Transcript CHAPTER 2: Hardware and Software

CHAPTER 2:
Hardware and Software
Presented by:
Arlene N. Baratang
HARDWARE
Computer Hardware
• Computer hardware refers to
the various electronic
components that are required
for you to use a computer
along with the hardware
components inside the
computer case.
Hardware
Components
Communication Device
• Communication devices
translate one form of
communication from an internal
or external input device into
which the computer can
understand, then sending to an
output device, or to another
computer.
Input Device
• Input devices, or tools, are
used for entering information
into the computer.
Output Device
• Output devices are peripheral
devices that convert machinereadable information into
people-readable form such as a
monitor, printer, plotter and
voice output device.
Secondary Storage
• Secondary storage is also
called auxiliary storage, and is
used to store data and
programs when they are not
being processed.
Processing Devices:
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Control Unit
Arithmetic and Logic Unit (ALU)
RAM
Registers
Main memory
Cache memory
Processing
Characteristics &
Functions
Machine Cycle Time
• Machine cycle time, or access
time, is the time the CPU
executes an instruction
measured in nanoseconds.
Machine cycle time is one
measure of processing speed.
Clock Speed
• Clock speed refers to the
number of electronic pulses the
CPU produces at a
predetermined rate, which
affects the machine cycle time.
Word Length
• Word length is simply a fixedsized group of bits that are
handled together by the
machine. It usually has a word
size of 16, 32, or 64 bits.
Memory
Characteristics and
Functions
Storage Capacity
• Storage capacity is measured
in kilobytes, megabytes, or
gigabytes. The term “storage
capacity” is used to describe
disk drives with storage media
such as floppy disks, highcapacity Zip disks, CD-ROMs,
and tape cartridges.
Types of Memory
RAM
• Random Access Memory (RAM) has
two memory devices, static RAM, or
SRAM, and dynamic RAM, or DRAM.
SRAM retains its contents while
power is on but unleashed when off.
DRAM has an extremely short data
lifetime, like four milliseconds even
power is applied constantly.
ROM
• Read-Only Memory (ROM) has
the ability to retain data and
programs even during power
failure, and it provides
permanent storage for
instructions such as programs
the computer manufacturer.
Programmable ROM
• Programmable ROM (PROM) is
purchased in an
unprogrammed state. The data
of an unprogrammed PROM is
made up entirely of 1's.
Erasable-andProgrammable ROM
• Erasable-and-Programmable
ROM (EPROM) is programmed
exactly like PROM. However,
EPROMs can be erased and
reprogrammed repeatedly.
Hybrid Memories
• Hybrid memories can be read
and written like RAM, but
maintain its contents without
electrical power, like ROM.
Electrically-Erasableand-Programmable ROM
• Electrically-Erasable-andProgrammable ROM (EEPROM)
are similar to EPROMs, but the
erase operation is
accomplished electrically,
rather than by exposure to
ultraviolet light.
Flash Memory
• Flash memory devices are high
density, low cost, nonvolatile,
fast (to read, but not to write),
and electrically reprogrammable.
Non-volatile RAM
• Non-volatile RAM (NVRAM) is
like an SRAM with a battery
backup. NVRAM operates when
the power is turned on, just like
any other SRAM.
Multiprocessing
Parallel Processing
• Parallel processing is the
simultaneous use of more than one
CPU to execute a program. Parallel
processing is also by connecting
the single-CPU computers in a
network, however, this type of
processing requires very
sophisticated software called
distributed processing software.
Grid Computing
• Grid computing is a form of
networking. Grid computing
harnesses unused processing
cycles of all computers in a
network for solving problems.
Secondary Storage
Devices
Magnetic Tapes
• Magnetic tapes are
magnetically coated strip of
plastic on which data can be
encoded. Tapes are sequentialaccess media, which means
that the tape must go through
all the preceding points.
Magnetic Disk
• Magnetic disk is a round plate
on which data can be encoded.
There are two basic types of
disks: magnetic disks and
optical disks.
Different Forms of Magnetic
Disks:
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Floppy disk
Hard disk
Removable cartridges
Optical disk
Redundant Array of
Independent/Inexpensive Disks
(RAID)
Different Forms of Magnetic
Disks:
• Storage Area Network (SAN)
• Memory card, or flash memory
card
• Memory stick
• Universal serial bus (USB) flash
drives
• MultiMediaCard (MMC)
• Secure Digital Card (SD card)
Different forms of
optical disks:
• Compact Disc-Read-Only
Memory (CD-ROM)
• CD-ReWritable (CD-RW)
• Digital Versatile Disk (DVD)
Input Devices
Input Devices:
• Personal computer input
devices
• Mouse
– Mechanical mouse
– Optical mouse
– Serial mouse
– USB mouse
– Cordless mouse
Input Devices:
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Voice recognition devices
Terminals
Touch-sensitive screens
Bar-code scanners
Optical data readers
Point-of-sale (POS) devices
Automatic teller machine (ATM)
Input Devices:
• Magnetic ink character
recognition (MICR)
• Radio frequency identification
(RFID)
Output Devices
Output Devices:
• Visual Display Units (VDU)
Features of a Visual Display Unit
– Size
– Resolution
– Refresh Rate
– Type
– Color
– Scan Pattern
Output Devices:
• Printers
Types of Printer:
– Impact printer
– Non-impact printer
• Plotters
Types of Plotter:
– Pen plotters
– Electrostatic plotters
Computer
Systems
Types of Computer
Systems:
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Palmtops or PDA
Laptops or notebooks
Thin Client
Workstation
Server
Mainframe computers
Supercomputers
Grid Computing
• Grid computing is a form of
networking. Grid computing
harnesses unused processing
cycles of all computers in a
network for solving problems.
Grid Computing
• Grid computing is a form of
networking. Grid computing
harnesses unused processing
cycles of all computers in a
network for solving problems.
SOFTWARE
System Software
• Operating System (OS)
Functions of OS:
– Common computer hardware
functions
– Providing a user interface
– Providing a hardware
independence
– Managing system memory
System Software
• Operating System (OS)
Functions of OS:
– Providing networking capability
– Controlling access to system
resources
– Managing files
System Software
• User interface
– Command-based user interface
– Graphical user interface (GUI)
– Application program interface
(API)
Current OS
• Windows XP
• Apple Computer Operating
System
• Linux Operating System
• Palm OS
Application Software
• Proprietary Application
Software
– Off-the-Shelf Application
Software
– Customized Package
Application Software
• Personal Application Software
– Word Processing
– Spreadsheet Application
– Database Application
– Graphics Program
– Software Suites
Application Software
• Workgroup Application
Software
• Enterprise Application Software
Programming
Languages
• Programming languages are
sets of symbols and rules used
to write program code for
system and application
software.
Evolution of Programming
Languages
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First-Generation Languages
Second-Generation Languages
Third-Generation Languages
Fourth-Generation Languages
Fifth-Generation Languages
Software Issues and
Trends
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Software Bugs
Open sourcing
Software Licensing
Global Software Support