ONTAP - Computer Hardware 2

ICT SHSM Certification Test – Part 2

Input Processing Output

Primary

Storage

Secondary

StorageNetworking

Architecture

Simple Model of a Computer – Review

Primary Storage

Primary Storage refers to a computer’s short-term memory. This is the computer’s RAM (Random Access Memory).

When the user launches an application, the most important parts of the software are loaded into RAM for quick access.

RAM is “volatile” – meaning that when the computer is turned off, the contents of RAM are erased.

Primary Storage

RAM comes in a variety of sizes and shapes, but must be compatible with the computer’s motherboard.

Secondary Storage Secondary storage refers to a computer’s

long-term memory.

This memory is “non-volatile”, meaning that even if a computer is turned off, the contents of secondary storage are preserved.

There are three types of secondary storage:MagneticOpticalFlash

Secondary Storage

Magnetic memory deals with tapes or disks coated with magnetisable particles.

When writing to this type of memory, an electromagnet on the read/write head is used to align the particles in a particular way – representing the 1s and 0s.

When reading from this type of memory, the demagnetised read/write head detects the polarity of each particle to translate the data back as 1s and 0s.

Secondary Storage

Hard disk drives are examples of magnetic storage, as are previously-used types of memory including floppy disks and tapes.

Floppy Disks

Magnetic Tape

Hard Drive

Secondary Storage

Optical drives are disk drives that create and/or play back CDs and/or DVDs.

Optical drives use laser technology. When a laser is shone onto the surface of an optical disk, the amount of light reflected back allows the computer to read the 1s and 0s representing the data.

In CD/DVD “burners”, a secondary laser is used to mark the surface of a blank disk with a pattern representing the data.

Secondary Storage

An internal view of a

CD/DVD-ROM.

Secondary Storage

Flash memory refers to the type of storage used by USB “thumb drives” as well as memory cards for cameras and portable gaming systems.

Flash memory is called “solid-state” memory because it does not involve any moving parts.

USB Flash Drives

Architecture

Architecture refers to the parts of a computer that connect all the other parts together. This includes:Motherboard – all parts connect here through the

appropriate ports and slots.Case – holds all parts in one place, has

power/reset buttons.Power Supply – plugs into a wall socket and

provides the right voltage to each componentFan – keeps the computer cool, prevents over-

heating

Architecture

Motherboard

Power Supply

Computer Case

Networking Networking hardware refers to those components

which allow a computer to communicate with other computers.

Networking includes using local networks (just one machine to another) and communicating over the internet (worldwide network of networks).

Both types of networks require a network interface card in each computer, along with a cabled or wireless connection.

Other network hardware includes the router, hub and modem.

Networking

Network Interface Card Modem

Router