Ppt on secondary storage devices . A brief introduction on ssd.

1. Secondary storage devices
By-Ritwick
Enroll no.-03490388819

2. Secondary memory
• Secondary memory is computer memory that is non-volatile and persistent in
nature and is not directly accessed by a computer/processor. It allows a user to
store data that may be instantly and easily retrieved, transported and used by
applications and services.
• Secondary memory is also known as secondary storage.

3. Sequential Access Storage
Devices
• They refer to the method of storing or retrieving information that requires the
program to start reading at the beginning and continue until it finds the desired
data . Magnetic tape is an example of this.
• Magnetic tapes is a medium for magnetic recording, made of a thin,
magnetizable coating on a long, narrow strip of plastic film. It was developed in
Germany in 1928, based on magnetic wire recording.

4. Advantage Disadvantage
• Cheap
• Portable
• Lightweight
• Easily Destroyed
• Slow
• Less storage

5. Direct Access Storage Devices
• Dasd is a secondary storage device in which "each physical record has a discrete
location and a unique address.
• A record on a DASD can be accessed without having to read through intervening
records from the current location, whereas reading anything other than the
"next" record on tape requires skipping over intervening records, and requires a
proportionally long time to access a distant point in a medium.
• Ex-Magnetic disk

6. Magnetic Disk
• It is circular plate made of metal .
• It is coated with magnetic oxide.
• It contains series of concentric circles called as tracks.
• The disk is further divided into 8pie slices called as sectors.
• It has further 2 classification
• Hard disk and floppy disk

7. Advantage Disadvantage
• Faster access
• Portable
• High storage
• Cannot be tampered
• Security issues
• Little expensive than magnetic tape

8. Optical disk
• It is circulate plate made of plastic having a thin layer of magnetic oxide.
• It is light weight .
• Here we have a single track running from outside to inside with independent
sectors.
• To read or write the disk we use lazer techonology.

9. Advantage Disadvatage
• Faster
• Cheap
• Portable
• Can be tampered
• High maintenance

10. Different types of optical storage
devices

11. Thankyou