My speciality. Шепелева М.А - 15 стр.

      3. Section III

      3.1 Text 1 System Buses

       At a top level, a computer consists of CPU, memory and I/O components,
with one or more modules of each type. These components are interconnected in
some fashion to achieve the basic function of the computer, which is to execute
programs. We can describe a computer system by describing the external behavior
of each component, that is the data and controls signals that is exchanges with
other components, and describing the interconnection structure and the controls
required to manage the use of the interconnection structure.
        This top-level view of structure and function is important because of its
explanatory power in understanding the nature of a computer. Equally important is
its use to understand the increasingly complex issues of performance evaluation,
alternate path ways, the magnitude of system failures is a component fails and the
ease of adding performance enhancements. In many cases, requirements for greater
system power and fail-safe capabilities are being met by changing the design rather
that merely increasing the speed and reliability of individual components.
        The basic function performed by a computer is program execution. The
program to be executed consists of a set of instructions stored in memory. The
central processing unit (CPU) does the actual work by executing instructions
specified in the program. In order to gain a greater understanding of this function
and of the way in which the major components of the computer interact to execute
a program, we need to look in more detail at the process of program execution. The
simplest point of view is to consider instruction processing as consisting of two
steps: The CPU reads (fetches) instructions from memory one at a time, and it
executes each instruction. Program execution consists of repeating the process of
instruction fetch and instruction execution. Of course, the execution of an
instruction may itself iiwolve a number of steps. We can justify the breakdown of
instruction processing into the two stages of fetch and execution as follows. The
instruction fetch is a common operation for each instruction, and consists of
reading an instruction from a location in memory. The instruction execution may
involve several operations and depends on the nature of the instruction.
        The processing required for a single instruction is called an instruction
cycle. The two steps are referred to as the fetch cycle and the execute cycle.
Program execution halts only if the machine is turned off, some sort of
unrecoverable error occurs, or a program instruction that halts the computer is
encountered.

      3.1.1 Translate the words:

external behavior, exchange, structure, function, explanatory, magnitude,
reliability, execution, breakdown, single, unrecoverable.