See also graphical user interface, Application Program Interface.
(22 May 1996)
(05 Jan 1995)
Though Apple Computer would like to claim they invented the GUI with
their Macintosh operating system, the concept
originated in the early 1970s at Xerox's PARC laboratory.
Compare command line interface.
(12 Jan 1996)
MORE
(05 Jan 1995)
An API can also provide an interface between a high level language and
lower level utilities and services which were written
without consideration for the calling conventions supported by compiled
languages. In this case, the API's main task may be the
translation of parameter lists from one format to another and the interpretation
of call-by-value and call-by-reference arguments
in one or both directions.
(15 Feb 1995)
CD-ROM is popular for distribution of large databases, software and
especially multimedia applications. The maximum
capacity is about 600 megabytes. A CD can store around 640 megabytes
of data - about 12 billion bytes per pound weight.
CD-ROM drives are rated with a speed factor relative to music CDs (1x).
12x drives are common today (April 1997). Above
12x speed, there are problems with vibration and heat. The newer constant
angular velocity (CAV) drives will give speeds up to
20x but due to the nature of CAV the actual throughput increase over
12x will be less than 20/12. 20x is thought to be the
maximum speed due to mechanical constraints.
CD-ROM drives may connect to an IDE interface, a SCSI interface or a
propritary interface, of which there are three - Sony,
Panasonic, and Mitsumi. Most CD-ROM drives can also play audio CDs.
There are several formats used for CD-ROM data, including Green Book
CD-ROM, White Book CD-ROM and Yellow
Book CD-ROM. ISO 9660 defines a standard file system.
See also Compact Disc Recordable, Digital Video Disc.
An extensive user community has developed on the Web since its public
introduction in 1991. In the early 1990s, the
developers at CERN spread word of the Web's capabilities to scientific
audiences worldwide. By September 1993, the share
of Web traffic traversing the NSFNET Internet backbone reached 75 gigabytes
per month or one percent. By July 1994 it was
one terabyte per month.
On the WWW everything (documents, menus, indices) is represented to
the user as a hypertext object in HTML format.
Hypertext links refer to other documents by their URLs. These can refer
to local or remote resources accessible via FTP,
Gopher, Telnet or news, as well as those available via the http protocol
used to transfer hypertext documents.
The client program (known as a browser), e.g. NCSA Mosaic, Netscape
Navigator, runs on the user's computer and provides
two basic navigation operations: to follow a link or to send a query
to a server. A variety of client and server software is freely
available.
Most clients and servers also support "forms" which allow the user to
enter arbitrary text as well as selecting options from
customisable menus and on/off switches.
Following the widespread availability of web browsers and servers, many
companies from about 1995 realised they could use
the same software and protocols on their own private internal TCP/IP
networks giving rise to the term "intranet".
If you don't have a WWW browser, but you are on the Internet, you can access the Web using the command:
telnet www.w3.org
(Internet address 128.141.201.74) but it's much better if you install a browser on your own computer.
The World Wide Web Consortium is the main standards body for the web.
Command line interfaces usually provide greater flexibility than graphical
user interfaces, at the cost of being harder for the
novice to use. Consequently, some hackers look down on GUIs as designed
For The Rest Of Them.
(12 Jan 1996)
2. An exercise in experimental epistemology.
3. A form of art, ostensibly intended for the instruction of computers,
which is nevertheless almost inevitably a failure if other
programmers can't understand it.
Historically, MUDs (and their more recent progeny with names of MU-
form) derive from a hack by Richard Bartle and Roy
Trubshaw on the University of Essex's DEC-10 in 1979. It was a game
similar to the classic Colossal Cave adventure, except
that it allowed multiple people to play at the same time and interact
with each other. Descendants of that game still exist today
and are sometimes generically called BartleMUDs. There is a widespread
myth that the name MUD was trademarked to the
commercial MUD run by Bartle on British Telecom (the motto: "You haven't
*lived* 'til you've *died* on MUD!"); however,
this is false - Richard Bartle explicitly placed "MUD" in the PD in
1985. BT was upset at this, as they had already printed
trademark claims on some maps and posters, which were released and
created the myth.
Students on the European academic networks quickly improved on the MUD
concept, spawning several new MUDs
(VAXMUD, AberMUD, LPMUD). Many of these had associated bulletin-board
systems for social interaction. Because these
had an image as "research" they often survived administrative hostility
to BBSs in general. This, together with the fact that
Usenet feeds have been spotty and difficult to get in the UK, made
the MUDs major foci of hackish social interaction there.
AberMUD and other variants crossed the Atlantic around 1988 and quickly
gained popularity in the US; they became nuclei for large hacker communities
with only loose ties to traditional hackerdom (some observers see parallels
with the growth of Usenet
in the early 1980s). The second wave of MUDs (TinyMUD and variants)
tended to emphasise social interaction, puzzles, and
cooperative world-building as opposed to combat and competition. In
1991, over 50% of MUD sites are of a third major
variety, LPMUD, which synthesises the combat/puzzle aspects of AberMUD
and older systems with the extensibility of
TinyMud. The trend toward greater programmability and flexibility will
doubtless continue.
