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William Oughtred –slide rule Wilhelm Schickard- mechanical calculator (1623) Blaise Pascal-decimal calculator Leibniz-“Stepped Reckoner”, full-featured calculator, binary system Charles Babbage-designed two mechanical computers controlled by punched cards -Difference Machine and Analytical Engine Ge...

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William Oughtred –slide rule Wilhelm Schickard- mechanical calculator (1623) Blaise Pascal-decimal calculator Leibniz-“Stepped Reckoner”, full-featured calculator, binary system Charles Babbage-designed two mechanical computers controlled by punched cards -Difference Machine and Analytical Engine George Boole- “Booelan Algebra” and “Invariant Theory” (used in Einstein’s theory of relativity) -laid logical foundation of digital computing circuitry Ada Lovelace-wrote programs for it (Analytical Engine) (first programmer) Thompson-The “Differential Analyser” was invented in 1876 but actually built by Vanevar Bush in 1930 Atanasoff-Berry machine (first electronic proto-computer, using vacuum tubes for calculations, capacitors for memory, and binary arithmetic, but it only had one purpose: to solve linear algebraic equations) and the Zuse. -design was stolen by Mauchly, who with Eckert built the ENIAC (in 1945), falsely claimed to be the first US computer Claude Shannon 1937-introduced application of Boolean Logic in creating digital computing machines 1948-published “a mathematical theory of communication” which establishes the principles for encoding information so it might be reliably transmitted electronically -considered the father of the modern information age Alan Turing- Led the World War II research group that broke the code for the Enigma machine (1918) -Proposed a simple abstract universal machine model for defining computability – The Turing Machine -Devised the “Turing Test” for Artificial Intelligence - constructed an electronic computing machine in 1943 to help decrypt German coded messages (Colossus; designed by Flowers and Newman) Z3 (1941): the first programmable, Turing complete computer used telephone relay switches (instead of electronic vacuum tubes) by Konrad Zuse. Using relays; it was the first ever general purpose programcontrolled calculator or computer, although not electronic IBM Automatic Sequence Controlled Calculator (ASCC), installed at Harvard University in 1944 • ENIAC (1945): Electronic Numerical Integrator And Computer is the first general-purpose electronic digital computer, commissioned by the United States Army for computing ballistic firing tables. Mauchly and Eckert • Noted for massive scale and redundant design • Used vacuum tubes to control the flow of electrical signals • Decimal internal coding • Operational in 1946

Neumann- Prepares a draft report for an automatic programmable device (later called EDVAC) - Comes up with the “stored program” concept - Designs the IAS (Institute for Advanced Studies) machine which becomes operational in 1951 Von Neumann Architecture- “stored program” - Binary internal coding, CPU-Memory-I/O organization, “fetch-decodeexecute” instruction cycle Univac I: First commercial general-purpose computer (delivered in 1951) - Used to forecast the 1952 United States presidential election Grace Murray Hopper- Created first Compiler because she was tired of writing machine code by hand. Greatly improved programming speed and efficiency. -The transistor (most important invention) - invented by Shockley, Bardeen & Brattain in 1947 at Bell Labs, replaced vacuum tubes, which were bulky - Integrated Circuit invented by Jack Kilby in 1958, allowed placement of many transistors onto a small surface, this enabled computers and other electronic devices to become smaller and cheaper to build and maintain -1948-1955 most of the computers designed used vacuum tubes, in which electrodes control the flow of electrons. Later designs started to use “semi-conductors” or solid state devices, eventually based on silicon. - The first fully electronic, stored-program machine, the prototype Manchester Mark I, ran on 21 JUNE 1948 Hearing aid- The first device built with transistors, in 1953 - Zenith Royal-T “tubeless” hearing aid -then transistor radio The Integrated Circuit (IC)- Invented by Jack Kilby at Texas Instruments in 1957, -Enabled many transistors to be grouped into a single package, -Lowered cost and decreased space compared to using individual transistors - First commercial use of the IC was in a pocket calculator in 1961 IBM System/360- Introduced in 1964 -first IBM “real” computer was the 701 -Apollo space program depended on computers to calculate trajectories and control guidance -Trajectories calculated using IBM mainframes -Onboard guidance computer had less processing power than modern appliances, but had auto-pilot capabilities Margaret Hamilton - Led the team who coded programming for the guidance computer - Considered a pioneer in software engineering

