Please enable JavaScript.
Coggle requires JavaScript to display documents.
CHAPTER 2: COMPUTER HARDWARE, android-grammarly On screen keyboard,…
CHAPTER 2: COMPUTER HARDWARE
Type of Computers
Servers and
terminals
A server is a computer dedicated to providing one or more services to other computers or devices on
SERVER
A mainframe is a large, expensive, powerful server that can handle hundreds or thousands of connected users simultaneously
supercomputers
A supercomputer is the fastest, most powerful
computer — and the most expensive
1 more item...
–Rack server
–Blade server
–Tower server
Game devices
A game console is a mobile computing device designed for single-player or multiplayer video games.
A handheld game device is a small mobile device that contains a screen, speakers, controls, and game console all in one unit.
Game controllers include gamepads, joysticks and wheels, dance pads, and a variety of motion-sensing controllers.
Embedded
computers
An embedded computer is a special-purpose computer that functions as a component in a larger product
Consumer
electronics
Home automation devices
Computer devices and office machines
Process controllers and robotics
Automobiles
summary
Characteristics of and purchasing guidelines for desktops, laptops, tablets,smartphone, digital cameras, and portable media players
Handheld computers, servers, supercomputers, point-of-sale terminals, ATMs, self-service kiosks, e-book readers, game devices, embedded computers, and cloud computing
Desktop and mobile
computers
A
Personal Computer (PC)
is a computer that can perform all of its input, processing, output, and storage activities by itself and is intended to be used by one person at a time.
A
Desktop, or Desktop Computer
, is a personal computer designed to be in a stationary location, where all of its components fit on or under a desk or table.
A
Laptop
, also called a notebook computer, is a thin, lightweight mobile computer with a screen in its lid and a keyboard in its base.
A
Tablet
is a thin, lightweight mobile computer
that has a touch screen.
Mobile computer is a portable personal computer, designed so that a user easily can carry it from place to place.
A
Handheld Computer
is a computer small enough
to fit in one hand
Smartphones, digital cameras, e-book readers and portable media players
A smartphone is an Internet-capable phone that usually also includes a calendar, an appointment book, an address book, a calculator, a notepad, games, browser, and numerous other apps
Many smartphones have touch screens. Instead of or in addition to a touch screen, some have a built-in mini keyboard on the front of the phone or a keyboard that slides in and out from behind the phone
• A digital camera is a mobile device that allows users to take photos and store the photographed images digitally
An e-book reader (short for electronic book reader), or e-reader, is a mobile device that is used primarily for reading e-books and other digital publications.
A portable media player, sometimes called a personal media player, is a mobile device on which you can store, organize, and play or view digital media
SUMMARIZE
Input Devices
Commonly used input methods
Touch screens
A touch screen is a touch-sensitive display
You use your thumb or finger to rotate or press buttons on a touch-sensitive pad, which commonly is found on portable
media players.
Pointing devices
small symbol on the screen whose location and shape change as a user moves a pointing device
mouse - touchpad - trackball
A mouse is a pointing device that fits under the palm of your hand comfortably
A touchpad is a small, flat, rectangular pointing device that is sensitive to pressure and motion
A trackball is a stationary pointing device with a ball
on its top or side
Keyboard
input device that contains keys you press to enter data and instruction into computer
Contain:
Typing area
Function keys
Toggle key
Navigation keys
Media control buttons
Internet control buttons
Other special keys
Built-in keyboard
Ergonomic keyboard
Ergonomics incorporates comfort, efficiency and safety in the design of workplace
Has a design that reduces the chance of repetitive strain injuries (RSIs) of wrist and hand.
