<< preface

this blog is nina wenhart's collection of resources on the various histories of new media art. it consists mainly of non or very little edited material i found flaneuring on the net, sometimes with my own annotations and comments, sometimes it's also textparts i retyped from books that are out of print.

it is also meant to be an additional resource of information and recommended reading for my students of the prehystories of new media class that i teach at the school of the art institute of chicago in fall 2008.

the focus is on the time period from the beginning of the 20th century up to today.

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2008-06-25

>> Claude Shannon, Information System, Bit



In his 1948 paper "A Mathematical Theory of Communication", Claude Shannon first defines the term "bit" as a unit for information and the constituents of a general information system.
(The Bell System Technical Journal, Vol. 27, pp. 379–423, 623–656, July, October, 1948)

link to the full pdf: http://cm.bell-labs.com/cm/ms/what/shannonday/shannon1948.pdf




>> bit
"The choice of a logarithmic base corresponds to the choice of a unit for measuring information. If the base 2 is used the resulting units may be called binary digits, or more briefly bits, a word suggested by J. W. Tukey. A device with two stable positions, such as a relay or a flip-flop circuit, can store one bit of information. N such devices can store N bits, since the total number of possible states is 2N and log2 2N =N. If the base 10 is used the units may be called decimal digits."


>> communication system
"By a communication system we will mean a system of the type indicated schematically in Fig. 1. It consists of essentially five parts:

1. An information source which produces a message or sequence of messages to be communicated to the receiving terminal. The message may be of various types: (a) A sequence of letters as in a telegraph of teletype system; (b) A single function of time f (t) as in radio or telephony; (c) A function of time and other variables as in black and white television — here the message may be thought of as a function f (x;y; t) of two space coordinates and time, the light intensity at point (x;y) and time t on a pickup tube plate; (d) Two or more functions of time, say f (t), g(t), h(t)—this is the case in “threedimensional” sound transmission or if the system is intended to service several individual channels in multiplex; (e) Several functions of several variables—in color television themessage consists of three functions f (x;y; t), g(x;y; t), h(x;y; t) defined in a three-dimensional continuum—we may also think of these three functions as components of a vector field defined in the region — similarly, several black and white television sources would produce “messages” consisting of a number of functions of three variables; (f) Various combinations also occur, for example in television with an associated audio channel.

2. A transmitter which operates on the message in some way to produce a signal suitable for transmission over the channel. In telephony this operation consists merely of changing sound pressure into a proportional electrical current. In telegraphy we have an encoding operation which produces a sequence of dots, dashes and spaces on the channel corresponding to the message. In a multiplex PCM system the different speech functions must be sampled, compressed, quantized and encoded, and finally interleaved properly to construct the signal. Vocoder systems, television and frequency modulation are other examples of complex operations applied to the message to obtain the signal.

3. The channel is merely the medium used to transmit the signal from transmitter to receiver. It may be a pair of wires, a coaxial cable, a band of radio frequencies, a beam of light, etc.

4. The receiver ordinarily performs the inverse operation of that done by the transmitter, reconstructing the message from the signal.

5. The destination is the person (or thing) for whom the message is intended."

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... is a Media Art historian and independent researcher. She is currently writing on "speculative archiving && experimental preservation of Media Art" and graduated from Prof. Oliver Grau's Media Art Histories program at the Danube University in Krems, Austria with a Master Thesis on Descriptive Metadata for Media Arts. For many years, she has been working in the field of archiving/documenting Media Art, recently at the Ludwig Boltzmann Institute for Media.Art.Research and before as the head of the Ars Electronica Futurelab's videostudio, where she created their archives and primarily worked with the archival material. She was teaching the Prehystories of New Media Class at the School of the Art Institute of Chicago (SAIC) and in the Media Art Histories program at the Danube University Krems.