1. 1 - Early Computing and 2 – Electronic Computing
CS 1 Introduction to Computers and Computer Technology
Rick Graziani
Fall 2017

2. Computer Science
Computer Science: The discipline that seeks to build a scientific foundation for such topics as:
computer design
computer programming
information processing
algorithmic solutions of problems
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3. What is a computer?
A computer is a electromechanical device which can be programmed to change (process) information from one form to another.
Do exactly as they are told.
Digital devices: Understand only two different states (OFF and ON)
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4. Role of Algorithms
Hardware
Software
Programming
Program
Algorithm
Algorithm: A set of steps that defines how a task is performed
Program: A representation of an algorithm
Programming: The process of developing a program
Software: Programs and algorithms
Hardware: Equipment used to input information (data) and output the results of the programs, algorithms.
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5. An algorithm for a magic trick
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6. History of Algorithms
The study of algorithms was originally a subject in mathematics.
Early examples of algorithms
Long division algorithm
Euclidean Algorithm
Let’s take a look at Euclidean Algorithm
Just to see that YOU can do this stuff!
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7. The Euclidean algorithm
Euclidean algorithm (also called Euclid's algorithm) is an algorithm to determine the greatest common divisor (GCD) of two elements.
One of the oldest algorithms known, dating back to the ancient Greeks.
Greatest common divisor (GCD): The largest positive integer that divides both numbers without remainder
I.e. The largest number that can go into two numbers evenly.
Examples:
15 and 6, the GCD is 3
15 / 3 = / 3 = 2
48 and 40, the GCD is 8
48 / 8 = / 8 = 5
Euclid, 300 BC, "The Father of Geometry“ was a Greek mathematician
Euclid 200 ton dump truck
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8. The Euclidean algorithm
Step 1:
M = 15, N = 6
Step 2:
M / N
15 / 6 = 2, R = 3
Step 3:
R <> 0
M = 6, N = 3
6 / 3 = 2, R = 0
Step 3
R = 0
Greatest common divisor: N = 3
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9. The Euclidean algorithm
Step 1:
M = 48, N = 40
Step 2:
M / N
___ / ___ = __, R = __
Step 3:
R <> 0
M = ___, N = __
___ / ___ = __, R = __
Step 3
R = __
Greatest common divisor: N = _ 48 40 1 8 40 8 40 8 5 8
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10. Origins of Computing Machines
Pascal’s mechanical calculator
Windows Abacus 
Early computing devices
Abacus: positions of beads represent numbers
Gear-based machines (1600s-1800s)
Positions of gears represent numbers
Blaise Pascal, Wilhelm Leibniz, Charles Babbage
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11. Babbage’s Difference Engine
Part of the Difference Engine (below)
Replica of Difference Engine (right)
Babbage is credited with inventing the first mechanical computer that eventually led to more complex designs.
The first difference engine was composed of around 25,000 parts, weighed fifteen tons (13,600 kg), and stood 8 ft (2.4 m) high. Although he received ample funding for the project, it was never completed. (Wikipedia)
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12. Early Data Storage Punched cards
First used in Jacquard Loom (1801) to store patterns for weaving cloth
Storage of programs in Babbage’s Analytical Engine
Popular through the 1970’s
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13. Jacquard loom
The Jacquard loom was the first machine to use punch cards to control a sequence of operations.
Did not do computation, but important in history of computer science.
The ability to change the pattern of the loom's weave by simply changing cards
An important conceptual precursor to the development of computer programming. (Wikipedia)
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14. Augusta Ada Byron Augusta Ada King, Countess of Lovelace (1815-1852)
Mainly known for having written a description of Charles Babbage's early mechanical general-purpose computer, the analytical engine.
She is also known as the "first programmer".
The computer language Ada, created by the U.S. Defense Department, was named after Ada Lovelace.
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15. Early Electromechanical Computers
Here is a brief overview of some of the early computers and trends in computing.
