Backing Storage Devices

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. 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.

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 Each 0 or 1

Byte 8 bits

Kilobyte Approximately 1,000 bytes Exactly 1,024 bytes

Megabyte Approximately 1 million bytes Exactly 1,048,576 bytes

Gigabyte 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 etc

Magnetic Storage

A fairly permanent type of storage that can be modified.

Recording of data onto disks or tape by magnetizing particles.

Floppy Disk Round piece of flexible 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

FormattedPreparing the disk for use by the computer.

Write-protectedSetting the disk so that it can not be written to

by the computer.

Zip Disk

Floppy disk technology manufactured by Iomega in late 1994.

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.

Digital Audio Tape (DAT) is a recordable audio format conceived by the Japanese in mid 80’s

Optical Storage

Means of recording data as light and dark spots on CD or DVD.

Reading is done through a low-power laser light.

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.

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 & data) and DVD’s (data or movie).