MIS 105 INTRODUCTION TO COMPUTERS

The Lecturer Molla Ehsanul Majid BSc Engg (BUET) MCS (UOW, AUS) MT (UWS, AUS) One SAP Training (Senior SAP Training Consultant) Australian Public Education System (Educator) 2MIS 105 Introducing Computer Systems

Exploring Computers & Their Users The computer defined:  An electronic device that process data, converting it into information that is useful to people  May be for individual use or organisational use  Early Analogue Computers were mechanical devices weighing several tons and using motors & gears to perform calculations  Modern Digital Computers use binary numbers (sets of 0s and 1s) to perform calculations; small in size MIS 105 Introducing Computer Systems3

Exploring Computers & Their Users Computers for individual users: ◦ One user per machine at any time. ◦ Also known as Personal Computers (PCs) or microcomputers ◦ Six primary types in this category:  Desktop computers  Workstations  Notebooks  Tablet PCs  Handheld computers  Smart phones MIS 105 Introducing Computer Systems4

Exploring Computers & Their Users - Computers for individual users Desktop computers:  Often termed as Personal Computers or PCs  Designed to sit on a desk  A very wide range of users - from preschoolers to nuclear physicist  Two main types:  Horizontally oriented unit – lies flat on the desktop  Vertically oriented unit – tower type MIS 105 Introducing Computer Systems5

Exploring Computers & Their Users - Computers for individual users Workstations:  A specialized, single-user system  More powerful than a PC  Popular among scientists, engineers and animators  More speed, & memory, high resolution monitor, greater space Sun workstation MIS 105 Introducing Computer Systems6

Exploring Computers & Their Users - Computers for individual users Notebook computers:  Easily fits inside a briefcase  Also known as laptop computers as people usually use them on laps  Operate either on Alternating Current (AC) or batteries  Becoming more and more popular due to increased power and speed  Docking station: an unit that helps a notebook to be used as a PC; often includes larger monitor and additional ports MIS 105 Introducing Computer Systems7

Exploring Computers & Their Users - Computers for individual users Tablet PCs:  Smaller than notebooks in size  Uses specialised version of softwares and Operating System  Often uses a special digital pen called a Stylus Pen which is used to write directly on screen  Few models have special folded keyboard that can be used as a notebook  iPad is a popular Tablet PC MIS 105 Introducing Computer Systems8

Exploring Computers & Their Users - Computers for individual users Handheld PCs:  Small enough to fit in hand  PDA (Personal Digital Assistant) is a popular type of handheld computer  Mostly used as an organiser, eg, to take notes, display telephone numbers and addresses etc  Many PDAs come with internet access and Wi-Fi options MIS 105 Introducing Computer Systems9

Exploring Computers & Their Users - Computers for individual users Smart phones:  Cellular phones with advanced features are called smart phones  Features may include access, specialised software applications (apps), digital camera, music player, miniature keyboard etc MIS 105 Introducing Computer Systems10

Exploring Computers & Their Users -Computers for Organizations ◦ Have many user at the same time ◦ Used by organizations, schools, businesses etc ◦ Mainly four types:  Network Servers  Mainframe Computers  Minicomputers  Supercomputers MIS 105 Introducing Computer Systems11

Exploring Computers & Their Users -Computers for Organizations Network Servers:  A powerful personal computer with special software and hardware installed  Works as the primary computer in the network  All other personal computers in the network are connected to this central server  Clusters or Server farms: A network with dozens or hundreds of network servers working together  Blades: Servers reduced to a smaller unit  In a large organization different groups of servers may have different tasks; some for website hosting, some for , some for database, some for printing etc  Servers may be accessed through a PC, or handheld devices MIS 105 Introducing Computer Systems12