Pen input
stylus or digital pen on a flat surface to write, draw and make selections
stylus - digital pen - graphics tablet
Motion input
users can guide on-screen elements using air gestures with motion input
game controller
Video input
Video input is the capturing full-motion images and storing them on a computer or mobile device’s storage medium
webcam - video conference
Voice input
process of entering input by speaking into a microphone
siri
Audio input is the process of entering any sound into the computer such as
speech, music, and sound effects
Definition
Input is any data and instructions entered into the
memory of a computer
System Unit
Computing Components
Memory
Memory consists of electronic components that store instructions waiting to be executed by the processor, data needed by those instructions, and the results of processing the data
It stores three basic categories of items:
The operating system of and programs
Data being processed and the resulting informations
Applications
Each bytes resides temporarily in a location in memory that has an address and memory sizes commonly is measured in gigabytes (GB)
Computers and mobile devices contain 2 types of memory
Volatile memory
Loses its contents when power is turned off. For example, RAM
Nonvolatile memory
Does not lose contents when power removed. For example, ROM, flash memory, CMOS
There are two types of common RAM
Dynamic RAM (DRAM)
Static RAM (SRAM)
Memory cache speeds the processes of the computer because it stores frequently used instructions and data Figure 6-14
Memory cache speeds the processes of the computer
because it stores frequently used instructions and data
Read-only memory (ROM) refers to memory chips storing permanent data and instructions such as Firmware
Flash memory can be erased electronically and rewritten
CMOS technology uses battery power to retain information when the power to the computer is off
Access time is the amount of time it takes the
processor to read from memory and measured in nanoseconds
Processors
The processor, also called the central processing unit (CPU),interprets and carries out the basic instructions that operate a computer
The control unit is the component of the processor that directs and coordinates most of the operations in the computer
The arithmetic logic unit (ALU), another component of the
processor, performs arithmetic, comparison, and other operations
For every instruction, a processor repeats a set of four
basic operations, which comprise a machine cycle
The processor contains registers, that temporarily hold data and
instructions
The system clock controls the timing of all computer operations
The leading manufacturers of personal computer
processor chips are Intel and AMD
A processor chip generates heat that could cause the chip to malfunction or fail
Inside The Case
Describe the various computer and mobile device
cases and the contents they protect
The motheroard is the main circuit board of the computer
A computer chip is a small piece of semiconducting material , usually silicon, on which integrated circuits are etched
Figure 6-3 A desktop motherboard and a laptop motherboard.
the Cloud
Home and business users choose cloud computing for a variety of reasons
Cost savings
Space savings
Accessibility
Scalability
Data Representation
Analog signals are continuous and vary in strength and quality
Digital signals are in one of two states: on or off
Most computer are digital
The binary system uses two unique digits (0 and 1) which is bits and bytes
Data Representation
Digital signals are in one of two states: on or off
Analog signals are continuous and vary in strength and quality
The Circuitry in a computer or mobile device represents the on or off states electronically by the presence or absence of an electrical charge.
.
Adapter
An adapter card enhances functions of a component of a desktop
or server system unit and/or provides connections to peripheral devices.
With Plug and Play technology, the computer
automatically can recognize peripheral devices as you install them.
A USB adapter enhances functions of a mobile
computer and/or provides connections to peripheral devices.
Power Supply and Batteries
The power supply or laptop AC adapter converts the wall outlet AC power into DC power
Mobile computers and devices can run using either a
power supply or batteries
Batteries typically are rechargeable lithium-ion batteries
Buses
A bus allows the various devices both inside and attached to the system
unit to communicate with one another
Figure 6-18 Just as vehicles travel on a highway, bits travel on a bus. Buses are used to transfer bits from input devices to memory, from memory to the processor, from the processor to memory, and from memory to output or storage devices.
