframe
computer is large, expensive, very powerful computer that can handle
hundreds or thousands of connected users simultaneously.
A supercomputer is the
fastest, most powerful computer, and the most expensive.
A bit is the smallest unit of data the computer can process, and
is represented by a “0” or a “1”.
A byte is eight (8) bits grouped together as a unit.
Memory is the electronic components that store instructions
waiting to be executed by the processor, and data needed by those instructions,
and the results of processed data.
A kilobyte is approximately one thousand bytes.
A megabyte is approximately
one million bytes.
A gigabyte is approximately one billion bytes.
A terabyte is approximately one trillion bytes.
RAM are volatile memory chips that can be read from or written to
by the processor and other devices.
ROM are Nonvolatile memory chips storing permanent data and instructions.
A peripheral [outside input/output] device connects to the system unit and is
controlled by the processor in the computer, and includes modems, printers,
scanners, keyboards, etc.
A bus allows various devices both inside and attached to the
system unit to communicate with each other, and transfers bits from input
devices to memory, from memory to the processor, from the processor to memory,
and from memory to output or storage devices.
The central processing unit (cpu) intreprets and carries out the basic instructions that operates the computer.
The control unit (CU) is the component of the processor that
directs and coordinates most of the operations of the computer, and interprets
each instruction issued by a program and then initiates the appropriate action
to carry out the instruction.
The arthimetic logic unit (ALU) is a component of the processor that performs arithmetic, comparisons, and logical operations.
Registers are small high-speed storage locations in a processor
that temporarily hold data and instructions, and are not part of memory or a
storage device.
The system clock is a small quartz crystal circuit that controls
the timing of all computer operations, and generates regular pulses, or ticks,
that set the operating pace of components of the system unit.
One pulse tick (or pulse) per second is a Hertz.
One thousand ticks (or pulses) per second is a kilohertz.
One million ticks (or pulses) per second is a megahertz.
One billion ticks (or pulses) per second is a gigahertz.
One trillion ticks (or pulses) per second is a terahertz.
One one-thousandth of a second (of access time) is a millisecond.
One one-millionth of a second (of access time) is a microsecond.
One one-billionth of a second (of access time) is a nanosecond.
One one-trillionth of a second (of access time) is a picosecond.
Input is any data or instructions entered into the memory of a computer.
An input device is any hardware component that allows users to enter data or instructions(programs, commands, and user responses) into the computer.
A Keyboard is a device that contains keys that users press to enter data into a computer.
A pointing device is an input device that allows a user to control a pointer on the screen.
A mouse is a pointing device that fits comfortably under the palm
of your hand.
A trackball is a stationary pointing device with a ball (about the size of a ping-pong ball) on its top.
A touch pad is a small, flat, rectangular pointing device that is sensitive to pressure and motion, and is often used on laptop computers.
A pointing stick is a pressure sensitive pointing device shaped like a pencil eraser that is positioned between keys on a keyboard, and is ofter used on laptop computers.
A joystick is a pointing device that is a vertical lever mounted on a base.
A touch screen is a touch sensitive display device.
A stylus and a digital pen look like an ink pen, but use pressure, instead of ink, to write test and draw lines.
A scanner is a light sensitive device that reads text and graphics and then translates the results into a form the computer can process.
Optical character recognition (OCR) is a technology that involves reading typewritten, computer printed, or hand-printed characters from ordinary documents and translating the images into a form the computer can process (such as text editing or word processing).
An OCR device includes a small optical scanner for reading characters and sophisticated software to analyze what is read.
A bar code reader (also called a bar code scanner) is an optical reader that uses laser beams to read bar code.
A light pen is a handheld input device that can detect the presence of light. To select objects on the screen, a user presses the light pen at the screen and then presses a button on the pen.
MICR (magnetic-ink character recognition) devices read text printed with magnetized ink.
An MICR reader converts MICR characters into a form the the computer can process. The banking industry almost exclusively uses MICR for check processing.
A terminal consists of a keyboard and monitor, and provides both input and output to the host computer. There are three basic categories of terminals, which are: dumb terminals, smart terminals, and special purpose terminals.
