Encyclopedia > Programmable read-only memory

  Article Content

Programmable read-only memory

A programmable read-only memory (PROM) is a memory that comes blank, usually with all bits reading as 1, and can be programmed by applying a high voltage (typically 12 to 21 volts) and writing to it. Each bit is a fuse, burning which causes it to read as 0.

Read-only means that, unlike the case with conventional memory, the programming cannot be changed (at least not by the end user).

Such PROMs are used to store programs permanently. They are frequently seen in computer games, or such products as electronic dictionaries, where PROMs for different languages can be substituted. See also Erasable programmable read-only memory, or EPROM.

All Wikipedia text is available under the terms of the GNU Free Documentation License

  Search Encyclopedia

Search over one million articles, find something about almost anything!
  Featured Article

... this overall reaction as two half-reactions: an oxidation reaction: H2 → 2H+ + 2e- and a reduction reaction: F2 + 2e- → 2F- Elements always have an ...