A Magnetic Drum is a device that uses a rotating drum with a magnet inside to store and retrieve data. The drum is coated with a magnetic material, and the data is recorded by changing the polarity of the magnetic particles on the drum surface. The drum is connected to a read-write head, which can detect and modify the magnetic data as the drum spins. The Magnetic Drum was one of the earliest forms of computer memory, and was used in many computers from the 1950s to the 1970s. The Magnetic Drum was also used as a secondary storage device for some applications. The Magnetic Drum had several advantages, such as fast access time, high reliability, and low power consumption. However, it also had some disadvantages, such as low storage capacity, high cost, and mechanical wear. The Magnetic Drum was eventually replaced by other technologies, such as magnetic core memory and hard disk drives.
Magnetic Drum, material is fed into a rotating shell revolving around a stationary magnet. Ferrous metal remains on the shell surface until it passes through the magnetic field - separating it from the normal trajectory of the nonferrous material. Any ferrous tramp metal is captured by the magnetic field and held on the drum's surface. As the drum rotates, the metal is carried past the diverter and released outside the magnetic field.