computer base

A. DESCRIBE COMPUTER AND IT’S FUNCTION

COMPUTER   is an electronic device forstoring and processing data,typically and binary form according to the instruction given to it in a variable program. 

There are basically for basic function of computers:

1. INPUT  items external to a system (such as a process) that is transformed by the system. Example of input devices are webcam, keyboard, camera, flash disk etc

2. PROCESSING processor is a logic circuitry that responds to and process the basic instruction that drive a computer.

Functions of a processor

• Fetch
• Decode
• Execute 
• Writeback

3. OUTPUT a result produced by a computer that is internal to the system. Examples of output device are speaker, printer, webcam, monitor,projector etc

B. DESCRIBE CHARACTERISTICS OF A COMPUTER

 The characteristics of a computer that have may be them so powerful 

• ACCURANCY  computer may obtain calculation on using bug-free chip as well as the quality of the input effectively. 
• DILLIGENCE computer is delligence for determination and carefully effort it does job efficiently and take care of little details. 
• VERSALITY means a capable of performing almost any task,provided task can be reduced to a series of logical steps. 
• STORAGE CAPACITY computer

can install a large amount ofdata,storage capacity is measured inKilobytes, Megabytes Gigabytes andTerabytes.

COMPUTER PARTS

There are many parts that works together to make computer works 

1. Hardware this is physical part of the computer, including processor, memory chip, input/output devices, tapes disk, modems, cable etc.

•  CPU (central processing unit)  is the chip that interpret and execute program instruction and manage the function of input,output and storage devices. 
• Computer case contains the major components of the computer, it help protect them. 
• MONITOR is a display screen to provide output to the user. It’s where you view the information you are working on. 
• VIDEO CARD connects the computer to the monitor. 
•  KEYBOARD used to enter information into the computer and giving command. 
• MOUSE an input device operated by rolling its ball across a flat surface.The mouse is used to control the on-screen printer by clicking, double clicking or dragging objects on the screen. 
• TOUCH PAD apressure sensitive and motion; sensitive device used in place ofmouse. 
• CD ROM -DRIVE the drive that play CDs and reads data that has been stored on the CD. 
• CD (compact disk)    a type of optical storage device. 
• HARD DISK magnetic storage device in the computer. 
• RAM is a computer temporary  memory which exist as a chip on the motherboard near the  CPU. 
• PRINTER an output device that produce a hard-copy on paper. It gives information to users in a printed form. 
• 
• BAR CODE READER an output device that converts a pattern of printed bars into number that a computer can read.
•  
• SCANNER a device thatallow pictures to be placed into acomputer.
• MICROPHONE allow the user to record sound or input to their computer. 
• SPEAKER used to generate voice, music and other sounds. 
• SOUND CARD connects the speaker and microphone to the computer.
• NETWORK CARD a circuit boardthat connects the computer tothe rest of the network, usuallyusing special cable.
•  
• SOFTWARE program that tell the computer what to do. It provides instruction that the CPU will need to carry out. 

1. Disk operating system  this Software connects thehardware with the program youwant to run. 
2. Window a family of operating system developed and produced by Microsoft corp. It provide a software graphical user interface (GUI) used on IBM and compatible computers. 

COMPONENTS OF COMPUTER SYSTEM  a computer system is one that is able to take a set of inputs, process them and create a set of output. This is done using combination of hardware and software. 

 HARDWARE are physical componentsof computer . Example input devices, output devices, primary storage (memory) and secondary storage (backing store), CPU etc. 

“Note that” Input and output devices are collectively known as peripherals. 

External hardware 

• Monitor
• Printer 
• Keyboard 
• Mouse 
• Microphone 

Internal hardware

• Hard drive
• CPU
• fan
• Motherboard 
• Sound card 

 SOFTWARE are the set of instruction/program that are loaded into the memory of the computer in order to perform a task or to control the operation of the computer. 

System software 

• Operating system 
• Utilities 
• User interface 

Application software 

• Word processor 
• Web browser 
• Game apps 

INPUT DEVICE is hardware that allows data to be entered into a computer. 

Manual input

• Keyboard 
• Mouse
• Microphone 
• Scanner 

Automatic input

• Bar code reader 
• Sensor
• Magnetic stripe rea
• optical mark reader

STORAGE is hardware that allows datato be saved longterm after it has beeninputted into the computer.  Example hard drive, DVD, CD, flash memory etc. 

OUTPUT is hardware that allows datato be provided. Example monitor, printer, projector, speaker etc. 

computer system diagram 

OPERATING SYSTEM 

Operating system is a system software that manage computer hardware and software resources and provide common service for computer program. Examples of an operating system  are UNIX, MS-Dos, MS-windows 98,XP,Vista and Mac OS. 

 TYPES OF OPERATING SYSTEM

1. BATCH OPERATING SYSTEM             

The user of  batch O.S do not interact with the computer directly, each user prepare his job on an offline devices like punch card and submits it to the conputer operator. 

2. TIME SHARING OPERATINGSYSTEM.          
Is a technique that enables many people located at various terminals to use particular computer system at the same time. Also known as Multi-programming batch system. 

3.DISTRIBUTED OPERATING SYSTEM.                  Use multiple centralprocessor to server multiple real timeapplication and multiple user. Dataprocessing jobs are distributed amongthe processor accordingly to fastprocessing and less load of the hostmachine. 

4. NETWORK OPERATING SYSTEM             
Runs on a server and provides the server the capability to manage data, users, groups, security application and other networking functions. Purpose is to allow shared file and printer access. 

5.REAL TIME OPERATING SYSTEM             
Is a data processing system in the time interval required to process and respond to input is so small that it control the environment. 

• HARD REAL TIME  It guarantee the max timefor critical operations andcomplete them on time.
• SOFT REAL TIME It guarantee the max of time but noassurity of completing it in adefined time.