NCR PC4I, Руководство пользователя

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HISTORICAL DATA
throughout an entire building, and another can be so small that the
entire system fits within a wristwatch.
COMPUTER CAPABILITIES
A computer can perform only a few basic arithmetic and data
handling operations. It can add, subtract, compare one quantity to
another, and move or modify data. In most computers, even
multiplication and division are performed through repetitive addi­
tion and subtraction. It executes operations in sequence, but can be
told to “jump” or “branch” out of sequence to another instruction in
the program, either unconditionally (every time) or conditionally. For
example, you could branch if two variables were equal, or not branch
if the same two variables were unequal. Each time your computer
performs a task, i.e., reading or writing words and sentences, it must
perform one or more of the basic operations.
COMPUTER ADVANTAGES
The computer's power lies in the fact that it is: fast, accurate, and has
storage and recall. Fast — it can perform thousands of arithmetic
operations and comparisons in the time it took you to read this
sentence. Accurate — your computer gives exactly the same answer to
the same calculation or comparison, as long as the same program is
used, regardless of how often it occurs. Storage and recall — it stores
programs, files, and tables of information that can be read back into
the computer to update, compare, or for whatever purpose you
require.
COMPUTER LIMITATIONS
A computer has tremendous capabilities and probably appears to
have a very fast, efficient mind, but it does not have the qualities of a
human mind such as intuition, deductive reasoning (not yet, anyway),
or subjective judgment. The computer’s decisions can be objective
only — Is that color RED or BLUE? YES or NO? — Never subjective
— Which color is prettier?
The computer must be told what to do at all times by using programs.
Within its capabilities, the limitations of what your computer can do
for you are imposed by physical makeup — hardware, i.e., amount of
storage, speed of processing, existence of optional features such as a
printer — by the degree of cleverness, thoroughness and precision
with which the programs are designed and written, and by your
imagination.
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