Exploring Computers & Their Users -Computers for Organizations Mainframe Computers  Are used in large organizations where many people frequently need to use the same data  Terminal: A device used to access mainframe data  Dumb terminal: Does not process or sort data; just can access data, usually an input/output device that functions as a window located into a computer located somewhere  Intelligent terminal: Can perform some processing operations, but usually does not have any storage  Although very powerful, are usually designed to perform a specific task, therefore less flexibility. Eg, flight reservation mainframe MIS 105 Introducing Computer Systems13

Exploring Computers & Their Users -Computers for Organizations Minicomputers:  Comparatively small size  In terms of capability, it falls somewhere between PCs and mainframes  Often called midrange computers  Can serve the input and output needs of hundreds of users Supercomputers:  Most powerful computers today with hundreds or thousands of processors; physically large  Can perform trillions of calculation per second  Used in the mapping of human genome, modelling nuclear fission, forecasting weather etc MIS 105 Introducing Computer Systems14

Inside the Computer System A complete computer system is comprised of four parts:  Hardware  Software  Data  User Information processing cycle:  A set of steps computer follows to receive data, process the data according to the instructions from a program, display the resulting information to the users, and store the results  Has four parts:  Input – a source eg, a program or a user providing instruction  Processing – performs action on the data based on input instruction  Output – display result on the monitor or send data to the printer  Storage – permanently stores results on the disk MIS 105 Introducing Computer Systems15

Inside the Computer System Essential Computer Hardware:  A computers hardware devices fall into one of four categories:  Processor  Memory  Input and output  Storage MIS 105 Introducing Computer Systems16

Inside the Computer System - Processing Devices Processor:  Like the brain of the computer. Organizes and carries out instructions that come from the user or software Microprocessors:  A processor usually consists of one or more microprocessors Motherboard:  A circuit board that interconnect other hardware such as processor, hard drive, memory, sound card etc Central Processing Unit (CPU):  Processors can be of a single chip or many chips. In either case the term CPU refers to a computer’s processor MIS 105 Introducing Computer Systems17

Inside the Computer System - Memory Devices Random Access Memory (RAM)  Temporarily holds data for faster access by programs  Volatile; erases all data when computer turned off  The more RAM, the faster the computer  Measured in Kilobytes, Megabytes (MB) or Gigabytes (GB) Read-Only Memory (ROM)  Permanently stores data, even when the computer turns off  ROM holds instructions that computer needs to operate  Eg, CD-ROM, DVD-ROM MIS 105 Introducing Computer Systems18

Inside the Computer System - Input and Output Devices Input devices:  Accept instructions from the user or another computer system and deliver this to the computer for processing.  Mouse, joystick, scanner, digital camera, keyboard, microphone etc are input devices Output devices:  Output devices present processed data to the user  Monitor, printer, speakers etc are output devices A touch screen is both an input and output device MIS 105 Introducing Computer Systems19

Inside the Computer System - Storage Devices ◦ Stores data. Three main types:  Magnetic storage: uses a round disk that spins around its center. Contains a Read/write head that reads data from the disk or write data onto it. Eg, hard drive  Optical storage: Devices that use lasers to read data from the surface of an optical disk or write onto it. Eg, CD-ROM, CR-RW, DVD-R etc  Semiconductor storage type: Device that use semiconductor chip to store data. Eg, Non-volatile type (Flash drive, memory card) and Volatile type (RAM) MIS 105 Introducing Computer Systems20

Softwares Mainly of two types:  System Software: Programs that are used to control computer’s hardware or for maintenance purposes so that the computers functions smoothly,  operating systems (windows 7, windows XP),  Network operating systems (windows server),  Utility softwares (Norton’s Antivirus, disk defragmenter etc)  Application Software: Used to accomplish a specific task. Eg, Word processing software (MS Word), Spreadsheet software (MS Excel) etc MIS 105 Introducing Computer Systems21

Computer Users User’s role:  Setting up the system  Installing software  Running programs  Managing files  Maintaining the system Userless computers;  Controlled by special operating instructions  Eg, washing machine, robot etc MIS 105 Introducing Computer Systems22

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