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SOS,code letters of the international distress signal. The signal is expressed in International Morse code as … — — — … (three dots, three dashes, three dots). This combination was established by the International Radiotelegraphic Convention at Berlin in 1906. The letters (SOS) do not refer to any words but were selected because they are easy to transmit. The use of Morse code for sending distress calls is now superseded by automated systems using satellite relay; the U.S. Coast Guard no longer monitors Morse code transmissions. The distress code by radiotelephony is MAY DAY, which corresponds to the French "m'aider." The signal NC, not followed by a message, also has the same meaning.
The distress signal in radiotelegraphy, consisting of the letters S, O, and S of the international Morse code.
Morse code distress signal. [World Culture: Flexner, 359]
An infamously losing text editor. Once, back in the 1960s, when a text editor was needed for the PDP-6, a hacker crufted together a quick-and-dirty "stopgap editor" to be used until a better one was written. Unfortunately, the old one was never really discarded when new ones (in particular, TECO) came along. SOS is a descendant ("Son of Stopgap") of that editor, and many PDP-10 users gained the dubious pleasure of its acquaintance. Since then other programs similar in style to SOS have been written, notably the early font editor BILOS /bye'lohs/, the Brother-In-Law Of Stopgap (the alternate expansion "Bastard Issue, Loins of Stopgap" has been proposed).
SOS(1) (Silicon On Sapphire) An MOS chip-fabrication method that places a thin layer of silicon over a sapphire substrate (base). This technique was used for earlier LSI fabrication, but not considered useful for higher-density VLSI chips. See SOI.
(2) (Systems On Silicon) A complete system on a single chip. See SoC.
(3) (System Of Systems) An umbrella term for integrating and managing multiple independent, self-contained systems as a single entity.
(4) (Server Operating System) An operating system that resides on the server.
(5) (Sophisticated Operating System) The operating system in the Apple III. See Apple III.