A basic characteristic of a digital system is that many hardware components of the system are able to store and/or transfer binary data. Since a two-state element is needed to represent a binary digit (bit), this type of digital hardware should physically possess the two-state characteristic. Briefly state the two physical states associated with elements in the following types of hardware:
(a) TTL circuit,
(b) nonvolatile MOSFET memory,
(c) magnetic bubble memory,
(d) optical fiber,
(e) CCD (charge-coupled device),
(f) computer hard disk,
(g) EAROM (electrically alterable read-only memory).