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16. First Generation – Mechanical Relays
1930’s – Vacuum tubes were used as electronic circuits or electronic switches.
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17. Mechanical Relays
The brains of early electronic computers were mechanical relays or mechanical switches.
The control wire determines whether the circuit is open or closed.
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18. Mechanical Relays
When current flows through the coil, an electromagnetic field is created, which attracts the metal arm inside the relay, snapping it shut and …..
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19. Mechanical Relays …. completing the circuit.
Similar to a water faucet that controls the flow of water.
Relay – electrons instead of water.
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20. Mechanical Relays
Disadvantage is the arm has “mass” which makes it slow.
About 50 times per second
Not fast enough for solving large computational problems
Wear-and-tear
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21. Mechanical Relays 3,500 mechanical relays
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22. “Moth found trapped between points at Relay # 70, Panel F, of the Mark II Aiken Relay Calculator while it was being tested at Harvard University, 9 September 1947.
The operators affixed the moth to the computer log, with the entry: “First actual case of bug being found”. They put out the word that they had “debugged” the machine.
In 1988, the log, with the moth still taped by the entry, was in the Naval Surface Warfare Center Computer Museum at Dahlgren, Virginia.
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23. First Generation – Mechanical Relays
Needed a faster, more reliable alternative to mechanical relays.
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24. Second Generation – Vacuum Tubes
1904 – John Ambrose Fleming invented the thermionic valve (vacuum tube).
Later, developed as an electronic switch… no moving parts!
Switched thousands of times per second
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25. Second Generation – Vacuum Tubes
1930’s – Vacuum tubes were used as electronic circuits or electronic switches.
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26. Second Generation – Vacuum Tubes
The bombe UK ( s) was an electro-mechanical device used by British cryptologists to help decipher German Enigma-machine-encrypted secret messages during World War II.
The initial design of the bombe was produced in the UK by Alan Turing.
Used thermionic valves (vacuum tubes) for the high speed circuits
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27. Rick Graziani graziani@cabrillo.edu

28. ENIAC
First large-scale electronic digital computer was ENIAC (Electronic Numerical Integrator and Calculator)
First truly general purpose computer
30 feet long, 8 feet wide, and 8 feet high
5,000 additions every second, (incredibly slow by today’s standards).
Vacuum tube failures common
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29. ENIAC
Grace Hopper, one of the first programmers on the Mark-I and the ENAIC.
She was the developer of the programming language COBOL, says, “The Mark-1 was the first machine that assisted the power of man’s brain instead of the strength of his arm.”
ENIAC was made up of vacuum tubes, over 18,000 of them!
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30. Third Generation – Transistors
Needing greater speed and reliability, a better electronic switch was needed.
Walter Brittain, John Bardeen, and Willaim Shockley invented the transistor at Bell Laboratories
Replaced the vacuum tube as an electronic switch
Can switch 10,000 times per second
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31. Third Generation - Transistors
Transistors were:
Solid state (solid material)
Smaller
Faster
More reliable
Less expensive
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32. IBM 608 and 360 1957 - IBM 608 – First fully transistorized computer
3,000 transistors
4,500 additions per second
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33. Transistors
Today’s computers use transistors that are 50 nanometers in size
Thickness of paper is about 100,000 nanometers thick
Super fast – switch states millions of times per second and last for decades
Developed in “Silicon Valley”
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34. Fourth Generation – Integrated Circuits
1959, Jack Kirby and Robert Noyce at Fairchild Semiconductor (who was later to become the cofounder of Intel Corp.) developed the first integrated circuit (silicon chip or microchip).
An integrated circuit (IC) is a system of interrelated circuits packaged together on a single sliver of silicon.
It is a way of placing multiple (millions) transistor devices into as single, smaller device, the “microchip.”
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35. 1960 – IBM 360
1 addition every billionth of a second (nanosecond), or a billion additions every second
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36. Fourth Generation – Integrated Circuits
ICs, chips, were:
Smaller
Faster
More reliable
Less expensive
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37. Fifth Generation - Microprocessor
A microprocessor is a Central Processing Unit (CPU) on a single chip.
