Primary memory, also known as main memory or internal memory, is directly accessible to the CPU and holds temporary data during program execution. It includes RAM, ROM, PROM, and EPROM. Secondary memory, also called external memory or auxiliary memory, provides larger storage and retains data when power is removed. Common examples are hard disks, CD-ROMs, magnetic tapes, and flash memory. Secondary memory is organized into files and directories for abstraction and includes additional metadata.

1. By
Ayush Garg

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Primary Memory
Secondary Memory
Summary
Questions & Answers
Thank You

3. Only one directly accessible to the CPU.
Used to hold the temporarily data during the execution.
Other names are – Main Memory or Internal Memory
Types of Primary memory–
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RAM – Random Access Memory
ROM – Read Only Memory
PROM/EPROM - Programmable ROM
It has a Limited Capacity
Information is retained only when it is Actively
Rehearsed.

5. s
1. Secondary Memory also known as EXTERNAL
MEMORY or AUXILIARY MEMORY.
2. Often formatted according to a File Systems Format.
3. Provide abstraction necessary to organize data into files
and directories.
4. Also Providing Additional Information METADATA
describing the owner of the certain file.

6.  Allows
Stored Data to Be Accessed Quickly In Any
Random Order
It Has Taken The Form Of Integrated Circuits
 It is Associated With Volatile Types Of Memory
 Where The Stored Data Is LOST If The Power Is
REMOVED
 Any Location In The Device Can Be Selected At Random,
Access To The Information Stored Is DIRECT

7.  A Class Of Data Storage Device
 It Reads the Data In Sequence
 Very Much In Contrast With RAM (where Data Can Be
Accessed In Any Order)
 They Are Usually A Form Of Magnetic Devices
 Access Can STILL Be Made To Arbitrary Locations
 Typically Used For Secondary Storage
 It Has High Density And Cost As Compared To RAM
 As Well As Resistance to Wear and Non-Volatility
 EXAMPLE – Hard Disks, CD- ROMS And Magnetic Tapes

8.  HARD DISKS
 PERFORMANCE ENHANCEMENTS
 OPTICAL DISKS
 SPECIALISED MEDIA
 FLOPPY DISKS

9.  Portable And Removable
 Flat Circular Mylar Media
 Magnetic Charge on Metal Oxide
Film Coating
 Standard 2 HD 1.44 MB
 Parts
 Tracks
 Sectors

10.  Floppy disk cartridges
 Zip Disks
 250 MB
 Super Disks
 120 MB
 HiFD disks
 200 MB

11.  Metallic disks
 Fast retrieval, greater capacity
 Read/write heads ride cushion of air .000001”
thick
 Three types
 Internal hard disk
 Hard-disk cartridge
 Hard-disk pack

13.  Inside system unit
 Non-removable or portable
 Great capacity
 Over 100 Gigabytes
 Fast access speed

14.  Portable, removable
 Complement internal
hard drive
 JAZ from Iomega
 SPARQ from
SyQuest
 PC Card Hard Disks
 Laptop computers

15.  Used in mainframes
 Removable
 Resemble stack of vinyl
records
 Multiple read/write heads
 Massive storage capacity
 Fast access time

16.  Improving performance of hard disks
 Disk caching
 Redundant Arrays of Inexpensive Disks (RAID)
 File compression and decompression

17.  Very large capacity
 Up to 17 gigabytes
 Use reflected light
projected by a laser
 Lands and Pits represent 1’s
and 0’s
 Formats
 Compact Disk (CD)
 Digital Versatile Disk
(DVD)
 Data Play

18.  Widely used format today
 Can store from 650 MB to 1
GB
 Rotational speed = data
transfer time
 Types of CDs
 CD-ROM
 CD-R
 CD-RW

19.  Digital Versatile Disk
 Rapidly replacing CDs
 Higher capacity
 17 times the capacity
of a CD

20.  DVD types
 DVD-ROM
 Read only memory
 DVD-R
 Recordable
 DVD-RAM or DVD-RW
 Competing rewritable formats

21.  Optical write-once format
 Similar to CD-R
 Size of a quarter
 Used for special
applications
 Storing digital
photographs
 Storing music for
portable players

22.  Sequential access
 Commonly used for backing-up data
 Very large capacity
 Types of magnetic tape
 Tape cartridges
 Magnetic tape reels

24.  Tape cartridges
 Backup tape for microcomputer
 Capacities range from 120 MB to 5 GB
 Digital audio tape (DAT)
 Tape reels
 Minicomputer and mainframe
 1/2 inch wide and 1/2 mile long
 Stores 1600 to 6400 cpi

25.  Internet hard drive
 Free or low-cost storage on the Web
 Access information from any location
 Access time is greater
 Solid-state storage
 No moving parts
 Flash memory cards

26.  Blue laser light optical
devices
 Aimed more accurately
 Can increase storage
capacity to 27 GB per
standard optical disk
 New players will likely play
both