Mohd. E. Seno

The rules of logic specify the meaning of mathematical statements. For instance, these rules
help us understand and reason with statements such as “There exists an integer that is
not the sum of two squares” and “For every positive integer n, the sum of the positive integers
not exceeding n is n(n + 1)/2.” Logic is the basis of all mathematical reasoning, and of all
automated reasoning. It has practical applications to the design of computing machines, to the
specification of systems, to artificial intelligence, to computer programming, to programming

A modern general-purpose C/S consists of a CPU and a number of device controllers that are connected through a common bus that provide access to shared memory. See figure (2.1).
Figure (2.1) A modern computer system

Operating systems is a program that acts as an intermediary between a
user of a computer and the computer hardware (H/W). The purpose of an
operating system is to provide the environment in which the user can execute
programs. The O.S. is a resource allocator (managers all resources, decides
between conflicting requests for efficient and fair resource use) and is a
control program (controls execution of programs ) to prevent errors and
improper use of the computer.
1.2 Computer System Components: