Skip to main content

What is ROM Explain Different Types of ROM

Topic: What is ROM Explain Different Types of ROM

ROM


ROM stands for Read Only Memory, because its contents can be read and used only and we cannot change or delete its contents. It is a non volatile memory. Its retains its contents even after switching off the computer. Therefore, ROM does not require electricity to retain its contents. ROM is a permanent memory. The instructions in ROM are written at the time of manufacturing by the manufacturer.  

Importance of ROM in Computer System


1. One important reason a computer needs ROM is that instructions stored in ROM (called ROM BIOS - Basic Input/Output System)execute on start-up of computer and guide the computer what to do. They make the computer ready for work.
2. ROM contains a set of start-up instructions to check that memory is functioning well and check for other hardware devices.
3. These instructions also check for an operating system and load its necessary part into RAM, so that a user interface for example "Windows Desktop" is displayed on computer screen. Now computer is ready to work with. A user now can easily perform work on computer.

Where ROM Chip is installed in Computer?


ROM chip is fixed on motherboard as shown in the figure: AMIBIOS -American Megatrends ROM chip.
Where ROM Chip is installed in Computer?
Another picture of Rom



Types of ROM


Following are the types of ROM

  • PROM

PROM stands for Programmable Read Only Memory. Instructions can be stored in PROM only once. Then it becomes ROM and we cannot change instructions in it. Initially PROM is a blank chip. Once instructions are written on it, then it become ROM. Now we cannot change or delete the instructions. If there is any error in writing instructions then PROM chip becomes unusable.

  • EPROM

EPROM stands for Erasable Programmable Read Only Memory. Program instructions written on EPROM can be erased and changed with the help of ultra violet rays. So if once we write instruction on this chip with errors, we can erase wrong instructions and rewrite new instructions.

  • EEPROM

EPROM stands for Electrically Erasable Programmable Read Only Memory. Program instructions written on EEPROM can be erased with the help of electricity and rewritten.
Labels:

Comments

Post a Comment

Popular posts from this blog

Explain Main Difference Between System Software and Application Software

Topic: Explain Main Difference Between System Software and Application Software            Differentiate between system software and application software Before , explaining the main differences between application software and system software, let us know the definitions of Application software and System software with examples. What is System Software: System software is a set of programs to control all components of computer and to manage overall operations of computer system. Differences between System software and application software System software is used as a base to install and run all application software. Examples of system software include: Operating Systems, like Microsoft Windows, DOS, Unix and Linux Device Drivers like Device driver software of a Printer (found on CD normally provided with the printer) Utility Programs like AVAST anti virus, Disk Scanners and File Viewers etc. What is Applicat...
10 comments
Read more

Definition and History of ECommerce

What do you mean by E-Commerce? Electronic Commerce (e-Commerce) is a general concept covering any form of business transaction or information exchange executed using information and communication technologies (ICTs). e-Commerce takes place between companies, between companies and their customers, or between companies and public administrations. Electronic Commerce includes electronic trading of goods, services and electronic material. BRIEF HISTORY OF E-COMMERCE + E-commerce started in early 1970’s with invention of electronic fund transfer(EFT). + Only used by large organizations, financial institutions and a few small business at that time. + After invention of EDI (Electronic Data Interchange) from financial institutions to manufacturers retailers, services and so on. + Many other e-commerce applications started from stock trading to travel reservation system. + With commercialization of internet in early 1990’s. The term electronic commerce was used. Interne...
Post a Comment
Read more

Explain different types of storage devices

Topic: Explain different types of storage devices in Computer systems Storage Devices Storage devices are used to store data and instructions permanently. Storage devices are also called secondary storage devices / backing storage devices / external storage devices or auxiliary storage devices. Examples of storage devices include Hard Disk, CD and DVD etc. Why Secondary Storage Devices are Used? Secondary storage devices are used because: Primary memory(RAM) is volatile and temporary. When computer is switched off, all data in ram is erased. Storage devices can store large amounts of data and instructions permanently whereas Primary memory has less capacity of storing data. Types Of Storage Devices There are three main types of storage devices:  Magnetic Tape   Magnetic Disk   Optical Disk   Flash Memory storage devices 1. Magnetic Tape Magnetic tape is the oldest storage device. It is made of plastic coated with m...
3 comments
Read more