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

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 Rick Graziani graziani@cabrillo.edu

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) Rick Graziani graziani@cabrillo.edu Rick Graziani graziani@cabrillo.edu 3 3

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. Rick Graziani graziani@cabrillo.edu

An algorithm for a magic trick Rick Graziani graziani@cabrillo.edu

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! Rick Graziani graziani@cabrillo.edu

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 = 5 6 / 3 = 2 48 and 40, the GCD is 8 48 / 8 = 6 40 / 8 = 5 Euclid, 300 BC, "The Father of Geometry“ was a Greek mathematician Euclid 200 ton dump truck Rick Graziani graziani@cabrillo.edu

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 Rick Graziani graziani@cabrillo.edu

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 Rick Graziani graziani@cabrillo.edu

Origins of Computing Machines Pascal’s mechanical calculator - 1645 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 Rick Graziani graziani@cabrillo.edu

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) Rick Graziani graziani@cabrillo.edu

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 Rick Graziani graziani@cabrillo.edu

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) Rick Graziani graziani@cabrillo.edu

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. Rick Graziani graziani@cabrillo.edu

Early Electromechanical Computers Here is a brief overview of some of the early computers and trends in computing. Rick Graziani graziani@cabrillo.edu

First Generation – Mechanical Relays 1930’s – Vacuum tubes were used as electronic circuits or electronic switches. Rick Graziani graziani@cabrillo.edu

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. Rick Graziani graziani@cabrillo.edu

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 ….. Rick Graziani graziani@cabrillo.edu

Mechanical Relays …. completing the circuit. Similar to a water faucet that controls the flow of water. Relay – electrons instead of water. Rick Graziani graziani@cabrillo.edu

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 Rick Graziani graziani@cabrillo.edu

Mechanical Relays 3,500 mechanical relays Rick Graziani graziani@cabrillo.edu

“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. Rick Graziani graziani@cabrillo.edu

First Generation – Mechanical Relays Needed a faster, more reliable alternative to mechanical relays. Rick Graziani graziani@cabrillo.edu

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 Rick Graziani graziani@cabrillo.edu

Second Generation – Vacuum Tubes 1930’s – Vacuum tubes were used as electronic circuits or electronic switches. Rick Graziani graziani@cabrillo.edu

Second Generation – Vacuum Tubes The bombe UK (1939-1940s) 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 Rick Graziani graziani@cabrillo.edu

Rick Graziani graziani@cabrillo.edu

1946 - 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 Rick Graziani graziani@cabrillo.edu

1946 - 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! Rick Graziani graziani@cabrillo.edu

Third Generation – Transistors Needing greater speed and reliability, a better electronic switch was needed. 1947 - 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 Rick Graziani graziani@cabrillo.edu

Third Generation - Transistors Transistors were: Solid state (solid material) Smaller Faster More reliable Less expensive Rick Graziani graziani@cabrillo.edu

IBM 608 and 360 1957 - IBM 608 – First fully transistorized computer 3,000 transistors 4,500 additions per second Rick Graziani graziani@cabrillo.edu

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” Rick Graziani graziani@cabrillo.edu

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.” Rick Graziani graziani@cabrillo.edu

1960 – IBM 360 1 addition every billionth of a second (nanosecond), or a billion additions every second http://www.youtube.com/watch?v=1OdRHImbPug Rick Graziani graziani@cabrillo.edu

Fourth Generation – Integrated Circuits ICs, chips, were: Smaller Faster More reliable Less expensive Rick Graziani graziani@cabrillo.edu

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 Rick Graziani graziani@cabrillo.edu

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. Rick Graziani graziani@cabrillo.edu

1975 - Altair 8800 Ed Roberts and the first microcomputer or personal computer (for the consumer) the Altair 8800 http://www.youtube.com/watch?v=vAhp_LzvSWk Rick Graziani graziani@cabrillo.edu

MITS Altair 8800 Microcomputer - a computer which has a microprocessor. Used the Intel 8080 Microprocessor Rick Graziani graziani@cabrillo.edu

Microprocessors Rick Graziani graziani@cabrillo.edu

Personal Computers Rick Graziani graziani@cabrillo.edu

Computer Basics Rick Graziani graziani@cabrillo.edu 43

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 Rick Graziani graziani@cabrillo.edu Rick Graziani graziani@cabrillo.edu 44 44

Special Purpose Computers Special purpose or dedicated computers – A device with a specific purpose such as game system or information kiosk. ATM Skimming: http://www.youtube.com/watch?v=m3qK46L2b_c Rick Graziani graziani@cabrillo.edu Rick Graziani graziani@cabrillo.edu 45 45

Computer is Hardware and Software Rick Graziani graziani@cabrillo.edu

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! Rick Graziani graziani@cabrillo.edu Rick Graziani graziani@cabrillo.edu 47 47

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… Rick Graziani graziani@cabrillo.edu Rick Graziani graziani@cabrillo.edu 48 48

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! Rick Graziani graziani@cabrillo.edu Rick Graziani graziani@cabrillo.edu 49 49

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.) Rick Graziani graziani@cabrillo.edu Rick Graziani graziani@cabrillo.edu 50 50

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 Rick Graziani graziani@cabrillo.edu Rick Graziani graziani@cabrillo.edu 51 51

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 Rick Graziani graziani@cabrillo.edu Rick Graziani graziani@cabrillo.edu 52 52

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 Rick Graziani graziani@cabrillo.edu Rick Graziani graziani@cabrillo.edu 53 53

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 Rick Graziani graziani@cabrillo.edu Rick Graziani graziani@cabrillo.edu 54 54

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. Rick Graziani graziani@cabrillo.edu Rick Graziani graziani@cabrillo.edu 55 55

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 Rick Graziani graziani@cabrillo.edu Rick Graziani graziani@cabrillo.edu 56 56

Operating System Software Software which manages the overall operation of the computer system including: hardware (CPU, RAM, I/O) security system interface application interface Rick Graziani graziani@cabrillo.edu Rick Graziani graziani@cabrillo.edu 57 57

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