1971, Intel Corp. introduced the first microprocessor chip.
Intel 4004
108 kHz and contained (equivalent of) 2300 transistors
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38. IBM used it for calculators not computers
Busicom desk-top printing calculator, the world’s first commercial product to use a microprocessor.
Used the Intel 4004 CPU.
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39. Altair 8800
Ed Roberts and the first microcomputer or personal computer (for the consumer) the Altair 8800
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40. MITS Altair 8800
Microcomputer - a computer which has a microprocessor.
Used the Intel 8080 Microprocessor
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41. Microprocessors
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42. Personal Computers
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43. Computer Basics
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44. Embedded Computers
Embedded computers – Computers found inside consumer goods in order to enhance their function.
Cars today might have as many as 50 microprocessors on them.
Some of the reasons for this increase in the number of microprocessors are:
Meet emissions and fuel-economy standards
Advanced diagnostics
Reduction of the amount of wiring in cars
New safety features
New comfort and convenience features
Sensors, wearables, medical devices, and more
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45. Special Purpose Computers
Special purpose or dedicated computers – A device with a specific purpose such as game system or information kiosk.
ATM Skimming:
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46. Computer is Hardware and Software
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47. Hardware versus Software
Hardware = The physical components that make up a computer system.
More in a moment…
Much more on all of these items in later presentations!
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48. Hardware versus Software
Software = The programs (instructions) that tell the computer what to do.
System Software
Application Software
Stored on a storage media such as hard disk, CD-ROM, floppy disk, tape, etc.
More later…
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49. The Processor: The CPU
CPU (Central Processing Unit) = A complex collection of electronic circuits on one or more integrated circuits (chips) which:
1. executes the instructions in a software program
2. communicates with other parts of the computer system, especially RAM and input devices
The CPU is the computer!
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50. RAM (Random Access Memory)
RAM (Random Access Memory) = integrated circuits (chips) used to temporarily store software (programs, instructions) and data
“primary” storage for the CPU
electronic switches, storing ON’s and OFF’s
Temporarily stores for the CPU:
Software
operating system software
application software
Data
data (documents, spreadsheets, etc.)
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51. RAM Inserting RAM RAM is TEMPORARY memory RAM is volatile
stores ON and OFF bits (software and data) electrically
when power goes off, everything in RAM is lost
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52. RAM: Speed Why does the CPU use RAM? The CPU is very FAST!
The CPU needs the instructions (software) and data as quickly as possible
If the CPU has to wait, so does the user
Why doesn’t the CPU use permanent storage like disk drives?
Too slow
EXAMPLE: Spellchecker
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53. ROM (Read Only Memory)
ROM (Read Only Memory) = integrated circuits (microchips) that are used to permanently store start-up (boot) instructions and other critical information
Read Only = information which:
Cannot be changed
Cannot be removed
Cannot be appended (added to)
Fixed by manufacturer
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54. ROM (Read Only Memory)
ROM is sometimes known as ROM BIOS (Basic Input Output System software)
ROM permanently contains:
start-up (boot) instructions
instructions to do “low level” processing of input and output devices, such as the communications with the keyboard and the monitor
Firmware = software program which is stored permanently on a microchip, such as the software on the ROM chip
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55. Application Software Performs specific tasks: Word processing
Calculations
Information storage and retrieval
Accounting
Cannot function without the OS (Operating System)
Written for a specific operating system and computer hardware.
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56. Operating System Software
Loads automatically when you switch on a computer
Main roles:
Controls hardware and software
Permits you to manage files
Acts as intermediary between user and applications
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57. Operating System Software
Software which manages the overall operation of the computer system including:
hardware (CPU, RAM, I/O)
security
system interface
application interface
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58. 1 - Early Computing and 2 – Electronic Computing
CS 1 Introduction to Computers and Computer Technology
Rick Graziani
Fall 2017