Lecture 1: Basic Concepts of Information Technology: Computer Hardware PDF

Lecture 1 Basic Concepts of Information Technology: Computer Hardware Dr. Ali Alnoman Spring 2025 Computer ▪ A computer is an electronic device that is used to process data ▪ Used to store, retrieve, and process data according to a set of ins...

Lecture 1 Basic Concepts of Information Technology: Computer Hardware Dr. Ali Alnoman Spring 2025 Computer ▪ A computer is an electronic device that is used to process data ▪ Used to store, retrieve, and process data according to a set of instructions (program) given to it Input Output 2 Types of Computers Computers can be categorized into the following types: ▪ Personal Computers (e.g., laptop, desktop computer) ▪ Handheld Devices (e.g., smart phones) 3 Personal Computer ▪ In General, the term Personal Computer (PC) is used for any small computer ▪ A standard desktop PC comprises a Casing/Box, a monitor, a keyboard and a mouse, in addition to other devices 4 Laptop Computer ▪ A laptop is a portable computer which can be easily carried in a small bag/case ▪ Batteries are used to power laptops ▪ Has computing capabilities similar to that of a desktop computer 5 Handheld Devices: Smart Phones ▪ Cell phones are handheld computers with advanced features and capabilities 6 Mainframe Computers ▪ Powerful computers that perform huge amounts of tasks at a high speed ▪ Used by large organisations such an banks and postal services to control the entire business operation ▪ Expensive ▪ Require large space 7 Hardware ▪ The term hardware refers to the physical components of the computer such as the processor, memory, keyboard, monitor, etc. Software ▪ The software is a set of instructions that make the computer work ▪ Software can be generally divided into operating system and applications ▪ Software is mainly held in the hard disk or a portable storage device such as CD-ROM, and is loaded from the hard disk into the computer’s RAM (random access memory) in order to be processed by the CPU (central processing unit) 8 Von Neumann Computer Architecture 9 Main Parts of a PC ▪ Keyboard ▪ Mainboard (Motherboard) ▪ Monitor ▪ Central Processing Unit ▪ Mouse (CPU) ▪ Speaker ▪ Memory (RAM) ▪ Modem ▪ Hard disk drive (HDD) ▪ Case/Box ▪ CD-ROM Drive ▪ Wireless connectivity chips 10 Keyboard ▪ Used to input information into the computer ▪ Contains multiple characters and special-function ▪ Keys (buttons) ▪ QWERTY keyboards Mouse ▪ Used to control the computer ▪ With mouse we can select menu options, drag & drop, etc. ▪ Types: Ball (obsolete), optical ▪ Can be wired or wireless 11 Monitor ▪ Used to display information of the computer ▪ Monitors have different sizes ▪ Picture quality is described by resolution and the number of pixels System Case/Box ▪ A plastic or metal box that houses the essential computer parts such as the CPU, Motherboard, HDD, CD drive, etc. 12 Printers ▪ Printers are used to print text, pictures, and documents ▪ Inkjet printers, Laser printers Touch screens ▪ These are special monitors which are used not only to display information but also to take input 13 Graphic Tablet ▪ It is touch-sensitive pad. A Stylus (digital pen) is used for drawing or writing Scanner ▪ A scanner is used to convert printed papers into digital files 14 CD-ROM/DVD/BluRay Drive ▪ CD/DVD/BluRay drives are used to read/store information in optical disks MODEM ▪ A modem is a device that converts the digital data from computer into analogue signals for transmission through the network, and vice versa (MODulator, DEModulator) ▪ Modem can be internal or external 15 Input and Output Ports A port is a place where we can connect an external device to the computer Serial Ports ▪ Used to connect external devices such as a mouse or a keyboard ▪ Transfers data in a single (serial) stream Parallel Ports ▪ Used to connect external devices such as printers ▪ transfers data in multiple (parallel) streams 16 Universal Serial Bus (USB) Port ▪ This is the most common serial port and is widely used port to connect external devices ▪ Has no pins Network (Ethernet) Port ▪ This port is used to connect the PC to other devices/computers in the network 17 Central Processing Unit (CPU) ▪ CPU is the brain of the