Computer Performance
& Storage Devices
Computer Technology
Computer Performance
Boot Process

Sequence of events that occurs
between the time you turn on a
computer and the time that it becomes
ready to accept commands.

Purposes
• Runs a diagnostic test to make sure
everything is working.
• Loading the operating system, so the
computer can carry out basic operations.
6 events of the boot process:
Power up
 Start boot program
 Power-on self-test
 Identify peripheral devices
 Load operation system
 Check configuration and
customization

Circuits


The path from one
component of a
computer to another
that data uses to
travel.
Circuits run between


RAM and the
microprocessor
RAM and various
storage devices
Silicon Chip


Silicon is melted
sand.
What the circuits
are embedded into
to keep them
together.
Megahertz (mHz)



A measurement used
to describe the speed
of the system clock.
A megahertz is equal
to one million cycles
(or pulses) per second.
1.3 GHz means that
the microprocessor’s
clock operates at a
speed of 1.3 BILLION
cycles per second.
Pentium


Name of the CPU.
Pentium is the 5th
generation of the
Intel processor.

Other generations
were called
•
•
•
•
80-88
286
386
486
RAM vs. ROM

RAM




“Random Access
Memory”
The ability of a storage
device to go directly to a
specific storage location
without having to search
sequentially from a
beginning location.
Very volatile
• Cannot hold data when
the power is off.
• Looses all data when
power is lost.
ROM



“Read only memory”
Drives can read data
from disks, but cannot
store new data on them.
One or more integrated
circuits that contain
permanent instructions
that the computer uses
during the boot process.
Binary Number System

A method for
representing letters
or numbers using
only two digits, 0 and
1.

Bit
• Each 0 or 1

Byte
• 8 bits

Also referred to as
Base 2 Binary Code.
Memory Measurements

Bit


Byte




Approximately 1 million
bytes
Exactly 1,048,576 bytes
Gigabyte


Approximately 1,000 bytes
Exactly 1,024 bytes
Megabyte


8 bits
Kilobyte


Each 0 or 1
Approximately 1 billion
bytes
Terabyte

Approximately 1 trillion
bytes
Storage Devices


Used to keep data when the power to the computer
is turned off.
Medium/media

Location where data is stored.
Hard Disk


Usually mounted
inside the
computer’s system
unit.
Can store billions
of characters of
data.

Stated in forms of
bytes:
• Megabytes or
Gigabytes
Magnetic Storage


Recording of data
onto disks or tape
by magnetizing
particles of an
oxide based
surface coating.
A fairly permanent
type of storage that
can be modified.
Floppy Disk



Round piece of flexible
Mylar plastic covered
with a thin layer of
magnetic oxide and
sealed inside a
protective covering.
May be referred to as a
“floppy”
3½ disk capacity is
1.44 MB or 1,440,000
bytes
Floppy Disk Options

Formatted


Preparing the disk for use by the
computer.
Write-protected

Setting the disk so that it can not be
written to by the computer.
Zip Disk

Floppy disk technology manufactured by
Iomega.

Available in 100 MB and 250 MB versions
Digital Audio Tape

Method of storing large amounts of
data on tape using helical scan
technology to write data at high
densities across the tape at an angle.
Optical Storage
Means of recording data as light and
dark spots on CD or DVD.
 Reading is done through a low-power
laser light.


Pits
• Dark spots

Lands
• Lighter, non-spotted surface areas
CD-ROM


“CD – Read Only Memory”
Also called CD-R


CD-Read
Storage device that uses
laser technology to read
data that is permanently
stored on compact disks,
cannot be used to write data
to a disk.
CD-RW



“CD-Read Write”
A storage device that reads data from CD’s and also
can write data to CD’s.
Similar to a CD-ROM, but has the ability to write to
CD.
DVD-ROM



“Digital Video Disks
– Read Only
Memory”
Reads data from
CD’s (audio and
data) and DVD’s
(data or movie)
Cannot be used to
write data to a disk.