Introduction to Computer

IS/CSE/IT 111 Introduction to Computer

What is Computer?
Computer is a device that performs mathematical and logical operations based on the database with a minimal human interpretation.
It is a device that accepts data, processes and store these, and produces a result/output.

Four Basic Functions
1.Input
2.Process
3.Storage
4.Output

Typically, a computer system consists:
1.Input Devices – which allows the users to input data for processing
2.Storage Devices – where the processed information are stored
3.Central Processing Unit – which interprets and executes data or instruction
4.Output Devices – where outcomes are displayed

Three Main Elements of Computer System
1.HARDWARE – refers to the physical components of a computer that you can actually touch, such as keyboard, monitor, central processing unit, mouse and printer.
HARDWARE may be classified into:

1. Input Devices – these are external devices that provide information and instruction to the computer.
Common Example: Keyboard,Touch tone device, mouse, joystick, touch screen, light pen, scanning device, Fax Machine, phone card, digital cameras, sensor
2. Output Devices – these are devices that will communicate the result of processing back to the user by converting electrical signals from the Arithmetic/Logic Unit. Output devices that will produce result/output.
Common Example: monitors, Printer, Plotter, speakers
3. Central Processing Unit (CPU) – performs arithmetic and logical operations on data taken from the primary storage or on information entered through any input devices.

Five basic component of CPU:
1. Main Storage – also called memory/primary storage where instructions and data are stored while processing is done.
Two types of memory inside the main storage:
Random Access Memory (RAM) uses to store given instructions which can later be changed or erased. When data are loaded from the RAM it means WRITING data, when data are accessed it means READING data.
All information stored in it are lost or erased when the computer power is turned off or interrupted. This kind of memory is volatile.
Read Only Memory (ROM) contains stored instructions that a computer requires to be able to do its basic routine operations. The instructions still hold even when there is power interruption or shut-off. This kind of memory are non-volatile. It has a data built in by the manufacturer.
2. REGISTERS – part of the CPU that function as fast-accessed temporary memory locations. The bits of information taken from the main memory and those that will be placed in the main memory are temporarily held in the registers while computation are being performed.
3. BUSES – are bundles of tiny wires that serve as the communication path between components of the CPU. The Three most important buses are the Address, Data and Control Buses.
4. Arithmetic Logic Unit (ALU) – performs all the arithmetic and logical calculations of the CPU.
5. CONTROL UNIT (CU) – is responsible for directing the flow of instructions and data within the CPU. It fetches the instructions from the main memory for execution in the CPU. Aside from controlling the input and output devices, it also passes data to the ALU for computation.
4. SECONDARY STORAGE – where data are stored permanently.
Common example hard disk, optical disk (compact disk read only memory (CD), digital versatile disk (DVD)

Two Classes of Secondary Storage:
1. Direct Access Media – (floppy disk, flash memory(usb)) supports sequential of random access where data can be accessed directly)
2. Sequential Access Media – where data are accessed in a specific order. (magnetic tape – traditional medium for long term storage but slowest in terms of retrieval of data)

2.SOFTWARE – is untouchable. It is a set of instructions used to direct the hardware on how to turn data into useful information for people to use.
A set of instructions or program that tells the computer how to do a specific task.

Two types of Software:

1.SYSTEM SOFTWARE – refers to computer programs of library files whose purpose is to help run the computer system.
Example – Operating System (manage the whole operation of the computer), output devices (provides interface to the hardware) Utility Programs (who manage files), Compilers and interpreters (programs that will translate high-level language programs into object code)

2.APPLICATION SOFTWARE – performs specific functions, which make daily activities easier and facilitate the performance of work efficiently and effectively.

Categories of Application Software:

1.Productivity Tools – eg. Software like Word Processing, Spreadsheet, Database, Presentation Graphics, Personal Information Manager Software and Project Management.
2.Graphics and Multimedia –eg. Software like Computer-Aided Design, Desktop Publishing, Web Page Design, Image Editing, Video/Audio Editing, Multimedia Authoring
3.Home, Personal and Educational Use – eg. Software like Integrated software, Personal Finance software, Clip Art/Image Gallery, Legal Software, Educational Software, Entertainment Software.
4.Communications – eg. Software like E-mail Software, Web Browser, Chat client Software, Newsreader Software, Instant Messenger software, Groupware software, Videoconference software.

Three basic types of application software:
1.COMMERCIAL – comes prepackage and is available from software vendors. It must be purchased.
2.SHAREWARE – are software develop a d released as demonstration versions of their commercial product. Each demonstration copy has an expiration date which gives the user ample time to evaluate and decide whether the purchase the product or not.
3.OPEN SOURCE – software that is created by generous programmers and released to the public domain for free and for public use.

3.PEOPLEWARE – who use the computer system, they are the most important factor in a computer system because they manipulate and program the computer system to make it useful.
- The skilled workers in the Information Technology field.
The major compositions of IT Professionals:
1.Management Group – eg. Computer System Manager
2.Systems and Procedures Group – Computer Scientist, Computer Engineer, System Analyst
3.Programming Group – Computer Programmer
4.Computer Operations Group - Computer Operator, Data Encoder, Data Entry Operator, Computer Librarian

CAPABILITIES OF COMPUTER
1.Computer can do repetitive and routine work.
2.Computer can process large amount of data.
3.Computers are reliable and accurate.
4.Computer can store and retrieve large amount of information.
5.Computers have a self-checking ability.
6.Computer can be self-operating.
7.Computers can do remote processing.

LIMITATIONS OF COMPUTER
1.Computers are dependent on instruction and data.
2.Computers cannot generate information.
3.Computers cannot correct wrong instructions.
4.Computers cannot decide specific task. (except if they are programmed)
5.Computers are vulnerable to a virus attack.

Assignment: Note Book (Reference: Introduction to Information Technology by Albano-Atole and other computer books or use Internet)
1.Classifications Computers
2.History of Computing (from 2000 B.C. to present)