Winn L. Rosch Hardware Bible, Sixth Edition

Solid-State Memory

To remember a single bit—whether alone or as part of a nibble, byte, word, or double-word—computer memory needs only to preserve a single state (that is, whether something is true or false, positive or negative, or a binary one or zero). Almost anything can suffice to remember a single state—whether a marble is in one pile or another, whether a dab of marzipan is eaten or molding on the shelf, whether an electrical charge is present or absent. The only need is that the memory unit has two possible states and that it will maintain itself in one of them once it is put there. Should a memory element change on its own, randomly, it would be useless because it does not preserve the information that it's supposed to keep.

Although ...