CSE 101 Computer Engineering Concepts

1
CSE 101Computer Engineering Concepts Algorithms

• Lecture 1
• Historical Thoughts

2
Introduction

• What is a computer?
• Computer as a useful tool
• Wide application area Companies, Schools,
  Airports, Hospitals, Banks, Military, Airports...
• Quite new A product of information age.
• Industrial ageElectricity, telephones, radio,
  automobiles, planes
• Information age Computers, Internet, Mobile
  Communication.

3
Calculation and Computation

• Calculation
• determining something by mathematical or logical
  methods
• Transforming one or more inputs into one or more
  results.
• Multiply 7 and 8.
• Computation
• can be defined as finding a solution to a problem
  from given inputs by means of an algorithm.
• Denotes a more general process involving data and
  algorithms.
• Algorithm A well-defined set of instructions to
  perform a certain task.
• A program that keeps records of students in a
  school and answers queries about the data it
  keeps.

4
Timeline of Computer Technology
1900 1800 BC The first use of place-value
number system (eg the decimal system value
of the number depends both on the digit
itself and the position of the digit)
1000 500 BC The invention of abacus the first
actual calculating mechanism known to man
300 600 AD The first use of the number 0, and
negative numbers (first appeared in India)
5
Pascal's and Leibniz's devices were the forebears
of today's desk-top computers, and derivations of
these machines continued to be produced until
their electronic equivalents finally became
readily available and affordable in the early
1970s.
6
In the early 1800s, a French silk weaver called
Joseph-Marie Jacquard invented a way of
automatically controlling the silk loom by
recording patterns of holes in a string of cards.
In the years to come, variations on Jacquard's
punched cards would find a variety of uses,
including representing the music to be played by
automated pianos and the storing of programs for
computers
IBM 80-column punched card format
7
Charles Babbage
The first device that might be considered to be a
computer in the modern sense of the word was
conceived in 1822 by the eccentric British
mathematician and inventor Charles Babbage.
The Difference Engine, which was reconstructed in
1970s from cast iron, bronze and steel, consisted
of 4,000 components, weighed three tons, and was
10 feet wide and 6½ feet tall.
In Babbage's time, mathematical tables, such as
logarithmic and trigonometric functions, were
generated by teams of mathematicians working day
and night on primitive calculators.
Due to the fact that these people performed
computations they were referred to as
"computers."
In fact the term "computer" was used as a job
description (rather than referring to the
machines themselves) well into the 1940s. This
term later became associated with machines that
could perform the computations on their own.
8
The Difference Engine was actually only partially
completed when Babbage conceived the idea of
another, more sophisticated machine called an
Analytical Engine (around 1830).
The Analytical Engine was intended to use loops
of Jacquards punched cards to control an
automatic calculator, which could make decisions
based on the results of previous computations.
This machine was also intended to employ several
features subsequently used in modern computers,
including sequential control, branching, and
looping.
9
George Boole
Boole made significant contributions in several
areas of mathematics, but was immortalized for
two works in 1847 and 1854, in which he
represented logical expressions in a mathematical
form now known as Boolean Algebra. Boole's work
was all the more impressive because, with the
exception of elementary school and a short time
in a commercial school, he was almost completely
self-educated.
10
Alan Turing
In 1937 Turing invented a theoretical computer as
an abstract "paper exercise." This theoretical
model, which became known as a Turing Machine,
was both simple and elegant, and subsequently
inspired many "thought experiments."
During World War II, Alan Turing worked as a
cryptographer, decoding codes and ciphers at one
of the British government's top-secret
establishments. Turing was a key player in the
breaking of the German's now-famous ENIGMA Code.
11
1943 1947 ENIAC Electronic Numerical
Integrator and Calculator
12
1943 1947 ENIAC Electronic Numerical
Integrator and Calculator

• It could do nuclear physics calculations (in
  two hours) which it would have taken 100
  engineers a year to do by hand.
• The system's program could be changed by rewiring
  a panel.

