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Computer Skills CIS 100 . 1 st semester 2013-2014. http://www.just.edu.jo/~mqais/CIS%20100.html. Ch.01 Introduction to Computers.
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Computer SkillsCIS 100 1st semester 2013-2014 http://www.just.edu.jo/~mqais/CIS%20100.html
Computers are electronic devices that can follow instructions to accept input, process the input and then produce information. It is a machine that manipulates data according to a set of instructions. • Computers are machines that perform tasks or calculations according to a set of instructions, or programs. • A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem. (Wikipedia free encyclopedia) What are computers?
Hardware غير مطلوبة فقط للفهم
HARDWARE SOFTWARE Computers are made of
Computers are made of Computers work through an interaction of hardware and software. Hardware refers to the parts of a computer that you can see and touch, including the case and everything inside it. The most important piece of hardware the central processing unit (CPU), or microprocessor.
Computers are made of Softwarerefers to the instructions, or programs, that tell the hardware what to do. Ex. operating system (OS), A word-processing program.
The parts of computer itself (tangible objects ) including : • Input devices i.e the keyboard and mouse • CPU (or Processor) and Primary memory (or Main Memory) • Output devices • Storage devices Hardware
Mother-Board (or Main Board) غير مطلوبة فقط للفهم غير مطلوبة فقط للفهم CPU RAM ROM
Input Devices • Translate data from form that humans understand to one that the computer can work with • Most common are keyboard and mouse Selector Buttons
Keyboard(QWERTY keyboard, ATMs keyboard) ATM: automatic teller machine • Mouse • Scanner • Optical mark recognition (Light Pin , Bar code scanners) • Microphone • Joystick . Examples of Input Devices See Page 4 in text book
Point and Draw devices • Trackball • Touchpad • Touch screen • Magnetic stripes and smart cars. • Digital Cameras Examples of Input Devices(2)
Central Processing Unit (CPU) • Is the portion of a computer system that carries out the instructions of a computer program, and is the primary element carrying out the functions of the computer or other processing device. • The speed (clock speed) of CPU measured by Hertz (GHz)
The CPU consists of : • Control Unit (CU) • Arithmetic and Logical Unit (ALU) • Some Registers
The Control Unit (CU) : coordinates all activities of the computer by: • Determining which operations to perform and in what order to carry them out. • The CU transmits coordinating control signals to other computer components.
The ALU : consists of electronic circuitry to perform: • Arithmetic operations (addition, subtraction, multiplication and division) • Logical operations (and, or, not, …) and to make some comparisons (less-than, equal, … etc.)
Memory (fast, expensive, short-term memory): Enables a computer to store, at least temporarily, data, programs, and intermediate results. • Two general parts: • RAM • ROM Primary Memory
its a primary storage or random access memory (RAM). • it temporarily holds data and programs for use during processing (volatile: information stored in RAM is lost when the computer is turned off). • RAM is the memory that the computer uses to temporarily store the information as it is being processed. The more information being processed the more RAM the computer needs. • RAM consists of locations or cells. Each cell has a unique address which distinguishes it from other cells. RAM (Main Memory)
Address Memory locations 1 2 3 n Memory Cell Main Memory
ROM is part of memory • Programmed at manufacturing time • Its contents cannot be changed by users • It is a permanent store Q: Mention some examples of ROM? A: (PROM & EPROM ) ROM: Read Only Memory
PROM: Programmable Read Only Memory. • EPROM: Erasable Programmable Read Only Memory • Cache Memory • Registers: not part of the main memory. Q : Registers are part of “ …… ” ? Other Kind of Memory
Secondary Storage • Stores data and programs permanently: its retained after the power is turned off • Examples • Hard Drive (Hard Disk) • Located outside the CPU, but most often contained in the system cabinet • Floppy Disk • Optical Laser Discs • CD-ROM, CD-RW, and DVD
Common Secondary Media • Diskettes • Data represented as magnetic spots on removable flexible plastic disks • Most common size is 3 1/2 inches, in a rigid plastic case • Disk drive holds the diskette, reads or retrieves the data and writes or stores data
Common Secondary Media • Hard drive • Data is represented magnetically as with diskettes • Normally more than one rigid platter in a sealed unit • These disks are not removable • Significantly more capacity and faster operating than diskettes
Common Secondary Media Hard drive
Common Secondary Media • CD ROM & DVD’s • Data is represented as pits and lands • Some kinds are read only (CD-ROM) and some Kinds are rewritable (CD-RW) • Significantly more capacity and faster operating thandiskettes Optical Laser Discs DVD: Digital Video Disk
Common Secondary Media • tapes • Panasonic's LS120 3.5 inch diskettes • Iomega's Zip & Jazz disks • VCR tape (Video Cassette Recorder ) • Flash USB disks • MMC (Multi Media Card ) • SD
CPU Output Devices • Pieces of equipment that translate the processed informationfrom the CPUinto a form that humans can understand. Processed information
Monitors • Printers • Dot matrix printers • Ink jet printers • Laser printers • Sound Blasters (Sound Card By Creative Lab) • Controlling other devices Output Devices
Software • A collection of computer programs and related data that provide the instructions for telling a computer what to do and how to do it.
