ROM

ROM :

Computer ROM

·         

      ROM stands for Read Only Memory.

·        Read Only means that the Program and data can only be read from it. Therefore Program and data cannot be written to it.

·        Most Computer contain small amount of ROM to stores programs that enable the computer to boots.

·        It is a non- volatile memory and hence it is referred as a permanent data storage area.

·        Read-only memory (ROM) is a class of storage medium used in computers  
     and other electronic devices.

·        Data stored in ROM cannot be modified, or can be modified only slowly or
     with difficulty, so it is mainly used to distribute firmware

Types of ROM:-

1. Programmable ROM (P-ROM)

·        A P-Rom is a non-volatile memory, it store the program or data permanently.

·        It uses high voltages to permanently destroy or create internal links within the chip.

·        Data can only be written once to the Programmable ROM.

2. Erasable Programmable ROM (EP-ROM)

·        EPROM can be erased by exposure to strong ultraviolet light (typically for 10 minutes or longer).

·        Once the EP-ROM is erased successfully it can be rewritten with a process that again needs higher than usual voltage applied.

3. Electrically Erasable Programmable ROM (EEP-ROM)

·        EEPROM is based on a similar semiconductor structure to EPROM, but allows its entire contents to be electrically erased, and then rewritten electrically, so that they need not be removed from the computer (or camera, MP3 player, etc.).

·        Writing or flashing an EEPROM is much slower (milliseconds per bit) than reading from a ROM or writing to a RAM (nanoseconds in both cases).

BIOS CHIP or BIOS IC

·        It is a type of computer and Laptop ROM.

·        BIOS is a chip located on all motherboard that contain instruction and setup for how your system should boot and how it operate.

·        The BIOS include instruction on how to load basic computer hardware & include a test referred as a POST that verifies the computer needs requirement to boot up properly.

·        If the computer does not pass the POST, you will receive a combination of beep indication what is malfunctioning within the computer.

POST:

·        POST is a test the computer must complete to verify all hardware is working properly before starting the remainder of the boot process.

·        If the computer passes the POST the computer will often return a single beep and if unsuccessful will create a beep code that indicates the error.

Mobile ROM

·        Mobile ROMs are the low level programming (also often called firmware) that contain the operating system and basic applications to make your phone work.

·        This type of memory keeps the saved data even if the device power is off.

·        The ROM forms a part of your internal storage and that part is not Accessible for users to write on and is thus referred to as Read Only Memory.

·        This ROM part of your internal storage is where your Android operating system resides.

·        Also OEM’s add some preinstalled apps in this memory sections which cannot be deleted on users end either.

·        This is the reason why you don’t get full internal memory as advertised on the Box, because a part of it has been used to house O.S. and preinstalled apps.

·        The rest of the internal storage will be used for storing and downloading Apps which will store this.