13
Johann von Neumann
In June 1944, the Hungarian- American
mathematician Johann (John) Von Neumann first
became aware of ENIAC. Von Neumann, who was a
consultant on the Manhattan Project, immediately
recognized the role that could be played by a
computer like ENIAC in solving the vast arrays of
complex equations involved in designing atomic
weapons.
14
In 1945, he published a paper titled First draft
of a report to the EDVAC
A memory containing both data and instructions.
Also to allow both data and instruction memory
locations to be read from, and written to, in any
desired order.
A calculating unit capable of performing both
arithmetic and logical operations on the data.
A control unit, which could interpret an
instruction retrieved from the memory and select
alternative courses of action based on the
results of previous operations.
The computer structure resulting from the
criteria presented in the "First Draft" is
popularly known as a von Neumann Machine, and
virtually all digital computers from that time
forward have been based on this architecture
15
SMIL, one of the first Swedish computers, built
at Lund University in the mid-fifties. The
original SMIL consisted of about 2000 vacuum
tubes. SMIL was the main university computer
for more than 15 years and wasn't decommissioned
until 1972. This picture shows SMIL as it looked
in 1956.
16
Two of the greatest inventions of the 20th
century Transistors and Integrated Circuits
Formed from materials known as semi-conductors,
not very well understood until 1950s
They would be much smaller, lighter and would
require less power than the vacuum tubes that
were being used until that time.
The world's first transistor, invented at Bell
Labs in 1947
Dr. John Bardeen, Dr. William Shockley, and Dr.
Walter Brattain, inventors
17
Transistors, may range in number from 2 to more
than 100,000, are integrated together on pieces
of silicon to produce Integrated Circuits to
perform more complex functions.
An integrated circuit contains transistors,
capacitors, resistors and other parts packed in
high density on one chip. The transistors,
resistors, and capacitors are formed very small,
and in high density on a foundation of silicon.
18
Microprocessors
The first microprocessor developed by Hoff
contained approximately 2,300 transistors and
could execute 60,000 operations per second.
In 1973 Intel presented the first true
general-purpose microprocessor, which contained
around 4,500 transistors and could perform
200,000 operations per second, and destined to be
the central processor of many of the early home
computers.
19
1973 The Intel Corporation delivers the first
integrated circuit capable of executing a
fully usable programme, the Intel 8080. The
microprocessor is born.
1977 The Apple Computer Company is started by
two college- dropouts in their garage, Steve
Jobs and Steve Wozniak. The machine uses
inexpensive parts and home color
television. The BASIC programming language
is written by Bill Gates of Microsoft.
1981 Microsoft provides the Disk Operating
System (DOS) for the IBM Personal Computer
Late 1980s The use of Windows operating shell
produced by Microsoft provides a Graphical User
Interface (GUI) for users
20
Computers can be generally classified by size
and power, though there is considerable overlap
personal computer A small, single-user
computer based on a microprocessor. In addition
to the microprocessor, a personal computer has a
keyboard for entering data, a monitor for
displaying information, and a storage device for
saving data. workstation A powerful,
single-user computer. A workstation is like a
personal computer, but it has a more powerful
microprocessor and a higher-quality monitor.
minicomputer A multi-user computer capable of
supporting from 10 to hundreds of users
simultaneously. mainframe A powerful
multi-user computer capable of supporting many
hundreds or thousands of users simultaneously.
supercomputer An extremely fast computer that
can perform hundreds of millions of instructions
per second.
21
The actual machinery -- wires, transistors, and
circuits is called the hardware the
instructions and data are called software.
All general-purpose computers require the
following hardware components memory Enables
a computer to store, at least temporarily, data
and programs. mass storage device Allows a
computer to permanently retain large amounts of
data. Common mass storage devices include disk
drives. input device Usually a keyboard and
mouse, the input device is the conduit through
which data and instructions enter a computer.
output device A display screen, printer, or
other device that lets you see what the computer
has accomplished. central processing unit
(CPU) The heart of the computer, this is the
component that actually executes instructions.
(If the CPU is built around a microprocessor
device, it is also referred to as a
Microprocessor Unit, MPU)