Magnetic Tape

1. Magnetic Tape • Magnetic tape is a medium for magnetic recording generally consisting of a thin magnetically coating on a long and narrow strip of plastic. Nearly all recording tape is of this type, whether used for recording audio or video or for computer data storage. • Devices that record and playback audio and video using magnetic tape are generally called tape recorders and video tape recorders respectively. A device that stores computer data on magnetic tape can be called a tape drive, a tape unit, or a streamer.

2. How do you add data to it? • A method for storing data onto a magnetic tape from one or more sources includes providing a first temporary storage area for temporarily holding data and a second temporary storage area for temporarily holding housekeeping information. The first temporary storage area contains a number of data holding areas of fixed size. • A quantity of data to be stored is read into the first data holding area of the first temporary storage area. Housekeeping information identifying the data held in the first data area and its location is formulated and written into the second temporary storage area. • The process is repeated until the first storage area is full or there is no more data to store. The contents of the first and second temporary storage areas are then written onto the tape as a single unit. The procedure is repeated as necessary until the tape is full or all of the data to be stored has been written onto the tape.

3. How do you read data from it? • The purpose of any magnetic tape unit is to write data on and read data from the tape used by the device. Tape is moved from a supply reel or hub to a take-up reel or hub on the magnetic tape transport section of the unit The magnetic oxide coated side of the tape passes in close proximity of  a read/write

4. When do you use it? • This is a backup method typically used in server/client environment. At the best of usage, it was far more expensive to buy a new hard drive for backup purposes, and would take multiple floppy disks to backup a network (Not to mention a ton of time) Magnetic tape storage offers relatively quick back up speed.

5. Is it serial or direct access? • Serial access is similar to playing an audio cassette tape. It is not so easy to jump to any track on the tape. However they are good if you want to listen to every track in order. • It is a serial access because all the information which has been organized or presented for analysis is stored on magnetic tape • Advantages of serial access systems • can be done automatically at times when the computers would not normally be used, eg overnight • easily backed up by keeping copies of tapes • magnetic tape is a cheap storage medium • Disadvantages of serial access systems • cannot be used where a fast response is needed

6. Is it solid state or does it have moving parts? • It have some moving parts and some of it are solid • EG : Moving part Solid part

7. How long will it last in years? • The most commonly given figure for the archival life of magnetic tape is 30 years. Even in a period of time of heightened concern about rules and request and records keeping, that is long enough to make storage administrators comfortable.

8. How much does it cost? • Magnetic Tape cost about $77.11

9. How much does it cost per megabyte? • $26