Computer & TechnologyNovember 2016 Our programs in San Francisco and Santa Rosa serve organization, business, government and residential buyers in the S.F. Bay Area. We make business pickups and host Collection Events.

IBM introduced the very first magnetic disk , the RAMAC , in 1955 it held 5 megabytes and rented for $three,200 per month. Magnetic disks are platters coated with iron oxide, like tape and drums. An arm with a tiny wire coil, the study/create (R/W) head, moves radially over the disk, which is divided into concentric tracks composed of little arcs, or sectors, of information. Magnetized regions of the disk generate modest currents in the coil as it passes, thereby permitting it to read” a sector similarly, a small present in the coil will induce a regional magnetic adjust in the disk, thereby writing” to a sector. The disk rotates swiftly (up to 15,000 rotations per minute), and so the … Read More