Internal memory, referred to as primary memory, stores essential data for quick access during computer operation, including volatile types like RAM and non-volatile types like ROM. RAM is a temporary storage that allows for fast data access but loses information when powered off, while ROM retains data permanently and is used for boot instructions. Key characteristics of internal memory include limited capacity, high access speed, and cost considerations.

1. INTERNAL MEMORY
A SUMMARY OF INTERNAL MEMORY….

2. MEMORY
A memory can store a massive amount of data, such as songs, videos, documents,
files, folders, images, and software
Computer memory is used to store data and information permanently and
temporarily. This data and information can be recalled whenever a user requests or
demands.
The memory is categorized as INTERNAL and EXTERNAL memory, but we shall
focus strictly on internal memory…

3. CHARACTERISTICS OF MEMORIES
1. Volatility; Here we can talk about volatile and non volatile a memory is. examples of volatile memory is RAM
and Non-volatile such as ROM, Flash memory
2. Mutability; talks about how memory has the tendency to change..
Read/Write; RAM, HDD, SSD, RAM, Cache, Registers o
Read Only ; Optical ROM (CD/DVD…), Semiconductor ROM}
3. Accessibility; here we can talk about how information can be accessed easily without difficulty. Examples of
such memory are;
 Random Access such as; RAM, Cache
 Direct Access; HDD, Optical Disks
 Sequential Access; Magnetic Tapes

4. INTERNAL MEMORY
What are internal memory?
Internal memory, also called ‘’main or primary memory refers to memory that
stores amounts of data that can be accessed quickly while the computer is running.
The internal memory is installed inside the computer system. Internal storage stores
or hold essential system files and applications which are most important for the
computer system. Any computer software and applications are installed with the
help of internal memory, such as RAM. In Mobile devices, applications and
software are directly installed in the internal memory. The internal memory or
internal storage interacts directly with the central processing unit.

5. FEATURE OF INTERNAL MEMORY
The key features of internal memory are
1. Limited storage capacity.
2. Temporary storage.
3. Fast access.
4. High cost.

6. TYPES OF INTERNAL MEMORY
RAM (RANDOM ACCESS MEMORY)
ROM (READ-ONLY MEMORY)

7. ROM (Read Only Memory)
ROM is the long-term internal memory. ROM is “Non-Volatile Memory” that retains data without
the flow of electricity. ROM is an essential chip with permanently written data or programs. It is
similar to the RAM that is accessed by the CPU. ROM comes with pre-written by the computer
manufacturer to hold the instructions for booting-up the computer.

8. There Is Generally Three Broad Type Of ROM:
PROM (Programmable Read Only Memory)
EPROM (Erasable Programmable Read Only
Memory)
EEPROM (Electrically Erasable Programmable
Read Only Memory):

9. PROM (Programmable Read Only Memory)
PROM stands for programmable ROM. It can be programmed only be
done once and read many. Unlike RAM, PROMs retain their contents
without the flow of electricity. PROM is also nonvolatile memory. The
significant difference between a ROM and a PROM is that a ROM
comes with pre-written by the computer manufacturer whereas PROM
manufactured as blank memory. PROM can be programmed by PROM
burner and by blowing internal fuses permanently.

10. PROM(Programmable Read Only Memory)

11. EPROM (Erasable Programmable Read Only Memory)
EPROM is pronounced ee-prom. This memory type retains its contents until it exposed to intense
ultraviolet light that clears its contents, making it possible to reprogram the memory

12. EEPROM (Electrically Erasable
Programmable Read Only Memory):
(Electrically Erasable Programmable Read Only Memory): EEPROM can be
burned (programmed) and erased by first electrical waves in a millisecond. A single
byte of a data or the entire contents of device can be erased. To write or erase this
memory type, you need a device called a PROM burner.

13. RAM (Random ACCES MEMORY)
The Word “RAM” stands for “random access memory” or may also refer to short
term memory. It’s called “random” because you can read store data randomly at any
time and from any physical location. It is a temporal storage memory. RAM is
volatile that only retains all the data as long as the computer powered. It is the
fastest type of memory. RAM stores the currently processed data from the CPU and
sends them to the graphics unit.

14. Characteristics of RAM:
Possible to read/write easily and rapidly
 Volatile
 Exists in two forms, static or dynamic

15. Types of RAM [Random Access
Memory]
Static RAM (SRAM)
Dynamic RAM (DRAM)
Synchronous Dynamic RAM (SDRAM)

16. Static RAM (SRAM):
Static RAM is the form of RAM and made with flip-flops and used for primary storage are
volatile. It retains data in latch as long as the computer powered. SRAM is more expensive and
consumes more power than DRAM. It used as Cache Memory in a computer system. As
technically, SRAM uses more transistors as compared to DRAM. It is faster compared to DRAM
due to the latching arrangement, and they use 6 transistors per data bit as compared to DRAM,
which uses one transistor per bit.

17. Dynamic Random Access Memory
(DRAM):
It is another form of RAM used as Main Memory, its retains information in
Capacitors for a short period (a few milliseconds) even though the computer
powered. The Data is Refreshed Periodically to maintain in it. The DRAM is
cheaper, but it can store much more information. Moreover, it is also slower and
consumes less power than SRAM.

18. Types of DRAM
 Asynchronous DRAM
 Fast Page Mode (FPM) DRAM or FPRAM
 Extended Data Out (EDO) DRAM
 Burst EDO (BEDO) DRAM
 Synchronous Dynamic RAM (SDRAM)
 Direct Rambus DRAM (DRDRAM)
 Double Data Rate (DDR) SDRAM

19. Synchronous Dynamic RAM (SDRAM)
Is a term that is used to describe dynamic random access memory that has a
synchronous interface. Traditionally, dynamic random access memory (DRAM) has
an asynchronous interface which means that it responds as quickly as possible to
changes in control inputs. SDRAM has a synchronous interface, meaning that it
waits for a clock signal before responding to control inputs and is therefore
synchronized with the computer's system bus. The clock is used to drive an internal
finite state machine that pipelines incoming instructions. This allows the chip to
have a more complex pattern of operation than asynchronous DRAM which does
not have a synchronized interface.

20. Synchronous Dynamic RAM (SDRAM)

21. DIFFERENCE BETWEEN ROM AND RAM
ROM;
 if the Central Processing Unit (CPU) needs to access the data on ROM, first the
data must be transferred to RAM, and then the Central Processing Unit (CPU)
will be able to access the data. WHILE
 Data present in Read Only Memory (ROM) is not volatile, it is permanent. Data
will remain unchanged even when there is disruption in .power supply.
 The data stored in ROM is used to bootstrap the computer.
 Data in ROM can only be read, it cannot be modified or erased

22. DIFFERENCE BETWEEN ROM AND RAM
RAM;
 Data stored on RAM can be accessed by the Central Processing Unit
 Data of RAM is very volatile, it will exist as long as there is no interruption in
power.
 The data stored in RAM is used by Central Processing Unit (CPU) to process
current instructions
 Data in RAM can be modified, erased or read.