computer ▪ It performs processing and calculations of data ▪ Popular CPU manufacturers are Intel and AMD ▪ It tells how fast the computer will run and its speed is measured in GHz ▪ A 3 GHz CPU is faster than 1 GHz CPU 18 Central Processing Unit (CPU) ▪ Also referred to as the Processor ▪ Logically comprises the following components: ▪ Arithmetic and Logic Unit (ALU): which contains a set of functional units to perform arithmetic operations & logic operations to process data ▪ Control Unit: which controls the flow of data processing based on the instructions of the program ▪ Registers: smallest storage unit to process data in small pieces within the CPU ▪ Cache memory: fast and small memory that acts as a buffer between the processor and RAM ▪ Clock: a measure of the processing speed (cycles/second or Hz) 19 Memory ▪ Memory stores program data temporarily during processing ▪ Random Access Memory (RAM): allows to store and retrieve data (read and write) ▪ Data are lost when power is off (volatile) Hard Disk Drive (HDD) ▪ Used to store data permanently ▪ HDD can be external or internal ▪ Data are not lost when the power is off (non-volatile) 20 Random Access Memory (RAM) ▪ The main 'working' memory used by the processor ▪ Used to store data or programs on a temporary basis ▪ When we use a program, its data will be loaded into the RAM ▪ Also called Volatile Memory because when we turn off the computer, all data will be lost ▪ RAM size affects the performance of the computer (larger is better) 21 Memory ▪ Dynamic Random Access Memory (DRAM) is used to contain the instructions and data of a program; needs to be refreshed periodically (dynamic) ▪ “Random Access” means that memory access takes basically the same amount of time no matter what portion of the memory is being read ▪ Cache memory: inside the processor, used as a buffer between the CPU and RAM ▪ Cache memory is a Static Random Access Memory (SRAM) which is faster than DRAM but usually has less capacity ▪ SRAM and DRAM are two layers of the memory hierarchy 22 Memory Hierarchy 23 Memory Hierarchy 24 ROM – Read Only Memory ▪ Is a special type of memory that holds software and important information needed by the computer system ▪ Information in ROM can only be read (no write) ▪ ROM retains information even after the powered is off (non-volatile) ▪ An example of ROM is the ROM-BIOS chip, which contains read-only software used to start up the computer ▪ Network cards and video cards also contain ROM chips 25 Storage areas inside the computer ▪ The HDD can be divided into many parts (drives) ▪ Each section is represented by a character, e.g. (drive E:) ▪ System files are usually located in drive C 26 Opening the computer box 27 Storage in Computer ▪ The smallest unit of computer storage/memory is Bit ▪ A bit is either 1 or 0 (binary number) ▪ 1 Byte equals 8 bits ▪ 1000 Bytes can also be written as 1KB Below are the prefixes used in measuring computer storage: 28 Memory Sticks/Flash Memory ▪ Portable memory that can be plugged directly into the computer ▪ Fast to use and can store large amount of data ▪ Uses the Electrically Erasable Programmable Read only memory (EEPROM) technology in read/write data 29 Online (cloud) file storage ▪ Many websites provide the facility to save data on the Internet ▪ Help to store and access data anywhere and anytime ▪ Such services are becoming popular nowadays ▪ Examples: ▪ Software as a Service (SaaS): such as google apps, Webex meetings, dropbox, etc ▪ Platform as a service (PaaS): helps to develop applications such as Microsoft Azure ▪ Infrastructure as a Service (IaaS): provides hardware resources (e.g., processing, memory) such as Amazon Web Services (AWS) 30 Factors that affect computer performance ▪ We can roughly evaluate the performance of a computer using the following information: ▪ CPU speed ▪ RAM size ▪ Hard disk capacity ▪ Check your system information for CPU speed, RAM, and Hard disk Drive! 31 Information and Communication Technology (ICT) ▪ ICT is a term that refers to the integration of information and telecommunication technologies to facilitate information exchange ▪ Examples of ICT technologies include cellular networks (e.g., 4G, 5G), Internet of Things (IoT), Robotics, etc 32