"Hugo Cornwall "The Hacker's handbook"" - читать интересную книгу автора

CHAPTER 4
Targets

Wherever hackers gather, talk soon moves from past achievements
and adventures to speculation about what new territory might be
explored. It says much about the compartmentalisation of computer
specialities in general and the isolation of micro- owners from
mainstream activities in particular that a great deal of this
discussion is like that of navigators in the days before Columbus:
the charts are unreliable, full of blank spaces and confounded with
myth.
In this chapter I am attempting to provide a series of notes on
the main types of services potentially available on dial-up, and to
give some idea of the sorts of protocols and conventions employed.
The idea is to give voyagers an outline atlas of what is interesting
and possible, and what is not.

On-line hosts

On-line services were the first form of electronic publishing: a
series of big storage computers--and on occasion, associated
dedicated networks -- act as hosts to a group of individual databases
by providing not only mass data storage and the appropriate 'search
language' to access it, but also the means for registering, logging
and billing users. Typically, users access the on-line hosts via a
phone number which links into a a public data network using packet
switching (there's more on these networks in chapter 7).
The on-line business began almost by accident; large corporations
and institutions involved in complicated technological developments
found that their libraries simply couldn't keep track of the
publication of relevant new scientific papers, and decided to
maintain indices of the papers by name, author, subject-matter, and
so on, on computer. One of the first of these was the armaments and
aircraft company, Lockheed Corporation.
In time the scope of these indices expanded and developed and
outsiders -- sub-contractors, research agencies, universities,
government employees, etc were granted access. Other organisations
with similar information-handling requirements asked if space could
be found on the computer for their needs.
Eventually Lockheed and others recognised the beginnings of a quite
separate business; in Lockheed's case it lead to the foundation of
Dialogue, which today acts as host and marketing agent for almost 300
separate databases. Other on-line hosts include BRS (Bibliographic
Retrieval Services), Comshare (used for sophisticated financial
modelling), DataStar, Blaise (British Library) I P Sharp, and
Euronet-Diane.
On-line services, particularly the older ones, are not especially
user-friendly by modern standards. They were set up at a time when
both core and storage memory was expensive, and the search languages