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The Free On-line Dictionary of Computing (foldoc)

(From the technical term "logical device", wherein a physical
device is referred to by an arbitrary "logical" name) Having
the role of. If a person (say, Les Earnest at SAIL) who had
long held a certain post left and were replaced, the
replacement would for a while be known as the "logical" Les
Earnest. (This does not imply any judgment on the
replacement).

Compare {virtual}.

At Stanford, "logical" compass directions denote a coordinate
system in which "logical north" is toward San Francisco,
"logical west" is toward the ocean, etc., even though logical
north varies between physical (true) north near San Francisco
and physical west near San Jose. (The best rule of thumb here
is that, by definition, El Camino Real always runs logical
north-and-south.) In giving directions, one might say: "To
get to Rincon Tarasco restaurant, get onto {El Camino Bignum}
going logical north." Using the word "logical" helps to
prevent the recipient from worrying about that the fact that
the sun is setting almost directly in front of him. The
concept is reinforced by North American highways which are
almost, but not quite, consistently labelled with logical
rather than physical directions.

A similar situation exists at MIT: Route 128 (famous for the
electronics industry that has grown up along it) is a
3-quarters circle surrounding Boston at a radius of 10 miles,
terminating near the coastline at each end. It would be most
precise to describe the two directions along this highway as
"clockwise" and "counterclockwise", but the road signs all say
"north" and "south", respectively. A hacker might describe
these directions as "logical north" and "logical south", to
indicate that they are conventional directions not
corresponding to the usual denotation for those words. (If
you went logical south along the entire length of route 128,
you would start out going northwest, curve around to the
south, and finish headed due east, passing along one infamous
stretch of pavement that is simultaneously route 128 south and
Interstate 93 north, and is signed as such!)

[{Jargon File}]

(1995-01-24)