Information Technology Reference
In-Depth Information
&
CHAPTER 1
Introduction to Computer Systems
The technological advances witnessed in the computer industry are the result of a
long chain of immense and successful efforts made by two major forces. These
are the academia, represented by university research centers, and the industry,
represented by computer companies. It is, however, fair to say that the current tech-
nological advances in the computer industry owe their inception to university
research centers. In order to appreciate the current technological advances in the
computer industry, one has to trace back through the history of computers and
their development. The objective of such historical review is to understand the
factors affecting computing as we know it today and hopefully to forecast the
future of computation. A great majority of the computers of our daily use are
known as general purpose machines. These are machines that are built with no
specific application in mind, but rather are capable of performing computation
needed by a diversity of applications. These machines are to be distinguished
from those built to serve (tailored to) specific applications. The latter are known
as special purpose machines. A brief historical background is given in Section 1.1.
Computer systems have conventionally been defined through their interfaces at
a number of layered abstraction levels, each providing functional support to its pre-
decessor. Included among the levels are the application programs, the high-level
languages, and the set of machine instructions. Based on the interface between
different levels of the system, a number of computer architectures can be defined.
The interface between the application programs and a high-level language is
referred to as a language architecture. The instruction set architecture defines the
interface between the basic machine instruction set and the runtime and I
/
O control.
A different definition of computer architecture is built on four basic viewpoints.
These are the structure, the organization, the implementation, and the performance.
In this definition, the structure defines the interconnection of various hardware com-
ponents, the organization defines the dynamic interplay and management of the
various components, the implementation defines the detailed design of hardware
components, and the performance specifies the behavior of the computer system.
Architectural development and styles are covered in Section 1.2.
