2. Computer Memory is used to store data and information and
instruction . It is data storage unit where data is to be processed
and instruction required for processing is stored
. Memory is the electronic holding place for the instruction and
helps in storing both input and output of the instruction .
COMPUTERMEMORY
4. PRIMARY
MEMORY
Primary memory holds only those data and
instructions on which the computer is currently
working. It hasa limited capacity and data is lost
when power is switched off that is it is volatile
memory It is generally made up of semiconductor
device. The data and instruction required to be
processed resides in the main
memory
6. RandomAccessMemory is avolatile
memory that is it stores the information
based on the power supply
, if the power supply fails / interrupted
/ stopped all the information and data
will be lost . It is used for booting or
start up of the computer . Thedata is
temporarily stored which has to be
executed by the processor .
RAM is of two types –
● SRAM (Static RAM )
● DRAM (Dynamic RAM)
RAM (RANDOM ACCESS
MEMORY)
7. ROM (READ ONLY
MEMORY)
Read Only Memory is non- volatile memory
that is it stores the memory even when the
power supply is failed/ interrupted /
stopped .it is used to store the information
that is used to operate the systemThe
information stored in the ROM in binary
format. It is also known as
permanent memory
8. TYPESOF ROM (READ ONLY MEMORY)
● MROM (Masked ROM)- These are hard-wired devices that contained apre-
programmed set of data or instructions. These kind of ROMs are known as
masked ROMs, which are inexpensive.
● PROM (Programmable Read Only Memory)- The user buys a blank PROMand
enters the desired contents using a PROM program. It can be programmed only
once and is not erasable.
9. ● EPROM (Erasable and Programmable Read Only Memory)- it is an
extension of PROM . It can be erased by exposing it to ultra-violet light
for a duration of up to 40 minutes.
● EEPROM(Electrically Erasable and Programmable ReadOnly Memory)-
EEPROM is programmed and erased electrically. It can be erased and
reprogrammed about ten thousand times. In EEPROM, any location can be
selectively erased and programmed.
10. SECONDARY
MEMORY
Secondary Memory is also known auxiliary
memory or backup memory. Secondary memory is
used to store data and programs that can be
accessed or retrieved even after the computer is
turned off. It is persistent and not immediately
accessible by acomputer or processor until
received by the main memory .
11. FEW TYPES OF SECONDARY MEMORY
● Magnetic Tape memory : In magnetic tape only one side of the ribbon is used for
storing data. It is sequential memory which contains thin plastic ribbon to store
data.
● DVD is a disc that can store a significant amount more data than a standard
compact disc. DVDs are widely used for storing and viewing movies and
other data
12. • FLOPPY DISKS - It is a hardware device that reads data
storage information FDDs are used for reading and writing on
removable floppy discs. Floppy disks are now outdated, and
have been replaced by other storage devices such as USB
• USB FLASH s a data storage device that includes flash
memory with an integrated USB interface. It is typically
removable, rewritable and much smaller than an optical disc.
