Computer System Hardware Software

Computer Hardware A typical computer system consists of the following major components: The central processing unit (CPU) Main memory Secondary storage devices Input devices Output devices

Computer Hardware

The organization of the CPU Arithmetic & Logic unit (ALU) Control unit COORDINATES ALL OF THE COMPUTER’S OPERATIONS ALU is designed to perform mathematical operations

CPU images

THE CPU’S JOB

Fetch: The CPU’s control unit fetches, from main memory, the next instruction in the sequence of program instructions CPU RAM

THE CPU’S JOB Decode: The instruction in encoded in the form of a number. The control unit decodes the instruction and generates an electronic signal

The job CPU Execute: The signal is routed to the appropriate component of the computer (such as the ALU, a disk drive, or some other device). The signal causes the component to perform an operation CPU RAM DISK DRIVE

Computer internal memory RAM (Random Access memory) ROM (Read only memory) Cache memory

RAM

RAM (Random Access Memory) is a device that holds information RAM holds the sequence of instructions in the programs that are running and the data those programs are using

RAM Main memory is an ordered sequence of cells, called memory cells Each cell has a unique location in main memory, called the address of the cell When the computer is turned off, RAM loses its data

Memory capacity PrefixSymbo l Exponentia l NumericBinaryDecimal value KiloK10^31,0002^ MegaM10^61,000,0002^201,048,576 GigaG10^91,000,000,0002^301,073,741,824 TeraT10^121,000,000,000,0002^401,099,511,627,776 PetaP10^151,000,000,000,000,0002^50 ExaE10^181,000,000,000,000,000,0002^60 ZattaZ10^211,000,000,000,000,000,000,0002^70 YottaY10^241,000,000,000,000,000,000,000,0002^80

Binary Number System ^72^62^52^42^32^22^12^ Byte

Bit VS Byte Bits are used to measure data transfer speed rate as Internet connection (Example: 25Mbps) Bytes are used to measure file size and storage capacity (Example: 2GB)

Positive values Byte(s)bitsRangeValues … … 65, …4,294,967,

Negative & Positive values Byte(s)bitsRange … … ,147,483,648 … 2,147,483,

DDR2 VS DDR3 VS DDR4 RAM FeatureDDR2DDR3DDR4 TRANSFER RATE 400 MB/S – 1066 MB/S800MB/S-2133MB/S1600MB/S-3200MB/S MEMORY DENSITY 512MB – 8GB2GB – 16GB VOLTAGE1.8 VOLTS1.5 BOLTS

Secondary storage devices Hard disk drive (HDD) (External & Internal) Magnetic HDD Solid State Drive (SSD) Hybrid HDD DVD Blu Ray Flash Memory

Magnetic HDD VS SSD HDD VS SSD

USB PORTS PortSpeed Bits per second Characters per second USB Mbps (12*2^20) / 8 1,572,864 USB Mbps (480*2^20) / 8 62,914,560 USB Gbps (4.8*2^30) / 8 644,245,094 USB Gbps (10*2^30) / 8 1,342,177,280

HDMI PORT

CELLULAR NETWORT Type Speed Rate 3G 144 Kbps Kbps 4G 5 Mbps - 12 Mbps

Character representations in memory CharacterASCII (IN DECIMAL) UNICODE (IN DECIMAL) BINARY CODE # $ A B a b

SATA Explanation - Ports, Cables, Controllers, Motherboards SATA and IDE cables

Numbering systems Decimal (0 … 9)10 Binary (0 … 1)2 Hexadecimal (0 … 9, A, B, C, D, E, F)16 (0 … 9,10,11,12,13,14,15)16 Octal (0 … 7)8

Hexadecimal Number System ^32^22^12^02^32^22^12^0 33 Byte First digit Second digit

Octal Number System ^12^02^22^12^02^22^12^ Byte First digitSecond digit Third digit 2 Bit3 Bit

Types of Software System Software Application Software Utility Software

System software System software is a collection of one or more programs used to control and coordinate the hardware and other application software Communicates with hardware devices. Controls and monitors the proper use of various hardware resources like CPU, memory, peripheral devices like monitor, printer etc. Supports the execution and development of other application software.

System Software Examples Operating system Programming language translators Communication software Compiler and Interpreters

Operating System software Windows OS X operating system (MAC computers) Linux UNIX

Operating System software difference Security Stable User friendly Ease of use Multimedia capabilities

Utility Software Utility software is a collection of one or more programs that helps the user in system maintenance tasks and in performing tasks of routine nature. Utility programs help the users in disk formatting, data compression, data backup, scanning for viruses etc.

Utility Software examples Anti-virus Registry cleaners Disk defragmenters Data backup utility Disk cleaners

Application Software Application software is a collection of one or more programs used to solve a specific task. Generally software used in banking industry, airline/railway reservation, generation of telephone or electricity bills etc. all fall under application software.

Application Software examples Word processing software Spreadsheet software Database software Education software Entertainment software