MEMORY Computer memory refers to the hardware device that are used to store

and access data or programs on a temporary or permanent basis.

There are TWO TYPE of nature of memory in a computer.

Temporary/ Volatile

Permanent / Nonvolatile

PRIMARY MEMORY

It is computer memory that a processor or computer accesses first or

directly.

NOTE

Primary memory also known as main memory.

Secondary Memory also known as Auxiliary memory or Non Volatile Memory.

RAM (RANDOM ACCESS MEMORY)

When you power off your computer the data stored in RAM is deleted,

means volatile in nature.

Static RAM (Static Random Access Memory)

It is called static because it will continue to hold information without

refreshment. SRAM use 28 pin system.

Dynamic RAM

It requires refreshment. Example of dynamic ram are DDR1, DDR2 ,DDR3,

DDR4.

VRAM

Video RAM, also known as multiport dynamic random access

memory (MPDRAM), is a type of RAM used specifically for video

adapters or 3-D accelerators.

Cache memory

A cache used by the CPU to reduce the average time to access memory.It

is used in between the main memory and CPU.

ROM (Read Only Memory)

ROM is also a type of non-volatile storage which is located on the

motherboard that contains the basic instructions for what needs to

happen when a computer is powered on.

PROM

Programmable read-only memory (PROM) is read-only memory ( ROM ) that can be modified once by a user.

EPROM

Acronym for erasable programmable read-only memory, EPROM is a special type of memory that retains its contents until it is exposed to ultraviolet light.

EEPROM

Short for electrically erasable programmable read-only memory. EEPROM is a special type of PROM that can be erased by exposing it to an electrical charge.

SECONDARY STORAGE

It is used to store data for backup purpose.

Types of access:

Sequential access

Direct/Random access

Magnetic Tape

It is based on sequential access.

MAGNETIC DISK

HARD DISK

It is a permanent magnetic storage device.

FLOPPY

It is known as diskette

Zip Disk

A zip disk is like a large, chunky floppy disk. It can store 750MB data.

OPTICAL DISC

Optical storage refers to the storage of data on an optically readable medium by laser beam.

CD (COMPACT DISC) CD is made polycarbonate plastic material and aluminium coated. CDs have a capacity of about 700MB.

DVD (Digital Versatile Disc) It is an optical disc like the CD, but with much higher capacity. DVD can store about 4.7GB.

BRD (Blue Ray Disc) Blu-ray Disc is a high-density optical disc format similar to DVD .It’s capacity is up to 50GB to 100 GB.

HVD (Holographic Versatile Disc) The Holographic Versatile Disc (HVD) is an optical disc technology It’s capacity is 6 TB.

Flash memory Flash memory is an electronic non-volatile computer. Ex Pen drive, memory card. Latest version of pen drive is 3.1 and latest version of memory card is class 10 ultra.

Disk Structures

Track The disk is divided into no. of concentric circles called tracks.

Sector Data storage are in one track multiple block is called sector

Virtual Memory

Virtual memory combines your computer’s RAM with temporary

space on your hard disk. It is also called Extended RAM.

NEW TECHNOLOGY STORAGE

DDR 4 RAM

It is a HIGH SPEED RAM developed by Samsung Its speed is 2133 to

4266 mt/s (million transfer per second) SK Hynix developed 128GB

DDR4 RAM with High speed performance DDR4 RAM used 288 pins

system.

SSD (SOLID STATE DRIVE)

Solid-state drives actually aren't hard drive in the traditional sense of

the term. It is made by semiconductor chips.

3D X point memory Intel and micron have unveiled 3D X Point a new memory technology

1000 time faster than NAND and 10 time faster conventional DRAM.

SOME QUESTIONS

Q.1Which computer memory is used for storing programs and data currently being processed by the CPU?

A) Mass memory

B) Internal memory

C) Non-volatile memory

D) PROM

E) None of these

Q.2) CD-ROM

A) Is a `semiconductor memory

B) Memory register

C) Magnetic memory

D) Optical storage

E) None of these

Q.3) A name or number used to identify a storage location is called

A) A byte

B) A record

C) An address

D) All of above

E) None of these

Q.4 The difference between memory and storage is that memory is …. And storage is …

A) Temporary, permanent

B) Permanent, temporary

C) Slow, fast

D) All of above

E) None of these

Q.5 Which of the following memories must be refreshed many times per second?

A) Static RAM B) Dynamic RAM C) EPROM D) ROM E) None of these

Q.6 Floppy disks which are made from flexible plastic material are also called? A) Hard disks B) High-density disks C) Diskettes D) Templates E) none of these

Q.7 Which of the following storage uses laser technology to store

data?

A) Tape B) hard disk C) floppy D) CD

E) none of these

Q.8 Which of the following magnetic disk is used in computer

permanently?

A) Tape B) hard disk C) floppy D) CD

E) none of these

Q.9 Virtual memory stores data in---------------?

A) Tape B) hard disk C) floppy D) CD

E) none of these

Q.10 Which of the following memory is close to CPU

A) Virtual memory B) Main memory C) Cache D) Secondary

memory E) none of these

ANSWERS

Q.1 B Q.2 D Q.3 C

Q.4 A Q.5 B Q.6 C

Q.7 D Q.8 B Q.9 B

Q.10 C

www.bankersguru.org