1 - Early Computing and 2 - Electronic Computing

CS 1 Notes 1 - Early Computing and 2 - Electronic Computing

Computer Science: The discipline that seeks to build a scientific foundation for such topics as: – computer design – computer programming – information processing – ______

A ______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 ____different states (______)

Role of Algorithms

Algorithm: A ______that defines how a task is performed Program: A representation of an ______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.

Early examples of algorithms – Long division algorithm – Euclidean Algorithm

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

1 Early computing devices – ______: positions of beads represent numbers – ______(1600s-1800s) • Positions of gears represent numbers • Blaise Pascal, Wilhelm Leibniz, Charles Babbage

Babbage’s Difference Engine

• 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)

Augusta Ada, 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 "______". The computer language Ada, created by the U.S. Defense Department, was named after Ada Lovelace.

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

The Jacquard loom was the first machine to use ______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)

First Generation – ______

The brains of early electronic computers were ______or mechanical switches.

The control wire determines whether the circuit is ______. Mechanical Relays

2 When current flows through the coil, an electromagnetic field is created, which attracts the metal arm inside the relay, snapping it shut and ….. …. completing the circuit.

3 Disadvantage is the arm has “mass” which makes it ______.

About ______times per second Not fast enough for solving large computational problems ______

Needed a faster, more reliable alternative to mechanical relays.

Second Generation – ______

1904 – John Ambrose Fleming invented the thermionic valve (vacuum tube). Later, developed as an electronic switch… ______! Switched ______of times per second

1930’s – Vacuum tubes were used as electronic circuits or ______. Second Generation – Vacuum Tubes

The ______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 ______. Used thermionic valves (vacuum tubes) for the high speed circuits

1946 - ENIAC First large-scale electronic digital computer was ______(Electronic Numerical Integrator and Calculator) First truly general purpose computer 30 feet long, 8 feet wide, and 8 feet high ______additions every second, (incredibly slow by today’s standards). Vacuum tube failures common

______, one of the first programmers on the Mark-I and the ENAIC. She was the developer of the programming language ______, 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!

Third Generation – ______

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 ______Can switch 10,000 times per second Third Generation - Transistors

4 Transistors were: ______

IBM 608 and 360 1957 - IBM 608 – First fully transistorized computer 3,000 transistors 4,500 additions per second

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”

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.”

1960 – IBM 360 1 addition every billionth of a second (nanosecond), or a billion additions every second

ICs, chips, were: Smaller Faster More reliable Less expensive

Fifth Generation - ______A microprocessor is a Central Processing Unit (CPU) on a single chip. 1971, ______introduced the first microprocessor chip. – Intel 4004 108 kHz and contained (equivalent of) 2300 transistors

5 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.

1975 - Altair 8800 Ed Roberts and the first microcomputer or personal computer (for the consumer) the Altair 8800 MITS Altair 8800

Microcomputer - a computer which has a microprocessor. Used the Intel 8080 Microprocessor Microprocessors Personal Computers Computer Basics 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 Special Purpose Computers

Special purpose or dedicated computers – A device with a specific purpose such as game system or information kiosk. Computer is Hardware and Software

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! 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.

6 The Processor: The CPU

CPU (Central Processing Unit) = A complex collection of electronic circuits on one or more integrated circuits (chips) which: 1. ______2. communicates with other parts of the computer system, especially RAM and input devices

The CPU is the computer! RAM (Random Access Memory)

RAM (Random Access Memory) = integrated circuits (chips) used to ______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.)

RAM is ______memory RAM is ______stores ON and OFF bits (software and data) electrically when power goes off, everything in RAM is lost

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

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 ______Cannot be ______Cannot be appended (added to) Fixed by manufacturer 7 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

______= software program which is stored permanently on a microchip, such as the software on the ROM chip 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.

Operating System Software

Loads automatically when you switch on a computer Main roles: – Controls ______– Permits you to ______– Acts as intermediary between user and applications

Software which manages the overall operation of the computer system including: hardware (CPU, RAM, I/O) security system interface application interface