IBM- Known for commercializing early computing machines (1890s), mainframe computers (1960s), and modern servers (present) - Lynn Conway - 1964: designed supercomputer architecture on the Advanced Computing Systems project -1968: transitioned and started new identity -Later joined Xerox PARC, wrote defining textbook on chip design

Gordon Bell: the “Minicomputer” Digital Equipment Corporation (DEC)- Developed first “mini” computers, 1960-83 - Brought computing to small business, created major competition for IBM, Univac, who only built mainframes - Made Boston area first “silicon valley” DEC PDP series- Offered mainframe performance at a fraction of the cost - PDP-8 introduced at $20,000 vs. $1M for a mainframe Specialized Supercomputers- First developed in the late 1970s - High-performance systems used for scientific applications (weather forecasting, code breaking) - Cray Research, Control Data, NEC, IBM and others

Age of the Personal Computer - Intel 4004 Microprocessor – 1972 - First commercially available microprocessor – first used in a programmable calculator - Made the personal computer possible - Contained 2300 transistors and ran at 100 kHz - Desktop and Portable Computers 1975 and later Desktop and Portable Computers 1975 and later - use microprocessors - all-in-one designs, performance/price tradeoffs, aimed at mass audience, personal computers, workstations -Altair 8080 first kit micro computer (1975) -Radio Shack TRS-80 (1978) -first plug and play personal computer available at retail -programmed in BASIC Apple II (1978)- first commercially available Apple -initially sold to Wall St. bankers who wanted the spreadsheet program called Visicalc, which ran on the Apple II

Osborne I (1981)- First “portable” personal computer

IBM PC (1982)- IBM’s first personal computer - Operating System supplied by Microsoft

Xerox Palo Alto Research Center (PARC) -Contributions to computing include: - Ethernet networking technology - Laser printers/copiers - Object-oriented programming (OOP) paradigm - Workstations Alto and Star were the first to use a window-based Graphical User Interface (GUI) Adele Goldberg -Contributed to development of OOP language Smalltalk-80 and the Alto and Star GUI Apple MacIntosh (1984)- second Personal computer with GUI interface - adapted from the work done at Xerox - introduced at the 1984 Superbowl Advanced Research Projects Agency Network (ARPANET)- Large-area computer network, established in 1969 -Communication protocols developed for ARPANET in early 1980s served as the basis for the Internet -Ginny Strazisar -Co-wrote the program to direct information along ARPANET Mobile Computing-Popularized in ‘90s with the personal digital assistant (PDA) -Market leader in PDAs was Palm Computing - Donna Dubinsky - Founding CEO of Palm Computing - Helped develop PalmPilot, the first commercially successful PDA The first semi-conductor transistor came to life on 23 Dec.1947 at Bell Labs

Today’s Price/Performance - Over 3 billion operations per second costs less than $300 - Memory is measured in Gigabytes… not Megabytes or Kilobytes - Secondary Storage is Terabytes, soon to be Petabytes - Communication speeds measured in Megabits or Gigabits per second, not Kilobits

REPRESENTING TEXT -First 32 are control characters (or hidden characters); they control how text appears, but do not appear as text

-Decimal Arabic numbers (i.e., 0, 1, 2, etc.) start at code 48 - E.g., the code for 6 is 48 + 6 = 54 (48=0, 49=1….) -Uppercase Roman letters (i.e., A, B, C, etc.) start 65 -E.g., the code for J (10th letter) is 65 + (10 – 1) = 74 (65=A, 66=B…) - Lowercase Roman letters (i.e., a, b, c, etc.) start at 97 - E.g., the code for j (10th letter) is 97+ (10 – 1) = 106 (97=a, 98=b)

48=0 65=A 97=a Data compression is a reduction in the amount of space needed to store a piece of data. Compression ratio is the size of the compressed data divided by the size of the original data.

A data compression technique can be -lossless, which means the data can be retrieved without any loss of the original information -lossy, which means some information may be lost in the process of compaction...