A computer might have these three types of buses
Backside bus
Expansion bus
System bus
Storage devices
Storage
A
storage medium
is the physical material on which a computer keeps data, information, programs, and applications
Cloud storage
keeps information on servers on the Internet,and
the actual media on which the files are stored are transparent to
the user
A
storage device
is the hardware that records
and/or retrieves items to and from storage media
Reading
is the process of transferring items from a storage medium into a memory
Writing
is the process of transferring items from a memory to a storage medium
Capacity
is the number of bytes a storage medium can hold
An Illustration of Volatility
Screen Display Volatile
Contents of Most RAM Volatile
Contents of Storage Nonvolatile
Access time
measures:
The time required to deliver an item from memory to the processor
The amount of time it takes a storage device to locate an item on a storage medium
Memory
is
faster
than
storage
but is
expensive
and
not practical
for all storage requirements. Storage is
less expensive
but is
slower
than memory
Hard drives
A hard disk also called a hard disk drive (HDD) contains one or more flexible circular patterns that use magnetic particles to store data, instructions and infomation.
The hard disk in a personal computer is enclosed inside an airtight, sealed case. The laptop hard disk is much smaller than the desktop hard disk
The storage capacity of hard disks is determined by
The number of platters the hard disk contains
The composition of the magnetic coating on the platters
Whether the disk uses longitudinal or perpendicular
recording
Density
Formatting is the process of dividing the disk into
tracks and sectors
Tracks form circles on the surface of a hard disk. The The
disk’s storage locations are divided into wedge-shaped sections, which break the tracks into small arcs called sectors. Several
sectors form a cluster.
Characteristics of a hard disk include:
Tracks
sectors
platters
form factor
read/ write head
revolutions per minute
A head crash occurs when a read/write head
touches the surface of a platter
SSD (solid state drive) is a flash memory storage device that
contains its own processor to manage its storage
An SSD (solid state drive) has several advantages over traditional
(magnetic) hard disks
faster access time
faster transfer rates
quieter operation
more durable
lighter weight
less power consumption
less heat generation
longer life
defragmentation not required
external hard drives
separate freestanding storage device that connect with a cable to a USB
port or other port on a computer or mobile device
RAID (redundant array of independent disks) is a
group of two or more integrated hard drives
Portable flash memory storage
A memory card is a removable flash memory storage device that you insert and remove from a slot in a computer, mobile device, card reader/writer
-
SDHC, SDXC, miniSD, microSDHC
microSDXC, CF, xD Picture Card, Memory Stick PRO Duo, M2
Optical dics
Consists of a flat, round, portable disc made of metal, plastic, and lacquer that is written and read by a laser.
How a Laser Reads Data on an Optical Disc
- This figure shows how a laser reads data on an optical disc.
Optical discs commonly store items in a single track that spirals from the center of the disc to the edge of the disc.
Track is divided into evenly sized sectors.
- An optical disc typically stores, data, instructions, and information in a single track that spirals from the center of the disc to the edge of the disc.
A
CD-ROM
can be read from but not written to - Single-session disc.
A
CD-R
is an optical disc on which users can write once, but not erase.
A
CD-RW
is a multisession disc.
A DVD-ROM is a high-capacity optical disc on which users can read but not write on or erase.
A DVD-R or DVD+R are competing DVD-recordable WORM formats, on which users can write once but not erase.
DVD-RW, DVD+RW, and DVD+RAM are competing DVD-rewritable formats that users can write on multiple times.
Enterprise storage
- An example of how network attached storage connects on a network.
Enterprise hardware allows large organizations to manage and store data and information using devices intended for heavy use, maximum efficiency, and maximum availability. - RAID duplicates data, instructions, and information to improve data reliability.
- A storage area network provides centralized storage for servers and networks.
A storage area network (SAN) is a high-speed
network with the sole purpose of providing
storage to other attached servers
Tape is a magnetically coated ribbon of plastic capable of storing large amounts of data and information
A tape drive reads and writes data and information on a magnetic tape
- In RAID level 1, called mirroring, a backup disk exists for each drive. Other RAID levels use striping; that is; portions of each drive are placed on multiple drives.
Network attached storage (NAS) = a server that is placed on a network with the sole purpose of providing storage to users, computers, and devices attached to the network.
