Transcript Computer Performance Storage Devices & Size

Computer Performance
& Storage Devices
Fremont High School
2009-2010
D. Beecroft
Computer Performance
Fremont High School
2009-2010
D. Beecroft
Boot Process

Causing the computer to start
executing instructions. These
instructions search for the operating
system, load it and pass control to it.

Purposes
• Runs a diagnostic test to make sure
everything is working.
• Loading the operating system, so the
computer can carry out basic operations.
Fremont High School
2009-2010
D. Beecroft
6 events of the boot process:
Power up
 Start boot program
 Power-on self-test
 Identify peripheral devices
 Load operating system
 Check configuration and
customization

Fremont High School
2009-2010
D. Beecroft
Circuits


The path from one
component of a
computer to another
that data uses to
travel.
Circuits run between


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2009-2010
RAM and the
microprocessor
RAM and various
storage devices
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Silicon Chip

A silicon chip is a piece of almost pure silicon,
usually less than one centimeter square and
about half a millimeter thick. A silicon chip
contains millions of transistors (devices that
control the flow of electric current) and other
tiny electronic circuit components, packed and
interconnected in layers beneath the surface.
There is a grid of thin metallic wires on the
surface of the chip, which is used to make
electrical connections to other devices.
Fremont High School
2009-2010
D. Beecroft
Megahertz (mHz)


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2009-2010
A measurement used
to describe the speed
of the system clock.
A megahertz is equal
to one million electrical
cycles (or pulses) per
second.
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Pentium


Name of the CPU.
Pentium is the 5th
generation of the
Intel processor.

Other generations
were called
•
•
•
•
80-88
286
386
486
Fremont High School
2009-2010
D. Beecroft
RAM vs. ROM

RAM



“Random Access
Memory”
A computer chip or
group of chips
containing the
temporary, or volatile,
memory in which
programs and data are
stored while being used
by a computer.
Fremont High School
2009-2010
ROM



“Read only memory”
Drives can read data
from disks, but cannot
store new data on them.
A computer chip on the
motherboard of a
computer containing
permanent, or
nonvolatile, memory that
stores instructions.
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RAM ~ Demonstration

Microsoft Word application,
the file that is being edited,
and operating system are
first loaded into Ram.
Fremont High School
2009-2010
D. Beecroft
Binary Number System


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2009-2010
A number system with a
base of 2. Only uses two
numbers (0 and 1).
 Bit
• The smallest unit
of data a
computer can
understand and
act on.
 Byte
• A combination of
eight bits (0’s and
1’s).
Also referred to as Base
2 Binary Code.
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Memory Measurements

Bit


Byte






Approximately 1 billion bytes
Approximately 1,000
megabytes
Terabyte


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Approximately 1 million bytes
Approximately 1,000 kilobytes
Exactly 1,048,576 bytes
Gigabyte


Approximately 1,000 bytes
Exactly 1,024 bytes
Megabyte


8 bits (group of 8)
Kilobyte


Each 0 or 1
Approximately 1 trillion bytes
Approximately 1,000 gigabytes
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Storage Device

A hardware component that houses a secondary
storage medium.
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Hard Disk

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A secondary storage
medium consisting of one
or more rigid metal
platters (disks) mounted
on a metal shaft and
sealed in a container,
called a disk drive, that
contains an access
mechanism used to write
and read data.
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Magnetic Storage Device

A storage device that works by
applying electrical charges to iron
filings on magnetic storage media,
orienting each filing in one direction
or another to represent a “0” or a “1.”
Data are stored and retrieved, or
accessed, either sequentially or
directly.
Fremont High School
2009-2010
D. Beecroft
Magnetic Tape Storage

A type of secondary storage for large
computer systems that used
removable reels of magnetic tape.
The tape contains tracks that extend
the full length of the tape. Each track
contains metallic particles that are
magnetized, or not magnetized, to
represent 0 and 1 bits.
Fremont High School
2009-2010
D. Beecroft
Digital Audio Tape

A signal recording and
playback medium
developed by Sony in the
mid 1980s. In
appearance it is similar to
a compact audio
cassette. As the name
suggests, the recording is
digital rather than analog.
DAT has the ability to
record at higher, equal or
lower sampling rates than
a CD.
Fremont High School
2009-10
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Floppy Disk

A secondary storage
medium consisting of a
thin, circular mylar
wafer, sandwiched
between two sheets of
cleaning tissue inside a
rigid plastic case.
Fremont High School
2009-2010
D. Beecroft
Write Protection

Any physical mechanism that
prevents modification or erasure of
valuable data on a device. Most
commercial software, audio and video
is sold pre-protected
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2009-10
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Formatting

The procedure of preparing a disk for
use during which the disk surface is
arranged into tracks, sectors, and
clusters.
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Formatting a Disk




Sectors: Pie shaped wedges.
Tracks: Concentric tracks arranged on the disk.
When users write data and store programs to
the disk, the tracks are encoded with 0 and 1
bits.
Cluster: The part of a track crossed by two or
more side-by-side sectors forms a cluster. The
smallest addressable unit of disk storage.
FAT: The outside tracks contain a table, called
the File Allocation Table (FAT), which keeps
track of where programs and files are stored.
Fremont High School
2009-2010
D. Beecroft
Zip Disk

Higher-capacity floppy disk provides large
secondary storage capacities.

Available in 100MB, 250MB, and 750MB
versions.
Fremont High School
2009-2010
D. Beecroft
Jaz Cartridge

A removable hard disk from Iomega.

Available in 1 or 2 gig versions.
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Optical Disk

A secondary storage medium on
which data is recorded and read by
two lasers. An optical disk can store
several gigabytes of data.

High density laser
• Records data by burning tiny
indentations, or pits, onto the disk
surface.

Low density laser
• Reads stored data from the disk into the
computer.
Fremont High School
2009-2010
D. Beecroft
CD-ROM


“Compact Disk – Read
Only Memory”
A disk technology in
which data is
permanently recorded
on an optical disk and
can be read many
times, but the data
cannot be changed.
Fremont High School
2009-2010
D. Beecroft
CD-R
“Compact Disk-Recordable”
 A disk technology that allows a user to
write data onto a compact disk. The
disk can be written on only once,
cannot be erased, but can be read
from an unlimited number of times.

Fremont High School
2009-2010
D. Beecroft
CD-RW


“Compact Disk-Rewritable”
A newer type of optical disk storage technology that
uses an erasable disk on which a user can write
multiple times.
Fremont High School
2009-2010
D. Beecroft
DVD-ROM


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2009-2010
“Digital Video Disk –
Read Only Memory”
An extremely high
capacity disk
capable of holding
several gigabytes of
data, such as a
movie.
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Resources
Fuller, Floyd. Computers: Navigating
Change. EMC Paradigm, 2002.
Parsons, June Jamrich, and Dan Oja.
Computer Concepts. Boston: Course
Technology - Thompson Learning, 2002.
Shelly, Gary B.; Cashman, Thomas J.;
Vermaat, Misty E. Discovering Computers
2003. Boston: Course Technology –
Thompson Learning, 2002.
http://cil.usu.edu/comptech/OSTutorial/
Fremont High School
2009-2010
D. Beecroft