Created by Michael Tsakrios ICAU2005B Operate Computer Hardware.

Created by Michael Tsakrios

ICAU2005BOperate Computer

Hardware


What is a Computer?

A computer is an electronic device that:

o Accepts data inputo Processes datao Produces data outputo Stores data (memory)


Hardware / Software

A computer comprises of hardware and software

o Hardware refers to the physical components that make up the computer system

o Software refers to the coded instructions known as programs which operate the computer


Hardcopy / Softcopy

Computer documentation can take the form of either a hardcopy or softcopy

o Hardcopy refers to a printed document, a document printed on paper

o Softcopy refers to an electronic document, a document displayed on a computer screen


Hardware

Computer hardware consists of the following devices:

o Input deviceso Processing deviceso Output deviceso Memory Storage devices


Input Devices

Input devices accept data input from the user, examples of input devices are:

o Keyboardo Mouseo Scanner


Processing Devices

Processing devices are used for processing data input to produce data output, examples of processing devices are:o The CPU (Central Processing Unit)o The Motherboard


Processing Devices - CPU

The CPU (Central Processing Unit) is the computer chip responsible for processing and executing instructions and performing calculations.

The CPU controls the input and output devices, it processes instructions from the input devices and in turn delivers the executing instructions to the output devices.


Processing Devices – CPU Clock Speed

The CPU clock speed is the speed at which a CPU processes and executes instructions. The clock speed of a CPU is measured in Hertz (Hz), or cycles per second, for example:

o A CPU with a speed of 400 Megahertz (MHz) is capable of processing and executing 400 million instructions per second

o A CPU with a speed of 4 Gigahertz (GHz) is capable of processing and executing 4 billions of instructions per second


Processing Devices - Motherboard

The motherboard is the main circuit board which houses the CPU, it provides the power and data infrastructure which allows all components to interact.


Output Devices

Output devices are used to deliver information to the user, examples of output devices are:

o Monitoro Printero Speakers


Input / Output Devices - Modem

The Modem allows users to access the Internet through a telephone line. The modem works as both an input and output device, for example:

o An Output device when requesting

information from the internet (requesting a Web page), this is known as uploading

o An input device when receiving information from the internet (displayed a Web page), this is also known as downloading


Memory Storage Devices

Memory storage devices are used to store software programs (applications) and data (information). There are two types of memory, main memory and secondary memory.

Main memory is also known as working memory, it stores whatever is currently being processed, main memory uses a primary storage device. Secondary memory stores everything which is not currently being processed, secondary memory uses a secondary storage devices.


Memory Storage Devices

Examples of storage devices are:o RAM (Random Access Memory) - Primary o Internal HDD (Hard Disk Drive) -Secondary

o External HDD - Secondaryo 3½" Floppy Disk - Secondaryo Optical Disk - Secondaryo USB Drive - Secondary


Bits and Bytes

What is a Bit?A bit is a binary digit, either 0 or 1.

What is a Byte?A byte is a combination of 8 bits. As a rule of thumb 1 keyboard character equals 1 byte.


Binary

What is Binary?

Binary is a base-two numbering system which contains only two values, 0 and 1.

Computer programs are executed in binary form, on / off signals, 1 represents on(voltage is presence), 0 represents off (voltage is absence).


Storage Devices - RAM

RAM (Random Access Memory) is working memory used for running programs and temporarily storing data. Random access refers to the fact that any part of the memory can be directly accessed.

RAM is volatile memory because data in RAM will be lost if the power is switched off before it is saved to disk.

Storage Devices - RAM(continued)

RAM consists of a set of chips that stores data and instructions.

The chips contain thousands of transistors that can switch on or off ( 1 or 0).



Storage Devices - Internal HDD

The internal HDD is a high capacity storage device housed inside the computer system, it stores the main software the system requires to operate.

The HDD is made up of one or more rigid plates coated with a metal oxide, this metal oxide allows data to be magnetically recorder onto the plates surface.

The internal HDD is also known as the:o Local drive o C:/ drive


Storage Devices - External HDD

An external HDD is very similar to an internal HDD, it is mainly used for backing up data (information).


Storage Devices - USB Drive

A USB (Universals Serial Bus) drive is a small lightweight portable removable and rewritable storage device that uses flash memory.

Flash memory is a form of non-volatile memory that can be electrically erased and reprogrammed.


USB Drive (Continued)

A USB drive is also known as:o USB sticko Flash driveo Thumb driveo Jump driveo Pen drive

Putting it all Together

CPU performs what is known as the fetch-execute cycle (fetch, decode, execute and store). The diagram below is a basic data flow diagram illustrating this cycle.


CPUInput

DevicesOutput Devices

Secondary Storage

Main Memory

Video

Simple Schematic Diagram -Interconnection Computer

Componentsa



Software

Software refers to the coded instructions known as programs which operate the computer

Computer software can be divided into two categories:o System Software o Application Software


System Software

System software are programs which manage the operation of the computer itself, the most important of these programs is the operating system.

When a computer is started the system software is loaded from the hard drive into RAM (this is known as the boot process). The system software control all the computer’s resources which allow the user to communicate with the computer and operate the application software (Microsoft Word etc).

Without the system software the computer is useless.


Application Software

Application software are programs that operate on top of the system software, they are designed to processes data for the user.

Examples of application software are: o Word processor programso Spreadsheet programso Database programs

Open Source Software

Open source software is software which is made available to users for free. The program’s code is made available for users to read and change it as they wish.

Linux is an example of open source software.


Computer Platforms

A platform is something upon which something else can be placed upon.

Computer Platforms refers to the computer’s hardware and software that defines how a computer operates, and determines what types of software can be used.


Hardware Platforms

Hardware platforms refers to the physical hardware onto which software is installed. Hardware platforms are built around the system’s CPU architecture, for example:o The x86 architecture refers the Intel CPU

used by PCso The 680x0 architecture refers to the

Motorola CPU used by Macso Other examples include mobile phones

and video game consoles.


Software Platforms

Operating Systems are a type of software platform. Examples include:o Windowso Linuxo MAC OS X o Android (used with mobile devices)

Software platforms create the framework for the application programs you use.


Platform Interaction

System Software executes the application software

The application software employees the system software to allow user interaction, read and write, print, etc .


System Case

The computer system case houses the motherboard and CPU assembly, RAM, power supply, cooling fans, internal disk drives, and the expansion cards that are connected into the motherboard.


System Case -Rear View


Created by Michael Tsakrios ICAU2005B Operate Computer Hardware.

Documents

examples of processing

examples of input devices

following devices

examples of output devices

processing data input

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