Discuss the internal structure of a digital computer with the importance of each
block.
Answers
Answer:
The digital computer is a digital system that performs various computational tasks. The word
digital implies that the information in the computer is represented by variables that take a
limited number of discrete values. These values are processed internally by components that
can maintain a limited number of discrete states. The decimal digits 0, 1, 2…9, for example,
provide 10 discrete values. The first electronic digital computers, developed in the late 1940s,
were used primarily for numerical computations. In this case the discrete elements are the
digits. From this application the term digital computer has emerged. In practice, digital
computers function more reliably if only two states are used. Because of the physical restriction
of components, and because human Logic tends to be binary (i.e., true-or-false, yes or- no
statements digital components that are constrained to take discrete values are further
constrained to take only two values and are said to be binary.
Digital computers use the binary number system, which has two digits: 0 and 1. A binary digit
is called a bit. Information is represented in digital computers in groups of bits. By using
various coding techniques, groups of bits can be made to represent not only binary numbers but
also other discrete symbols, such as decimal digits or letters of the alphabet. By judicious use of
binary arrangements and by using various coding techniques, the groups of bits are used to
develop complete sets of instructions for performing various types of computations.
Computer technology has made incredible improvement in the past half century. In the early
part of computer evolution, there were no stored-program computer, the computational power
was less and on the top of it the size of the computer was a very huge one. Today, a personal
computer has more computational power, more main memory, more disk storage, smaller in
size and it is available in affordable cost. This rapid rate of improvement has come both from
advances in the technology used to build computers and from innovation in computer design.
In this course we will mainly deal with the innovation in computer design. The task that the
computer designer handles is a complex one: Determine what attributes are important for a new
machine, then design a machine to maximize performance while staying within cost constraints.
This task has many aspects, including instruction set design, functional organization, logic
design, and implementation. While looking for the task for computer design, both the terms
computer organization and computer architecture come into picture.
It is difficult to give precise definition for the terms Computer Organization and Computer
Architecture. But while describing computer system, we come across these terms, and in
literature, computer scientists try to make a distinction between these two terms. Computer
architecture refers to those parameters of a computer system that are visible to a programmer or
those parameters that have a direct impact on the logical execution of a program. Examples of
architectural attributes include the instruction set, the number of bits used to represent different
data types, I/O mechanisms, and techniques for addressing memory. Computer organization
refers to the operational units and their interconnections that realize the architectural
specifications. Examples of organizational attributes include those hardware details transparent
to the programmer, such as control signals, interfaces between the computer and peripherals,
and the memory technology used.