CC113B Flashcards
The word computer comes from the word “compute”, which
means, “to calculate”
Computer
The activity of processing data using a computer is called
Data Processing
CHARACTERISTICS OF
COMPUTERS
Automatic
Speed
Accuracy
Diligence
Versatility
No IQ
No feelings
invented the first mechanical adding
machine in 1642
Blaise Pascal
invented the first
calculator for multiplication in 1671
Baron Gottfried Wilhelm von Leibniz
originated in the United States
around 1880
Keyboard Machines
came up with the concept
of punched cards that were extensively used as input
media until late 1970s
Herman Hollerith
is considered to be the father of
modern digital computers
He designed “Difference Engine” in 1822
He designed a fully automatic analytical engine in
1842 for performing basic arithmetic functions
Charles Babbage
Integrated set of programs that controls the resources
(the CPU, memory, I/O devices, etc.) of a computer
system
System
MAIN
FUNCTIONS OF
AN OS
Process management
Memory management
File management
Security
Command interpretation
A process (also called job) is a program in execution
PROCESS
MANAGEMENT
Information stored in a file can be
accessed sequentially (in the order in which they are
stored, starting at the beginning)
Sequential access:
Information stored in a file can be
accessed randomly irrespective of the order in which
the bytes or records are stored
Random access
Deals with protecting the various resources and information
of a computer system against destruction and unauthorized
access
Security
Provides a set of commands using which the user can give
instructions to the computer for getting some job done by it
COMMAND
INTERPRETATION
Command-line interface:
Graphical User Interface (GUI):
Developed in the early 1970s at Bell Laboratories by Ken
Thompson and Dennis Ritchie
UNIX OS
APPLICATION
SOFTWARE
WORD
PROCESSING
PACKAGE
SPREADSHEET
PACKAGE
GRAPHICS
PACKAGE
PERSONAL
ASSISTANCE
PACKAGE
Constant is a value that never changes.
Three primitive types of constants supported in C are:
▸ Integer
▸ Real
▸ Character
CONSTANTS
Entity whose value may vary during program execution
VARIABLES
DEVELOPED THE C++
Bjarne Stroustrup
