Computer Parts

Two Basic Parts

Hardware&

Software

Computing SystemsComputers have two kinds of components:Hardware, consisting of its physical devices (CPU,

memory, bus, storage devices, ...)Software, consisting of the programs it has (Operating

system, applications, utilities, ...)

What is Hardware?Hardware is all the elements or pieces that

make up the of physical components of the computer

Consider it the physical machine.Hardware is anything that you can touch

Key Hardware ComponentsThe parts of the computer can be classified into 3 sections

CPU MemoryPeripherals & Connectors

Hardware: CPU

CPU - Central Processing UnitCPU is often called the brain of the computer

because that is where it does all the thinkingReceives program instructionsPerforms arithmetic and logical operationsControls other computer components

Consists of millions of transistors on a single microchip that plug into the motherboard

Speed of CPU is measured in Hertz – number of cycles/second

Today speed is measured in gigahertz (GHz) (billions of cycles per second

Memory

There are three main types of memory:

1. Cache Memory2. Random Access Memory (RAM)3. Persistent Storage (ROM)

Memory is where all the information is stored.

Without information the computer would be useless.

Hardware: CacheCache MemoryTemporary memory accessed by the CPUVery fast used at initial startup of computer Stores data and instructionsData is then sent to the other types of memoryStores frequently used instructions and data but quite smallTemporary – is not kept once the computer is shut down

Hardware: RAMRandom Access Memory (RAM)• Stores instructions and data• Temporary memory – not kept once the computer is

shut down• Size is dependent upon the computer• The more RAM memory the faster the computer. • It is fast, but volatile...• analogous to a person’s short-term memory.

Hardware: ROMPermanent Memory – Read Only Memory (ROM)• Stores data forever on you Hard-drive or data stick.• Older computers store information on magnetic or

optical media.PermanyStable storage using magnetic or optical media.

• Called Read Only Memory because it reads files and saves them (permanently)

• Analogous to a person’s long-term memory.• Slower to access than RAM• Cannot execute instructions

Basic Units of Memory

1 bit (0 or 1)1 byte normally consists of 8 bits

Is the storage for one character210 bytes =1024 bytes = 1 kiloByte (kB)1024 KB = 1 MegaByte (MB)1024 MB = 1 GigaByte (GB) Many people approximate in steps of 1000, not 1024

Example: a 20KB file actually has 20,480 bytes, not 20,000 bytes

Bits & BytesA bit is a 1 or a 0

They are stored in a memory address in groups of eight

8 bits = 1 byte which is the storage of one characterone byte, is the smallest unit of information that a

computer can process. 210 bytes =1024 bytes = 1 kiloByte (kB) 1024 KB = 1 MegaByte (MB) 1024 MB = 1 GigaByte (GB) Many people approximate in steps of 1000, not 1024

There are different data types for each of the many forms of data. The data type you choose will affect not only the form in which the data is stored, but also the amount of memory required to store the data.

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Hardware: Peripherals & Connectors

Peripherals: Input & Output Devices Input

Keyboard, mouse, digital pen, modem, wireless Internet connection, touch screen, joy sticks, and more

OutputMonitor, printer, speakers, modem, wireless Internet

connection, and more

Hardware: Peripherals & Connectors

Connector - The Bus:• Connects CPU to other hardware devices.• Analogous to a person’s spinal cord.• Speed measured in megahertz (like the CPU), but

typically much slower than the CPU...• The bottleneck in most of today’s PCs.

Hardware: How it WorksPutting the pieces together:

CPU

Bus

RAMMemory

ROMMemorycache

Programs are stored (long-term) in secondary memory, and loaded into main memory to run, from which the CPU retrieves and executes their statements.

What is Software?Software is information that can be stored

on the computersYou cannot touch softwareYou can only see the result of the

information on an output device like a monitor

Software is divided into two main categories

System SoftwareApplication Software

System SoftwareSystem software is the software that allows you to run the

computerIt controls and maintains the hardware. It is the interface between the hardware and the programs you

use on the computerTypes of system software:

Operating system Networking system Programming language software Web site server Data backup

Examples of system software: Linux, Windows, MacOS

Software: Operating System

Operating System (OS)The OS acts as the “manager” of the computer system,

making sure that each hardware device interacts with the others.

It enables the computer to communicate with software applications like Microsoft Word and you the user.

Examples: MacOS, Windows, Linux

Application SoftwareApplication software is all the software that allows you to work or

play on the computerIt is because of this software that we have to use computersYou will know this type of software as “program” Types of programs that are commonly used:

Word processors and spreadsheets (Word, Excel) Game programs Web browsers Photo Editors Email Graphics and Drawing

Networking and CloudsCan you imagine a world without Google?Today computers are all connected togetherA network is a collection of computers that can talk to

each otherThis world-wide collection of networks is called the

InternetThe internet makes use of two key pieces of application

software: Email and WWW

Programming LanguagesSoftware is a set of instructionsHow are instructions given to computers?

With programming languages There are three types of languages

1. Machine Languages Consists only of sequences of 0s and 1s example: 0110110111110111 0000000100000000 0000000100000000

2. Assembly Languages symbolic representation of machine language example: ADD A,B

3. High-level Languages contains English words and phrases and algebraic expressions examples of high level languages:

Python, Java, C++, VisualBasic, Fortran