When two communicating terminals take turns transmitting. Each terminal displays the signal it is sending on its screen. Can be applied to any similarly-sized device. Usually requires rebooting the computer. The storage medium is one or more aluminum disks with a thin magnetizable coating and permanently sealed in a dust-proof housing.
Some companies make removable hard drives, from which the entire disk housing can be removed.
Compare firmware and software. Hayes compatible Refers to modems that use the same commands as modems manufactured by Hayes Microcomputer Products. See AT command . The part of a drive mechanism that reads and writes data onto the disk. Looks somewhat like a phonograph needle.