Fundamentals of Computer Part - 2

Mentor for Bank Exams
Fundamentals of Computer Part - 2
Components of a Computer
A. Input Unit
Computer accepts data for users through these units. It converts the instruction of users to machine language.
The input devices are Keyboard, Mouse, Jaystick, OCR (Optical Character Reader), Bar Code Reader, Bio-metric Sensor, Optical disk drive, Digital Camera, Scanner, Light Pen, MICR (Magnetic Ink Character Recognition), OMR (Optical Mark Recognition), Track Ball etc.
B. Central Processing Unit
The work of data processing of the computer done this part. It is called ‘the Brain’ of a computer. There are three parts in it.
i. Arithmetic and Logic Unit (ALU):
It performs all arithmetic and logic operations. ALU has two parts – Arithmetic Section & Logic Section.
ii. Control Unit:
This unit control all the command coming from input device. Its makes the output data. The Control Unit directs the ALU to perform specific arithmetic and logical functions on the data.
iii. Memory:
Its hold the input and output resulting data. Also hold the system and application software. There are two types of memory,
Types Computer Memory
a) Internal Memory (Primary): RAM, ROM
b) External Memory (Secondary): Hard Disk, CD, DVD, Pen drive.
Permanent Memory
It is a storable non volatile memory. It keeps all the data which store here even when power is off. E.g. ROM (Read Only Memory). ROM is a non-volatile memory.
  • Can’t read.
  • Can’t be written or changed.
  • Data not lost after the power off.
Point to Remember: ROM is where all active programs and data are stored. So, that they are readily available and easily accessed by the CPU.
Temporary Memory
It holds the all active programs data and resulting data . this type of memory easily accessible by CPU. E.g. RAM (Random Access Memory). RAM is a volatile memory.
  • Can read.
  • Can be written or changed.
  • Data lost after the power off.
Point to Remember: RAM is logical then that data stored on RAM can’t be changed.
Types of ROM
There are some qualities of ROM
  • PROM- Programmable Read Only Memory
  • EPROM- Erasable Programmable Read Only Memory
  • EEPROM- Electrically Erasable Programmable Read Only Memory (EEPROM is used for erasing & reconstructing the contents of ROM)
Types of RAM
There are some qualities of RAM.
  • DRAM- Dynamic Random Access Memory (DRAM is used for Refresh)
  • SDRAM- Synchronous Random Access Memory
  • EDORAM- Extended Data Output Random Access Memory
  • NVRAM- Non Volatile Random Access Memory
Point to Remember: Recycle Bin is a part of Hard Disk.
C. Output Unit
It displays the result of processed data to the user. E.g. VDU (Visual Display Unit), Speaker, Printer, Plotter etc.
Software is set of instructions that maintains and directs the computer to perform and process the input information. There are three type of software,
A. System Software
This software directs and makes a correlation among the various hardware of a computer. E.g. Windows XP/Vista/7/8/10, Linux, Unix, MS-Dos.
B. Application Software
It is a specific program defined applications. E.g. Windows Office, Paint, Games, Tally, Corel Draw, Adobe Photoshop etc.
C. Utility Software
It is used to debug the error in software and correct the data through the editor. E.g. Antivirus, PKZIP etc.
Firmware is the technology which has the combination of both Hardware & Software. E.g. BIOS (Basic Input/Output system) Chip inside a computer.