Magnetic tape

1. Magnetic tape , Magnetic Bubble & CCD By s Justin Joshua FY.IT-17

2. Magnetic Tape Magnetic tape is made of a thin magnetizable coating on a long, narrow strip of plastic . It was developed in Germany , based on magnetic wire recording . It was a key technology in early computer development . Magnetic tape can suffer from deterioration called sticky-shed syndrome .

3. A tape drive (or "transport" or "deck") uses motors to wind the tape from one reel to another, passing tape heads to read, write or erase . Magnetic tape was first used to record computer data in 1951 on the Eckert- Mauchly . The recording medium was a thin strip of one half inch wide metal . Recording density was 128 characters per inch .

4. Tape remains a viable alternative to disk in some situations due to its lower cost per bit. The highest capacity tape media are generally on the same order as the largest Tape has the benefit of a comparatively long duration during which the media can be guaranteed to retain the data stored on the media.

5. Magnetic bubble The memory device is formed by lining up tiny electromagnets at one end with detectors at the other end. Bubbles written would be slowly pushed, forming a sheet of Twistors lined up beside each other. The output from the detector back to the electromagnets turns the sheet into a series of loops, which can hold the information as long as needed.

6. Bubble memory is a non-volatile memory . Even when power was removed, the bubbles remained, just as the patterns do on the surface of a disk drive . The field that pushed the bubbles along the surface was generated electrically, whereas disk drives required mechanical movement.

7. Because of the small size of the bubbles, the density was in theory much higher than existing magnetic storage devices. The bubbles had to cycle to the far end of the sheet before they could be read.

8. CCD Charged coupled device ( ccd ) CCD is a device for the movement of electrical charge, within the device to an area where the charge can be manipulated . The CCD is a major technology for digital imaging . In a CCD image sensor , pixels are represented by p-doped MOS capacitors.

9. The charge-coupled device was invented in 1969 at AT&T Bell Labs by Willard Boyle and George E. Smith . The first working CCD made with integrated circuit technology was a simple 8-bit shift register. The charge packets (electrons, blue) are collected in potential wells (yellow) created by applying positive voltage at the gate electrodes (G). Applying positive voltage to the gate electrode in the correct sequence transfers the charge packets.

10. In a CCD for capturing images, there is a photoactive region and a transmission region made out of a shift register .