Typewriter, experimental

The resolution of typewriter graphics is limited (see Figure 1). Nevertheless, resolution was sufficient for qualitative comparisons, and the results were immediately available. The Gex function was included in a function that allowed modification of parameters simply and produced graphs of one or a number of the spectra that can be constructed out of the elements of u and du/cL). For comparison with experimental spectra, the frequency variable W was converted to the equivalent field that would obtain at a microwave frequency of 9.5 GHz. 

The inverted search process, in conjunction with modern developments in computing, lends itself to on-line information retrieval. The librarian-information officer, or even the scientist himself, sits at a typewriter terminal connected, over telephone lines, to the computer. He explores the dictionary, establishes the search formulation, and then the computer searches for the references and prints them out before his eyes. In the USA this service is known as MEDLINE and is the main means of access to the MEDLARS data base. Various experimental services of this kind are in operation at European MEDLARS centres, but the relatively higher cost of telephone communication here makes it more expensive than batch searching. 

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