3 Basic Components of the Computer System

3 Basic Components of the Computer System 1. Hardware – refers to the tangible components of a computer system 3 Hardware Components a. Input Devices b. Output Devices c. System Unit 2. Software – the component of the computer system which refers to the set of instructions written in a code 3. Peopleware – made up of the people responsible for maintaining, operating, programming and analyzing the output generated by the computer system

HARDWARE INPUT DEVICES – perform the two basic computing tasks: issuing commands and entering data. Data entry is defined as the process of entering data into the computer memory and issuing commands that tell the processor how to work with the data. 1. Keyboard – the standard input device of most computer (Esc key, Function keys, Return or Enter key, The space bar and Cursor keys)  Escape (Esc) key – used to stop a task in progress or to exit from an application  Function keys – used to perform specific commands or instructions for a specific program  Backspace key – used to delete the last character type  Enter or Return key – used to move down one line  Space bar – used for generating spaces  Cursor keys – used for moving up, down, left or right 2. Mouse – hand-clicked device used for pointing  Douglas Englebart – invented the mouse 3. Trackball – it is like a stationary, upside down mouse. 4. Joystick – commonly used for games 5. Light Pen – used to draw, write, or issue commands when it touches a specially designed screen 6. Video Input Devices – with a video digitizer, you can use images video cameras, camcorders, VCRs, and optical disk players as input to computers 7. Text Input Devices / Optical Reading Devices  Optical Character Readers – can read alphanumeric and special characters  Scanner – light-sensitive device to enter text and graphics a. Flatbed scanner – ideal for materials printed in a flat surface b. Hand-held scanner – used to capture images in materials which are not flat  Optical Mark Readers – detect the presence or the absence of marks on paper  Bar Code Readers – read and decode date from bar codes  Hand Print Readers – similar to OCR. However, they read handwritten characters instead 8. Magnetic Ink Reading Devices (MICR) 9. Audio Input Devices – allow you to communicate to the computer through speech and the like  microphone – used to capture sound SYSTEM UNIT – part of the computer which is responsible for accepting and processing the data brought in by the input device 1. Main Circuit Board – the central nervous system of the computer  Motherboard – main circuit board

2. Port – a connection from the main circuit board to a peripheral device such as keyboard, a printer or a video monitor 3. Expansion Slots – long plug-in strips in the main circuit board  disk drives  Audio  scanners  TV tuner  external CD-ROM  Networking  Modems 4. Bus – responsible for transporting electronic signals – from to place to place on specific predefined routes 5. Central Processing Unit (CPU) – computer’s processing, control and internal storage circuitry  microprocessor – composed of number of a number of components: Control Unit (CU) and the Arithmetic Logic Unit (ALU) 3 components that perform the processing function 1. CU 2. ALU 3. Main Memory (RAM and ROM) Control Unit – part of the CPU that directs the step-by-step operation of the computer Arithmetic Logic Unit – capable of performing arithmetic (add, subtract, divide and multiply) and logical operations (greater than, less than, equal to) A typical processing sequence Primary Memory (RAM)

Storage Operation (3)

Secondary Storage

Processing Operation

(2) Input Device (ex. Keyboard)

Input Operation (1)

Central Processing Unit

Output Operation (4)

Output Device (ex. Printer)

6. Registers – high-speed temporary storage areas which are used to hold both instructions and data during processing  instruction register – holds an instructions – for example, to add, to multiply, or to perform a logical comparison  buffer register – temporarily holds data retrieved from the primary memory, prior to processing  accumulator – temporarily stores the results of continuing arithmetic and logical operations OUTPUT DEVICES Forms of computer-generated output: 1. Text Output – simply alphanumeric characters that make up our language 2. Graphic Output – includes line drawings, maps, business presentation graphics, computer-aided design, computer graphics, and photographic reproduction 3. Sound Output – ranges from the message beeps produced by the computer system to the human voice to music 4. Video Output – refers to photographs or moving images such as television and videotaped material Types of Output Devices 1. Printer – provides hard copy output on paper

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Impact printer – produces an output using mechanism that presses against an inked ribbon on paper a. Dot-matrix b. Letter-quality  Non-impact printer – uses a photocopier-like process to transfer ink to a piece of paper  Plotter – a specialized kind of printer which is used for producing large and complex scientific and engineering hard copies such as plans and maps. 2. Video Monitors or Display – used to provide soft copy output 3. Speakers – used for audio output such as beeps, human voice and music. 4. Modem – used to connect one computer to another via conventional telephone lines (modulation – digital to analog; demodulation – analog to digital)

SOFTWARE -

another name for these set of instructions is program

2 Types of Software 1. Systems Software – tell the CPU what to do; a more common type is Operating System (OS) – refers to the programs that manage and support the resources and operations of a computer as it performs various data processing tasks 2. Applications Software – refers to the programs that enable the computer to perform specific data-processing tasks as required by the user a. b. c. d. e.     

5 Groups of prewritten applications software General Business Packages – generic software that can be used by businesses (ex. inventory, payroll, or accounts receivable system) Industry – Specific Packages – software created to meet specific needs of industries Organizational Productivity Packages – software aiming to meet the needs of the organization as a whole by empowering members of the organization to accomplish more with less effort (ex. group decision support systems, project management systems, etc.) Games and Entertainment – software address the need of the individual for PC-based entertainment. Personal Productivity Packages – programs that seek to empower the individual with tools which he or she can tailor to best suit his or her own specific needs, thus making him or her more productive and efficient. Word Processors Desktop Publishers ex. Corel, Microsoft Publisher, and Adobe Page Maker Electronic Spreadsheets ex. MS Excel, Lotus 123, and Quattro Pro Database Management ex. dBASE IV, Paradox, FoxPro, Microsoft Access, Informix, and Oracle Graphics Software ex. Harvard Graphics, Adobe Photoshop, Print Shop Deluxe, Paint Shop Pro to Adobe After Effects, Macromedia Director, and Strata Studio Pro

USER INTERFACE A software provides a user environment, which can either be: 1. command line interface – allows the user to issue commands by typing them 2. graphical user interface (GUI) – features icons or symbols that are mouse-clickable