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

Labels:

Comments

Post a Comment

Popular posts from this blog

Types Of Scanners Input Device

Scanner / Optical Scanner A scanner is an input device for computer. It can scan any printed document with text as well as images. It will : Read any printed paper or picture, Convert text or images into digital form Saves this converted digital file into computer storage for later use Uses Of Optical Scanners You can scan your documents or pictures to: Store into computer memory. To save lot of effort and time because if you type the whole text on printed page, it will take effort as well as time). Show image or text on computer screen or on a multimedia projector's screen. In addition, you can send this scanned document or image to your friends all over the world with the help of Internet & Email. You can publish the scanned documents or images on your website or blog. You can apply online and send the scanned images of your academic documents in any part of the world within minutes. If your scanner supports OCR - Optical Character Recognition, you can scan a page...
1 comment
Read more

Explain Different Types Of Output Devices

Output devices Out put devices are used to display results of processing to the user. They perform the following functions:  Receive results from memory  Convert data into human readable form  Display results to the user Examples include: Monitor, printer, plotter, speaker, and multimedia projector. Different Types of Output Devices 1.    Monitor LCD Monitor CTR Monitor     Monitor is the most commonly used output device used to display results of processing. It has a TV like shape. Pictures on monitor are formed with picture elements called PIXEL. Monitors may be Monochrome that will display results in Black & White. Color Monitors are also available. They display results in multi colors. Monitor produces soft copy output. 2.    Printers Printers are used to produce hard copy out put. They print processing results on paper. Printers are divided into two main categories: · ...
1 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