Presentation on theme: "Information Technology Ms. Abeer Helwa. Computer Generations First Generation (Vacuum Tubes) -They relied on the machine language to perform operations."— Presentation transcript:
Computer Generations First Generation (Vacuum Tubes) -They relied on the machine language to perform operations. -They were huge in size. -They were very expensive. -They had very low processing speed.
Computer Generations Second Generation (Transistors) -It is smaller. -It is faster. -It is cheaper.
Computer Generations Third Generation (Integrated Circuits) -The speed and the efficiency of the computers were increased.
Computer Generations Fourth Generation (Present Microprocessor) -The most powerful. -Can be linked together to form networks. -They are the fastest and the most efficient.
Definitions Computer: A computer is an electronic machine that receives input, stores and automatically processes data, and provides output in a useful format. Information Technology: A term that refers to both the hardware and software that is used to store, retrieve and manipulate information.
Definitions Data: Data is raw & unorganized facts and figures that need to be processed. Information: When data is processed and organized so as to make it useful and meaningful, it is called Information..
Advantages of computers Speed and accuracy of calculations and processing. Save huge amounts of data. Economic in cost and time. Network communications.
Super computer The biggest and the most powerful. They are rare because of their cost and size. Used by companies like NASA.
Mainframe computer Great processing speed and data storage. Often connected to many individual PCs with limited processing capabilities called dumb terminals. Used in Banks, Airlines etc.
Minicomputer Minimized in size and power. They are not used very commonly these days.
Microcomputer Called Personal computer (PC) It is small enough to fit on top of a desk, which can be used by one user at a time. Used in homes, schools etc..
Workstation Computer High-end microcomputer. Used by one person at a time. They are commonly connected to a local area network The workstation term can be also used to refer to a PC connected to a network.
Control computer Used for controlling operations in industrial, medical devices and travel media like planes and cars Also used to alert in any dangerous case.
CPU ( Central Processing Unit ) The most important part of a computer system. Usually referred to as the brain of the computer. It determines the speed of your computer which measured in MHz or GHz. 1 GHz= 1000 MHz
CPU ( Central Processing Unit ) CPU consists of: CU (Control Unit): It tells the computer system how to carry out program instructions from the memory. It controls and coordinates all activities of the computer. ALU (Arithmetic and Logic Unit): It performs mathematical and logical operations
a) RAM (Random Access Memory) The operating system is loaded into the RAM when you switch on your computer. Used to store applications that you are currently working with. It is temporary (volatile).
b) ROM (read only memory) It has special programs which are built-in when you buy the computer. Used to store control programs. It is permanent (non-volatile)
Storage Devices Hardware devices which are used to record and store data.
1) Internal storage Hard disk: It is the most important storage media in the computer. It stores operating system and programs.
2) External Storage a) Flash Memory A compact and easy-to-use device for transferring data between computers.
b) CD (Compact Disk) An optical disk which uses laser to read information. It has 750 MB capacity.
c) DVD (Digital Versatile Disk) A high-density video disc that stores large amounts of data, especially high-resolution audio- visual material like movies, encyclopedia etc. The capacity is up to 17 GB.
Disk and memory capacity The first level of storage is called bit ( the bit is referred to a binary number 0 or 1). Byte = 8 bits. Kilo Byte (KB) = 1024 bytes. Mega Byte (MB) = 1024 KB. Giga Byte (GB) = 1024 MB. Tera Byte (TB) = 1024 GB.
Computer Performance 1.The speed of the processor. 2.The capacity of RAM. 3.The capacity and the speed of the Hard disk. 47