Transcript Elements of Computer

3 FUNDAMENTAL
ELEMENTS OF A
COMPUTER
• System Unit
• Output Devices
• Input Devices
• The system unit acts like the center or
core, processing the data and
information it receives from input
devices.
• Output devices like printers receive
the system unit’s processed
information
SYSTEM UNIT
• The system unit the core of a
computer is responsible for
processing and storing data and
controls all computer functions
• It is in the system unit that raw data is
processed into information.
• The system unit works with the
computer’s peripheral devices.
The System case
• The system case is a plastic and
metal box that houses components
such as the motherboard, disk drives
and power supply unit.
System Case Types
• There are two basic types of system
case: desktop and tower.
• Desktop case: is designed to sit
horizontally on a surface, so that it is
wider than it is long. These are
usually used for office or home PCs.
2 basic sizes: standard and slimline.
• Tower case: is designed to sit
vertically on a surface, so that it is
higher than it is wide. 3 basic sizes:
full, midi and mini.
• Full-tower cases: are usually used for
PC servers.
• Midi-tower cases: are used for higherend user PCs.
• Mini-tower cases: are usually for
office or home PCs.
Parts of the Case
• Cover: the case has a cover which is removed
by either undoing the screws at the back, or
pressing together clips that release it.
• Front Panel: provides access to the floppy and
CD, a power on/off switch, a reset switch, and
LEDs (light Emitting Diodes) to indicate drive
operation.
Parts of front panel cover: CD-R and CD-RW
drives, removable hard disk, 3.5 floppy disk,3.5
drive bays, LEDs, Reset switch, Power on/off
switch.
• Rear Panel: the rear has slots
through which interface card
connectors appear.
1. Power Supply Unit
2. Motherboard I/O ports
3. Expansion card I/O ports
THE MOTHERBOARD
• The motherboard is the largest board of
the computer system.
• The motherboard contains the CPU, BIOS,
memory, mass storage interfaces, serial
and all the controllers required to control
standard peripheral devices, such as the
display screen, keyboard, and disk drive.
• Chipset: chips that reside on the
motherboard.
BASIC PARTS OF INTEL
MOTHERBOARD
• The mother board battery: is used to
preserve the computer’s clock’s time
and your BIOS settings while the
computer is turned off.
THE CENTRAL PROCESSING
UNIT-CPU
• Is the device that interprets and executes
instructions.
• Today’s single-chip central processing units,
called microprocessors, make personal
computers and workstations possible.
• It has the ability to fetch, decode, and execute
instructions and transfer information to and from
other resources over the computer’s main datatransfer path, the bus.
• It functions as the brain of a computer
CLOCK
• The system clock synchronizes the
operation of all parts of the PC.
• It consists of a clock generator that
sets up a timing signal, and clock
multipliers.
MEMORY
• 2 fundamental types:
– main memory and
– secondary memory
MAIN MEMORY
• Very closely connected to the
processor.
• The contents are quickly and easily
changed.
• Holds the programs and data that the
processor is actively working with.
• Interacts with the processor millions
of times per second.
• Most computers available today have
memory capacities of 64Mb to 256Mb.
• When programs and data become active,
they are copied from secondary memory
into main memory where the processor
can interact with them.
• Main memory sometimes called: RAM
• RAM (Random Access Memory), radom
means that the memory cells can be
accessed in any order.
RANDOM ACCESS MEMORY
(RAM)
• It means the computer can store,
retrieve, alter or delete any items held
in the RAM’s at random.
• It is a semiconductor-based memory
that can read and written.
• Main memory is build from small
circuit boards called MEMORY
MODULES.
• Still the current standard in system
memory, usually of SDRAM (synchronous
RAM) type.
• DIMM chips are usually distributed in
64MB, 128MB or 256 MB on a single chip.
• DIMMs (dual inline memory module) have
two access pathways, they do not need to
be fitted in pairs as they can be written to
and read at the same time
ROM BIOS
• The BIOS (basic input output system) is a ROM
(read only memory) chips that provides:
– The industry standard program code that operates the
fundamental components of the PC (for example,
VDU, keyboard, printer port) and ensures that the
design of each manufacturer’s motherboard is PCcompatible.
– The routines that allow the setup configuration of a
PC (stored in the CMOS RAM) to be viewed and
edited.
– The power-on self-test (POST) diagnostic tests for the
PC
• BIOS chip cannot be swapped
between different motherboards.
• The BIOS is often known as firmware
as it consists of both the physical chip
(hardware) and the programs coded
into it (software).
• The ROM BIOS is normally a DIP
chip that can be identified by a label
on the chip.
CMOS RAM
• CMOS RAM stores the configuration
of the PC.
• CMOS stands for Complimentary
Metal-Oxide Semiconductors, which
describes the manufacturing process
used to make RAM chip.
• The CMOS battery is either a NICard,
lithium or alkaline cell
SECONDARY MEMORY
• Connected to main memory through the
bus and a controller
• The contents are easily changed, but this
is very slow compared to main memory
• Used for long-term storage of programs
and data
• The processor only occasionally interacts
with secondary memory
• Common secondary storage devices are
the floppy disk and hard disks and
compact disks or CD
• It is a thin and flimsy as a sheet of paper
but is protected by the sturdy, square
jacket that encases it.
• Since the rust is made of iron, which can
be magnetized, the disks stores magnetic
signals.
• The pattern of magnetic signals is a code
representing your data
• 3 Standard sizes:
– 8-inch is called a largefloppy
– 5.25-inch is called a minifloppy
– 3.5-inch is called a microfloppy
•5.25-inch floppies were invented by
Shugart Associates
•3.35-inch floppies were invented by
Sony.
•The typical 3.5 floppy drive holds 1.44
MB.
Drive
• Zip, the most popular super-capacity
floppy disks is the Zip disk.
• It holds 100M, which is 70 times as
much as 1.44M floppy
HARD DISK
• Might have a storage capacity of 40
gigabytes. This is about 300 times the
amount of storage in main memory
(assuming 128 megabytes of main
memory)
• Hard Drives are usually designated
as Drive C
• Hard disks are better than floppy
disks in three ways:
– Hard disks are sturdier than floppies
– Hard disks are hard and firm; they don’t
flop or jiggle. They’re more reliable than
floppies
– Hard drives hold more info. Than floppy
drives.
• The typical hard drive holds 40
gigabytes.
• The typical floppy disk rotates
between 5 and 10 times per second.
• The typical floppy disk rotates
between 5-10 times/second. The
typical hard disk rotates between 90167 times/second.
• The hard disk is non-removable
CD-ROMs
• CD that holds music is called a music CD
• A CD that holds computer data instead is
called a computer CD
• The standard CD-ROM disks has a
diameter of 12 centimeters and holds 650
megabytes.
• The CD can hold 99 tracks, totaling an
hour of music or 650 Mb.
CD-RW
• CD-rewritable drive, which can write
onto a blank CD-RW disk and then
edit what you wrote.
DVD
• 1997, the electronic industry selling
an improved kind of CD, called a
Digital Versatile Disk (DVD)
• Holds 2-hour movie (including the
video and sound)
• Movie Lovers call it a Digital Video
Disk
VIDEO CARD
• A board that pugs into a personal
computer to give it display capabilities
• Graphics Accelerator: adapters
graphics coprocessor for performing
graphics calculations
• Video Card are also called video
adapter, video board , video display
board, graphics card and graphics
UNDERSTANDING VIDEO
GRAPHICS
• The video/graphics card converts
digital data into signals that can be
sent across a connector to you
monitor, which interprets the signal
into an image on screen.
The End