Q1 LESSON 6 - HARDWARE AND SOFTWARE

COMPUTER

    An electronic device operating under the control of instruction stored in its own memory that can accept data (input), process the data according to specified rules, produce information (output), and store the information for future use.  

FUNCTIONALITIES OF A COMPUTER

Any digital computer carries out five functions in gross terms:

• Takes data as input.
• Store the data/instructions in its memory and use them when required.
• Processes the data and convert it into useful information.
• Generates the output.
• Controls all the above four steps.
  
  
  

COMPUTER COMPONENTS

Any kind of computers of Hardware and Software.

HARDWARE

    The collection of physical elements that contributes a computer system. Computer hardware refers to the physical parts of components of a computer such as the mouse, monitors, keyboards, computer storage, hard drive disk (HDD), and etc. all of which are physical object that can be touched.

 

INPUT DEVICES

    Any peripheral piece of computer hardware equipment to provide data and control signals to an information processing system such as computer or other information appliance. Input devices translate data from form that humans understand to one that the computer can work with. Most common are keyboard and mouse.

EXAMPLE OF INPUT DEVICES

• Keyboard
• Mouse
• Joystick
• Microphone
• Numeric Keyboard
• Touch Screen
• Digital Camera
• Scanner
• Webcams
• Remote Control
• Graphics Table

Note: The most common used keyboard is the QWERTY keyboard. Generally standard keyboard has 104 keys.

CENTRAL PROCESSING UNIT (CPU)

    The brain of the computer. It is responsible for all functions and processes. Regarding computer power, the CPU is the most important elements of a computer system. CPU is composed of three main parts:

1. ARITHMETIC LOGIC UNIT (LGU)- executes all arithmetic and logical operations. Arithmetic calculations like as addition, subtraction, multiplication, and division. Logic operation like compare numbers, letters, or special characters.
2. CONTROL UNIT (CU)- controls and co-ordinates computer components.
3. REGISTERS- stores the data that is to be executed next very fast storage area.

PRIMARY MEMORY

1. RAM (RANDOM ACCESS MEMORY)- memory scheme within the computer system responsible for storing on a temporary basis, so that it can be promptly accessed by the processor as and when needed. It is a volatile in nature, which means that data will be erased once supply to the storage device is turned off.
2. ROM (READ ONLY MEMORY- a permanent form of storage. ROM stays active regardless of whether power supply is turned on or off. ROM devices do not allow data stored on them to be modified.

SECONDARY MEMORY

1. HARD DISK DRIVE (HDD)- a part of a unit often called a "disk drive", that store and provides relatively quick access to large amount of data on an electromagnetically charged surface or set of surfaces.
2. OPTICAL DISK- an Optical Disk Drive (ODD) is a disk drive that uses laser light as part of the process of reading or writing data to or from optical discs. Compact discs, DVDs, and Blu-ray are common types of optical media which can be read and recorded by such drives.
3. FLASH DISK - storage module made of flash memory chips. A flash disks have no mechanical platters or access arms, but the term "disk" is used because the data are accessed as if they were on a hard drive. The disk storage structure is emulated.

COMPARISON BETWEEN MAIN MEMORY (RAM) AND SECONDARY MEMORY

        RAM 

• Memory
• Smaller amount (typically 500MB - 6GB)
• Temporary storage of file
• Like real desktop has only current work
• Content disappears when you turn off pone, consist of chips (microprocessors) a temporary copy is put into RAM. 

HARD DISK (HARD DRIVE) 

• Storage 
• Larger amount (80GB to 1000GB)
• Permanent storage of file
• Like file cabinet - has long term storage
• Contents remain when you turn off consist of hard disks (platter) holds the original copy

OUTPUT DEVICES

-An output device is any piece of computer hardware equipment used to communicate the result of data processing carried out by an information processing system (such as a computer) which converts the electronically generated information into human readable form.

 EXAMPLE OF OUTPUT DEVICES

• CRT Monitor 
• Dot Matrix Printer
• Plotters
• TFT Monitor
• Laser Printer
• Speaker 
• Multimedia Projectors
• Inkjet Printer

EXAMPLES ON OUTPUT DEVICES 

1. Monitor
2. LCD Projection Panels 
3. Printer (all types)
4. Computer output microfilm (COM)
5. Plotters 
6. Speakers
7. Projector

 BASIC TYPES OF MONITORS ARE:

• Cathode Ray Tube
• Liquid Crystal Display (LCD)
• Light - emitting diode (LED)

PRINTER TYPES

1. Laser Printer
2. Ink Jet Printer
3. Dot Matrix Printer

SOFTWARE 

-a generic term for organized collections of computer data and instruction, often broken into two major categories system software that provides the basic non-task specific function of the computer, and application software which is used by users to accomplish specific tasks. 

