It is the location to store the information.
It is used to store data and instructions.
Storage Devices is the most essential elements in a computer system.
The internal storage holds the data while processing.
It can be divided into 2 parts.
They are
A. Primary memory unit
B. secondary memory unit
They are
A. Primary memory unit
B. secondary memory unit
A) Primary Memory Unit:-
Primary Memory, also known as main storage, is the area in a computer in which data is stored for quick access by the computer’s processor. It is a computer system’s volatile storage mechanism.
This includes several types of Primary Memory Unit.
1. RAM2. CACHE MEMORY
3. ROM
1. RAM:-
It is stores the data temporarily.
RAM(Random Access Memory) is the internal memory of the CPU for storing data, program and program result.
It is read/write memory which stores data until the machine is working. As soon as the machine is switched off, data is erased.
The two main types of RAM are- SRAM – Static RAM
- DRAM – Dynamic RAM
The word static indicates that the memory retains its contents as long as power is being supplied.
SRAM chips use a matrix of 6-transistors and no capacitors.
SRAM uses more chips than DRAM for the same amount of storage space, thus making the manufacturing costs higher. So SRAM is used as cache memory and has very fast access.
DRAM, unlike SRAM, must be continually refreshed in order to maintain the data.
DRAM is used for most system memory because it is cheap and small.
All DRAM's are made up of memory cells which are composed of one capacitor and one transistor.
Cache memory is a type of memory used to hold frequently used data.
Cache memory is relatively small but very fast.
Most web browsers use a cache to load regularly viewed web pages fast.
The most important type of cache memory is the CPU cache.
Once the data is stored in cache, it can be used by accessing the cached copy rather than recomputing the original data.
ROM stands for Read Only Memory.
The memory from which we can only read but cannot write on it.
This type of memory is non-volatile.
The information is stored permanently in such memories during manufacture.
ROM can be divide into three types.
Those are
a) PROM b) EPROM
c) EEPROM
PROM:-
PROM stands for Programmable read only memory.
PROM is read-only memory that can be modified only once by a user.
The user buys a blank PROM and enters the desired contents using a PROM program.
EPROM:-
EPROM stands for Erasable Programmable read only memory.
The EPROM can be erased by exposing it to ultra-violet light for a duration of up to 40 minutes.
Usually, an EPROM eraser achieves this function.
EEPROM:-
2. Pen drive
3. CD/DVD
4. Floppy
5. External Hard disk
6. Memory Cards
2. Pen drives:-
3. CD/DVD/Blue-Ray Disk:-
4. Floppy:-
5. External Hard disk:-
6. Memory cards:-
EEPROM stands for Electrically Erasable Programmable read only memory.
The EEPROM is programmed and erased electrically.
It can be erased and reprogrammed about ten thousand times.
Both erasing and programming take about 4 to 10 ms.
B) Secondary Memory Unit
This type of memory is also known as external memory or non-volatile.
It is slower than main memory.
These are used for storing data/Information permanently.
It is also called permanent memory unit.
This includes several types of Secondary Memory Unit.
1. Hard disk 2. Pen drive
3. CD/DVD
4. Floppy
5. External Hard disk
6. Memory Cards
1. Hard disk:-
A hard disk drive, hard drive or fixed disk is a data storage device used for storing and retrieving digital information using one or more rigid rapidly rotating disks coated with magnetic material.
2. Pen drives:-
STORAGE DEVICES
________________________________________________
_____________________________________________
Post a Comment