Appendix The Continuing Story of the Computer Age

Early Calculating Devices n abacus - calculating device used for about 4000 years throughout the ancient world n quipa - used by Incans to represent data (e.g. payments, memorable dates) abacus quipa

Steps Toward Modern Computing n Jacquard’s loom - patterns for the loom could be “programmed” (punch cards)

Charles Babbage n English mathematician and scientist ( ) n nicknamed “father of computing” n Difference and Analytical Engines were direct predecessors of modern computers n worked with Lady Ada Lovelace (first programmer) Difference engine

Herman Hollerith n invented a tabulating device used for compiling the 1890 census –introduced the idea of automated data processing –continued developing business machinery –his company was one of the companies that joined to form IBM

The start of modern computing n ENIAC - first large-scale electronic digital computer (completed in 1946) –built by John Mauchly and J. Presper Eckert at the University of Pennsylvania –17,480 vacuum tubes, 30 tons, 10’ high, 3’ wide, 100’ long –had to be rewired to change program

Other Early Developments n stored program concept –programs and data stored in the computer’s memory –developed by John von Neumann n Grace Murray Hopper –developed some of the first high-level programming languages

1st Generation Computers - ( ) n used vacuum tubes - very unreliable n machine language programming n punched cards and magnetic tape n UNIVAC completed in 1951 –first computer built for commercial use –purchased by the U.S. Census Bureau

2nd Generation Computers - ( ) n transistors replaced vacuum tubes n faster, smaller, and more reliable than 1st generation machines n used punched cards, printers, tape and disk storage n development of assembly languages and first high-level languages n computers used principally by businesses

3rd Generation Computers - ( ) n integrated circuit (IC) - a complete electronic circuit on a chip of silicon n replaced transistors in computers - faster, smaller, less expensive than earlier machines n “computer families” introduced n unbundling of software - separate the selling of software and hardware n standards developed for computer networks (Internet begins)

4th Generation Computers - (1971-Present) n extension of IC technology led to VLSI n development of the microprocessor n introduction of personal computers and supercomputers –Apple Computers (1977) –IBM PC (1981) - non-proprietary parts Microsoft provided original OS n proliferation of application software n GUI’s become widely used n proliferation of networking (Internet, WWW)