SOFTWARE TYPES

SYSTEM SOFTWARE

- responsible for controlling, integrating, and managing the individual hardware components of a computer system so that other software and the users of the system see it as a functional unit without having to be concerned with the low-level details such as transferring data from memory to disk, or rendering text onto a display.

- Generally, system software consists of an operating system and some fundamental utilities such as disk form alters file manager, display managers, text editors, user authentication (login) and management tools, and networking and device control software. 

APPLICATION SOFTWARE 

- used to accomplish specific tasks other than just running the computer system. 

- Application software may consist of a single program, such as an image viewer, a small collection of programs (often called a software package) that work closely together to accomplish a task, such as a spreadsheet or text processing system, a larger collection (often called a software suite) of related but independent programs and packages that have a common user interface or shared data format.

UNIT OF MEASUREMENTS

• STORAGE MEASUREMENTS- basic unit in computer data storage is called a "bit". Computers use these little bits, which are composed of ones and zeros (1 and 0), to do things and talk to other computers. This two numbers system is called a "binary number system" since it has only two numbers in it. The decimal number system in contrast has ten unique digits zeros through nine.
  
  
  
• SPEED MEASUREMENTS- the speed of Central Processing Unit (CPU) is measured by Hertz (Hz), which represent a CPU is known a computer speed.

  

  
  

COMPUTER CLASSIFICATION

    Computers can be generally classified by size and power as follows, through there is considerable overlap.

1. PERSONAL COMPUTER- a small, single-user computer based on a microprocessor. In addition to the microprocessor, a personal computer has a keyboard for entering data, a monitor for displaying information and a storage device for saving data.
2. WORKSTATION- a powerful, single-user computer. A workstation is like a personal computer, but it has a more powerful microprocessor and a higher-quality monitor.
3. MINICOMPUTER- a multi-user computer capable of supporting from 10 to hundreds of users simultaneously.
4. MAINFRAME- a powerful multi-user computer capable of supporting many hundreds or thousands of users simultaneously.
5. SUPERCOMPUTER- an extremely fast computer that can perform hundreds of millions of instructions per sound.

LAPTOP AND SMARTPHONE COMPUTER

1. LAPTOP- a battery or AC powered personal computer that can be easily carried and used in a variety of location.
2. NETBOOK- a type of laptop that is designed to be even more portable. They're often cheaper than laptop or desktops. They are generally less powerful than other type of computers, but they provide enough power per email and internet access, which is where the name "netbook" comes from.
3. MOBILE DEVICE- basically any handheld computer. It is designed to be extremely portable, often fitting in the palm of your hand or in your pocket. Some mobile devices are more powerful, and they allow you to do many of the same things you can do with the desktop or laptop computer.
4. TABLET COMPUTER- like laptops, tablet computers are designed to be portable. However, they provide a very different computing experience. The most obvious difference is that tablet computer doesn't have keyboards or touchpads. instead, the entire screen is touch-sensitive, allowing you to type on a virtual keyboard and use your finger as a mouse pointer.
5. SMARTPHONE- a powerful mobile phone that is designed to run s variety of application in addition to phone service.                                                                                                       

 DATA, INFORMATION AND KNOWLEGDE           

1. DATA- facts and figures which relay something specific but which are not organized in any way and which provide no further information regarding patterns, context, etc.
2. INFORMATION- per data to become information, it must be contextualized categorized, calculated, and condensed. Information thus points a bigger picture, it is data with relevance and purpose.  
3. KNOWLEDGE- is closely linked to doing and implies know how and understanding.

THE CONTENT OF THE HUMAN MIND CAN BE CLASSIFIED INTO FOUR CATEGORIES

1. DATA- symbols
2. INFORMATION- data that are processed to be useful provides answers to "who" "what" "where" and when questions.
3. KNOWLEDGE- application of data and information answers "how" questions.
4. WISDOM- evaluated understanding

CHARACTERISTICS OF COMPUTER

speed accuracy, diligence, storage capability and versatility are some of the key characteristic of a computer.

1. SPEED- the computer can process data very fast, at the rate of millions of instructions per second.
2. ACCURACY- computer provide a high degree of accuracy.
3. DILIGENCE- when use for a longer period of time, the computer does not get tired or fatigue.
4. STORAGE CAPABILITY- large volumes of data  and information can be stored in the computer and also retrieved whenever required.
5. VERSATILITY- computer is versatile in nature. It can perform different types of task with the same ease.

COMPUTER VIRUSES

1. VIRUSES- a small piece of software that piggybacks on real programs for example, virus might attach itself to a program.
2. E-MAIL VIRUSES- travel us an attachment to email messages, and usually replicates itself by automatically mailing it self to dozens of people in the victims e-mail address book.
3. TROJAN HORSE- simply a computer program. The program claim to do one thing (it may claim to be a game) but instead does damage when you run it (it may erase your hard disk)
4. WORDS- a small pieces of software that uses computer network and security holes to replicate itself.