A dumb terminal has no processing power, thus, cannot function as an independent device.
A smart terminal has a processor, giving it the capability of performing some functions independent of the host computer. In recent years, personal computers have replaced most smart terminals.
A special purpose terminal performs specific tasks and contains features uniquely designed for use in a particular industry. Special purpose terminals include POS terminals, ATM’s, and smart displays.
A POS (point of sale) terminal is used by retail stores to record purchases, process debit or credit cards, and update inventory.
An automatic teller machine (ATM) is a self service banking machine that connect to a computer through a network.
A smart display is a thin desktop monitor that detached from the computer to function as a portable wireless touch screen, which can access the computer remotely.
Output is data that has been processed into a useful form.
An output device is any type of hardware component that conveys information to one or more people.
A display device (or display) is an output device that visually conveys text, graphics, and video information.
A monitor is a plastic or metal case that houses a display device as a separate peripheral.
A CRT monitor is a desktop display device that is similar to the standard television because it contains a large, sealed glass tube like a television picture tube that displays computer results.
A LCD monitor is a desktop display device that uses a flat panel screen for display rather than a television picture tube like screen, and produces sharp, flicker free images.
A gas plazma monitor is a display device that uses gas plasma technology, which substitutes a layer of gas for the liquid crystal material in an LCD monitor.
A printer is a device
that produces text and graphics on a physical media such as paper or
transparency film.
An impact printer forms characters and graphics on a piece of
paper by striking a mechanism against an inked ribbon that physically contacts
the paper.
A dot-matrix printer produces printed images when tiny wire pins on a print head mechanism strike an inked ribbon, which then presses against the paper, and creates dots that form characters and graphics.
A line printer is a high-speed impact printer that is measured by the number of lines per minute (lpm) that it can print.
A non-impact printer forms characters and graphics on a piece of paper without actually striking the paper.
An ink-jet printer forms characters and graphics by spraying tiny drops of liquid ink onto a piece of paper.
A laser printer is a high-speed, high-quality non-impact printer,
sometimes called a page printer, because it processes and stores the entire
page before actually printing it.
A thermal printer generates images by pushing electrically heated pins against heat sensitive paper.
A multifunction peripheral is a single device that looks like a copy machine but provides the functionality of a printer, scanner, copy machine, and perhaps a fax machine, and is sometimes called an “all-in-one device”.
The storage device is the computer hardware that records and/or retrieves items to and from storage media.
A floppy disc is a portable, inexpensive storage media that consists of a thin, circular, flexible plastic Mylar film with a magnetic coating enclosed in a square-shaped plastic shell.
A zip disk is a type of portable magnetic media that can store 100MB to 750MB of data.
A hard disk is a storage device that contains one or more inflexible, circular platters that store data, instructions, and information.
A CD-ROM (compact disc read-only memory) is a type of optical disc that uses laser technology to store data, instructions, and information. Users can read only the contents of these discs.
A CD-R (compact disc-recordable) is a CD onto which user can record their own items such as text, graphics, and audio. Each part of this CD can be written on only one time, and the disc’s contents cannot be erased.
A CD-RW (compact disc-rewritable) is a type of optical disc that is erasable and you can write on multiple times.
A DVD-ROM (digital versatile disc-ROM) is an extremely high capacity optical disc capable of storing 4.7 GB to 17 GB and is not recordable.
A DVD-R (digital versatile disc-recordable) is a DVD that allows users to write on the disc once and read (play) it many times.
A DVD-RW (digital versatile disc-rewritable) is a DVD that a user can erase and record more than 1,000 times.
A tape is storage media that is a magnetically coated ribbon of
plastic capable of storing large amounts of data and information at low cost.
A USB flash drive, sometimes called a keychain drive, is a flash memory storage device that plugs into a USB (universal serial bus) port on the computer or portable device.
The binary number 101 is the same quantity as the decimal value is 5 (1x4 + 0x2 + 1x1 = 5)
The sum of the two binary numbers 11 and 10 is the binary value is 101
1 1
+
1 0
-------
1 0 1
====
Have a good day!