A tape robot retrieves tape cartridges.
Other types of storage
magnetic strip card
smart card
RFID tag
NFC chip
Output Devices
PRINTERS
,
• A printer is an output device that produces text and graphics on a physical medium
• Before purchasing a printer, ask yourself a series of questions
,
• A nonimpact printer forms characters and graphics on a piece of paper
without actually contacting the paper
– Ink-jet printers
– Photo printers
– Laser printers
– All-in-one printers
– 3-D printers
– Thermal printers
– Mobile printers
– Label printers
– Plotters
– Large-format printers
,
• An ink-jet printer forms characters and graphics by spraying tiny drops of liquid ink onto a piece of paper
– Color or black-and-white
– Speed is measured by the number of pages per minute (ppm) it can print
,
• A photo printer is a color printer that produces lab-quality photos
– Many use ink-jet technology
• An all-in-one printer is a single device that prints,
scans, copies, and in some cases, faxes
– Also called a multifunction printer
,
A 3-D printer uses a process called additive
manufacturing to create an object by adding material
to a three-dimensional object, one horizontal layer at a
time
,
A thermal printer generates images by pushing
electrically heated pins against the heat-sensitive
paper
,
A mobile printer is a small, lightweight, battery-
powered printer that allows a mobile user to print from
a mobile device
,
A label printer is a small printer that prints on an
adhesive-type material that can be placed on a variety
of items
,
• Plotters are used to produce high-quality drawings
• Large-format printers create photo-realistic quality color prints
,,
impact printers form characters and graphics on a
piece of paper by striking a mechanism against an
inked ribbon that physically contacts the paper
,
DISPLAYS
• The quality of a display depends primarily on its:
– Resolution
– Response time
– Brightness
– Dot pitch
– Contrast ratio
-Today’s monitors use a digital signal to produce a picture
• To display the highest quality images, the monitor should plug in a:
– A DVI cable
– An HDMI cable
– A Display cable
• Home users sometimes use a digital television (DTV) as a display
• HDTV is the most advanced form of digital television
• A Smart TV is an Internet-enabled HDTV
,
Smart TVs enable you to connect to the Internet
and/or watch television shows.
,
TYPES OF OUTPUT DEVICES
-Monitor Display
Laptop Display
Camera Display
GPS Display
Handheld Console Display
Smartphone Display
– LCD monitor
• A monitor is a display that is packaged as a separate peripheral device
• A display visually conveys text, graphics, and video information
Output is data that has been processed into a useful form
Other Output Devices
.
Many users attach surround sound speakers or speaker systems to their computers, game consoles, and mobile devices to generate higher-quality
sounds🤙🏻
,
• Headphones 🎧 are speakers that cover or are placed outside of the ear
• Earbuds (also called earphones) rest inside the ear canal👂🏻
,
• A data projector is a device that projects the text
and images displaying on a computer or mobile
device screen on a larger screen so that an audience
can see the image clearly
,
• An interactive whiteboard is a touch-sensitive
device, resembling a dry-erase board, that displays
the image on a connected computer screen
,
• Joysticks, wheels, gamepads, and motion-sensing game controllers can be considered output devices when they include force feedback
– Technology that sends resistance to the device in response to actions of the user
Gaming devices often use force feedback, giving the user a realistic experience.
Assistive Technology Input and Output
,
A camera/receiver mounted on the monitor tracks the position
of the head-mounted pointer, which is the reflective material on the brim of
the hat. As the user moves her head, the pointer on the screen also moves
A Braille printer.
Summary
• Variety of options for input and output
• Several assistive technology options for input and output
On screen keyboard
Clip-on keyboard
• A terminal is a computer, usually with limited processing power, that enables users to send data to and/or receive information from a server, or host computer
• A thin client is a terminal that looks like a desktop but has limited capabilities and components
• Most retail stores use a POS terminal to record purchases, process credit or debit cards, and update inventory
