This document discusses different types of computer memory. It begins by defining memory as the physical devices used to temporarily or permanently store programs and data for use in a computer. It then describes the main types of memory as main memory, which temporarily stores currently executing data and instructions (e.g. RAM), and secondary memory, which permanently stores data for later use (e.g. hard disks). The document goes on to provide details on different technologies used for RAM, ROM, cache memory, and storage devices.

2. In computing memory refers to the
physical devices used to store
programs (sequences of
instructions) or data (e.g. program
state information) on a temporary
or permanent basis for use in a
computer or other digital electronic
device. In the simple word Memory
is a chip which is used to store data
and instruction for the future use.

4.  Main memory is divided into two parts :Main
memory is a primary memory which is used
to store data and instruction temporarily and
it store those data and instruction which are
currently executed. For example RAM.
 Random Access memory (RAM), should be
better known as Read Write Memory (RWM).
 Read Only Memory (ROM) .

5.  A RAM memory chip is an
integrated circuit (IC)
made of millions of
transistors and capacitors.
In the most common form
of computer memory,
dynamic random access
memory (DRAM), a
transistor and a capacitor
are combines to create a
memory cell, which
represents a single bit of
data.

6.  STATIC RAM
 Semi conductor memory
 Uses flip flop to store each bit of memory so
does not need to be periodically refreshed
 Fast and consumes low power
 Expensive and has complex structure(6
transistors) so not used for high capacity
applications

7.  DYNAMIC RAM
 Stores each bit of memory in capacitor in an
intrgrated circuit
 Real capacitors leak charge so capacitors
need to be refreshed periodically
 Simple structure (1 capacitor and 1 transistor
per bit) so it has very high density

8.  New contents cannot be
added
 Used to store the
instructions of routine
type,permanent in
nature and used to
control or supervise the
hardware

9.  PROGRAMMABLE
READ ONLY MEMORY
(PROM)
 Programmed to record
the information using a
facility PROM –
programmmer
 Once the information is
recorded it cannot be
changed

10.  ERASABLE PROGRAMMABLE
READ ONLY MEMORY (EPROM)
 Information can be erased and
chip can be reprogrammed to
record different information using
PROM programmer
 In formation is erased using UV
radiations
 It is of two types- Ultra Voilet
Erasable Programmable Read
Only Memory (UEPROM) and
Electrically Alterable
Programmable Read Only Memory
(EAPROM)

11.  ELECTRICALLY
ERASABLE
PROGRAMMABLE
READ ONLY MEMORY
(EEPROM)
 Memory is erased by
electrical signals
 Provides easy means
to store temporary or
permanent information
in the form of ROM
memory

12.  Faster and expensive than
RAM
 It improves the computer’s
performance and is less
than 512 KB
 Processor can use it to
store frequently accessed
data and programs
instructions
 It is of two types – L1 /
primary cache(inside
microprocessor) and L2/
secondary cache(in the
mother board or near the
microprocessor)

13.  It supplements the
main memory. It is
permanent memory.
 Programs, data
entered into the
system, intermediate
results and final results
produced are stored in
the secondary memory

14.  MAGNETIC BASED
STORAGE
DEVICES
 Prepared using
using formatting
 Data is recorded on
disk in concentric
circular bands
called tracks.
 MAGNETIC TAPE
 FLOPPY DISK
 HARD DISK

15.  OPTICAL STORAGE
MEDIA
 Stores large amount of
data in some formats as
much as the entire hard
disk
 Reads data by focusing a
laser- generated beam of
light on light on disc’s
surface
 CD- ROM discs
 DVD- ROM discs

16.  Ranking of computer
memory devices, with
devices having the
fastest access time at
the top of hierarchy,
and devices with
slower access time
but larger capacity
and lower cost at
lower levels

17. THANKS