Information Technology Reference
In-Depth Information
gather. Computers and other electronic devices within range of the hotspot commu-
nicate with the hotspot using radio waves. Most hotspots use a technology known as
Wi-Fi.
The previous two sections surveyed technological developments related to manipulating
and transmitting information, respectively. This section focuses on the development of
technologies to store and retrieve information.
As civilizations expanded around 6,000 years ago, writing systems were developed to
allow the recording and communication of various types of information, such as laws
and financial records. There are three general types of writing systems. In a logography
each character represents a word, in a syllabary each character represents a syllable, and
in an alphabet each character represents a phoneme.
Around 750 BC the Greeks developed the first true alphabet: an alphabet represent-
ing vowel sounds as well as consonant sounds. Compared with earlier writing systems
developed in Mesopotamia and Egypt, the 24-letter Greek alphabet was a simple, effi-
cient way of transforming the spoken word into written form, and it marked an impor-
tant milestone on the journey of civilization from an oral culture to a written culture.
The English alphabet we use today is a direct descendant of the alphabet used by the
ancient Greeks.
Two thousand years ago, important information was recorded on papyrus scrolls
wrapped around wooden rods. Papyrus had to be stored this way to keep from breaking
apart. Even so, the ends of papyrus scrolls tended to fall off.
The development of the codex was a significant advance in information storage and
retrieval technology. A codex was made up of rectangular pages sewn together on one
side. These pages were made out of sheepskin (parchment) or calfskin (vellum). The
codex was superior to papyrus in two ways. First, the codex was much more durable
than a papyrus roll. Second, since it was divided into pages, the codex made it much
easier for readers to find a particular passage: they could simply flip to the desired page.
Between the second and fourth centuries, the codex gradually replaced the scroll as
the most popular method of recording important information. The Church accelerated
the transition by insisting that all sacred texts be recorded in codices, to distinguish them
from Hebrew scriptures kept on scrolls.
After the fall of the Roman Empire, Irish monks preserved Western culture by
copying Greco-Roman and Judeo-Christian texts into codices [39]. Centuries later, most
codices were produced using a process of wood engraving. A craftsman would take a
block of wood and laboriously chisel away the background for a portion of a page,
leaving the letters and illustrations raised. When all the wooden blocks for a page were