1- System software: helps run the computer hardware and computer system. 2- Application software: allows end users to accomplish one or more specific (not directly computer development related) tasks. 3- Programming software : usually provides tools to assist a programmer in writing computer programs, and software using different programming languages in a more convenient way. Types of software
System Software The most important System Software is the Operating System Examples of operating systems: Windows XP (GUI: graphical user interface ) DOS (Command base), Apple, UNIX
System Software • The software that controls everything that happens in a computer. • Background software, manages the computer’s internal resources Resources examples : CPU, RAM , I/O devices, …
All hardware and software are under the control of the operating system. Among other things, the operating system: • Determines how valuable RAM is allotted to programs. • Performs tasks related to file management. • Sets priorities for handling tasks. • Manages the flow of instructions, data and information to and from the processor (CPU).
Examples ofMicrocomputer Operating System Software • DOS - original standard for IBM compatibles • Windows - a graphical operating environment • Windows VISTA, XP, millennium, 2000, 98, and 95 Continue …
Examples ofMicrocomputer Operating System Software Cont. • Windows NT - for powerful workstations & networks • OS/2 - competitor to Windows 2000 • Macintosh Operating System • Unix - originally for minicomputers, now used on microcomputers and Internet servers • Question: List some examples of operating systems ?
Application Software Packaged Custom • Packaged - “off the shelf”, pre-written programs ( General purpose) • Custom - written for an organization’s specific purpose (Special purpose)
Application Software – Basic Tools • Word processors– example: Microsoft word • Spreadsheets-- example: Microsoft Excel • Database managers-- example: Microsoft Access • Graphics-- example: Photoshop Spreadsheets: Computer software that allows the user to enter columns and rows of numbers in a accounting book like format.
Bit (Binary Digit)(takes two values: 1 or 0) • Byte = 8 bits • KB (Kilo-byte) = 1024 bytes • MB (mega-byte) = 1024 KB • GB (giga-byte) = 1024 MB • TB (Tera-byte) = 1024 GB Remark: 1024=210 Units of Measurements
Microcomputers 2. Minicomputers 3. Mainframe computers 4. Supercomputers Four Kinds of Computers
Comparison between the previous kinds of computers may made based on : • Price • Processing Speed • Storage Capacity • Powerful • Single-user or Multi-user • Supporting hundreds (or thousands) of users simultaneously • Computer Size • Companies size • …etc.
Microcomputer =>Personal Computer => PC • Personal Computer (PC): A small, single-user computer based on a microprocessor. Microcomputers
Small enough for a desktop, but not easily portable • Personal computers (PC’s) run general purpose software and are employed by a wide spectrum of users Desktop Computer
Easily transported from one place to another Portable Computers
Four categories • Laptops • Notebooks • Sub-notebooks • Personal Digital Assistants (PDA) • Q: list all portable computer categories? Portable Computers