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Microprocessor Fundamentals Week 1 Mount Druitt College of TAFE Dept. Electrical Engineering 2008 Computers: where did they come from? Abacus: automated counting machine, lines drawn in sand with pebbles representing numbers, storage mechanism (memory), 2400 BC, Babylon First mechanical adding machine: Pascal 1642 Series of numbers entered and the wheels turned in the proper sequence gave a cumulative sum. Mechanical answer to arithmetic problems. Principle still in use today as water meters and odometers. Difference engine: steam powered, designed with repeated calculations in mind, never built. Had a fixed instruction program. Babbage, 1822 Analytical engine: storage of numbers (memory), included conditional operators (if statements) and instructions on punched cards (stored program). Babbage, 1833. Computers: where did they come from? (2) Hollerith and Tabulating Machine: used punched cards, eventually company became IBM. 1890. Binary numbers system – Zuse 1941. Allowed easy reading of cards, hole or no hole, 1 or 0. Complex calculations now possible to represent. Binary important to future design of computers using 2 state devices such as switches, card readers, vacuum tubes, semi conductors. Harvard Mark-1 – IBM, 1930. First large automatic calculating machine. Used punched cards, 23 decimal place numbers, could handle logs and trig function using in built programs. Used rotating wheels and relays ENIAC machine: Electrical Numerical Integrator and Computer - 1946, 18000 tubes, 167 square metres, first successful high speed digital computer The Von Neumann Machine Data same as program Early computers stored program in the control unit which had to be either rewired or changed if the program needed changing. If program is stored in same place as data then it can be changed similarly. Stored program concept Machine language applies this concept First machine to use it was in 1947 Computers: where did they come from? (3) EDVAC: Electronic Discrete Variable Automatic Computer, used Von Neumann’s concept Technology advances Transistor (1947): no more vacuum tubes Integrated circuit (1958): many transistors in one package Both of the above allowed computers to become smaller First microprocessor (1971): included ALU, control units, processed 4 bits of data Computers now available to general public BASIC First machine language: BASIC (1964): Kemeny & Kurtz. Beginners All-purpose Symbolic Instruction Code Gates & Allen used it to design an instruction set and compiler for the Altair machine. They sold it and Microsoft was born Languages FORTRAN: 1950s COBOL: 1960 PASCAL: late 1960s C: 1971 PC Explosion 1977: Apple 1981: PC 1984: 286 1983: lisa, first computer with mouse and graphical interface 1984: Macintosh 1980s: Commodore μProcessors