The state of the art in MUD design is still moving very rapidly, with
new simulation designs appearing (seemingly) every month.
There is now a move afoot to deprecate the term MUD itself, as newer
designs exhibit an exploding variety of names
corresponding to the different simulation styles being explored.
UMN MUD Gopher page.
U Pennsylvania MUD Web page.
See also bonk/oif, FOD, link-dead, mudhead, MOO, MUCK, MUG, MUSE, talk mode.
MORE
(16 Mar 1995)
Hundreds of emoticons have been proposed, but only a few are in common use. These include:
:-) "smiley face" (for humour, laughter,
friendliness, occasionally
sarcasm)
:-( "frowney face" (for sadness, anger, or upset)
;-) "half-smiley" (ha ha only serious); also
known as "semi-smiley" or
"winkey face".
:-/ "wry face"
These may become more comprehensible if you tilt your head sideways,
to the left. The first two are by far the most frequently
encountered. Hyphenless forms of them are common on CompuServe, GEnie,
and BIX; see also bixie. On Usenet, "smiley" is
often used as a generic term synonymous with emoticon, as well as specifically
for the happy-face emoticon.
It appears that the emoticon was invented by one Scott Fahlman on the
CMU bboard systems around 1980. He later wrote: "I
wish I had saved the original post, or at least recorded the date for
posterity, but I had no idea that I was starting something that
would soon pollute all the world's communication channels." [GLS confirms
that he remembers this original posting].
As with exclamation marks, overuse of the smiley is a mark of loserhood!
More than one per paragraph is a fairly sure sign that
you've gone over the line.
(02 Dec 1994)
Unix has the talk program and protocol and its variants xtalk and ytalk
for the X Window System; VMS has phone; Windows
for Workgroups has chat. ITS also has a talk system. These split the
screen into separate areas for each user.
Unix's write command can also be used, though it does not attempt to
separate input and output on the screen. Internet Relay
Chat is a similar concept for interactive conversation over the Internet.
Users of such systems are said to be in talk mode which has many conventional abbreviations.
(24 Sep 1996)
2. In jargon, refers to doing something while people are watching or
waiting. "I asked her how to find the calling procedure's
program counter on the stack and she came up with an algorithm in real
time."
Used to describe a system that must guarantee a response to an external event within a given time.
There are some interesting implementations of artificial life using
strangely shaped blocks. A video, probably by the company
Artificial Creatures who build insect-like robots in Cambridge, MA
(USA), has several mechanical implementations of artificial
life forms.
See also evolutionary computing, life.
[Christopher G. Langton (Ed.), "Artificial Life", Proceedings Volume
VI, Santa Fe Institute Studies in the Sciences of
Complexity. Addison-Wesley, 1989].
A number of evolutionary computational models have been proposed, including
evolutionary algorithms, genetic algorithms, the
evolution strategy, evolutionary programming, and artificial life.
The Hitchhiker's Guide to Evolutionary Computation.
Bibliography.
Usenet newsgroup: comp.ai.genetic.
(02 Mar 1995)
(EA) An algorithm which incorporates aspects of natural selection or
survival of the fittest. An evolutionary algorithm maintains a
population of structures (usually randomly generated initially), that
evolves according to rules of selection, recombination,
mutation and survival, referred to as genetic operators. A shared "environment"
determines the fitness or performance of each
individual in the population. The fittest individuals are more likely
to be selected for reproduction (retention or duplication), while
recombination and mutation modify those individuals, yielding potentially
superior ones.
EAs are one kind of evolutionary computation and differ from genetic
algorithms. A GA generates each individual from some
encoded form known as a "chromosome" and it is these which are combined
or mutated to breed new individuals.
EAs are useful for optimisation when other techniques such as gradient
descent or direct, analytical discovery are not possible.
Combinatoric and real-valued function optimisation in which the optimisation
surface or fitness landscape is "rugged", possessing
many locally optimal solutions, are well suited for evolutionary algorithms.
(03 Feb 1995)
GAs are useful for multidimensional optimisation problems in which the
chromosome can encode the values for the different
variables being optimised.
Illinois Genetic Algorithms Laboratory (IlliGAL).
(03 Feb 1995)
Por contenidose entenderá en la presente comunicación
los datos, textos, sonidos, imágenes o combinaciones multimedios
de ellos, representados
en formato analógico o digital sobre diversos tipos de soportes,
tales como papel, microfilm o dispositivos de almacenamiento magnético
u óptico.
Los diferentes segmentos de esta industria son:
La industria de los contenidos es, desde el punto de vista del valor de mercado y del empleo, el sector más importante de la industria de la información lato sensu, que incluye las industrias de equipos y servicios de telecomunicaciones, sistemas y servicios informáticos, electrónica de consumo y equipos de oficina.