计算机科学本质来源于,计算机科学的本

计算机科学本质来源于,计算机科学的本"/>

计算机科学本质来源于,计算机科学的本

计算机科学的本-史元春

计算机科学的本质史元春清华大学计算机科学与技术系;Computing History is only;Mainframe Computing;－1946ENIACVon Neumann ComputerModern Computers; The Abacus The Mechanical Calculators The Electromechanical Machines;算盘数字由算珠的数量表示数位由算珠的位置确定 通过手动完成从低位到高位的数字传送(十进制)执行运算就是按照一定的规则移动算珠的位置;机械时代;机电时代;ENIAC：Electronic Numerical Integrator And Calculator (电子数字积分器和计算器) 1946，U Penn170m2，30 tons，150kwatts, 18800 vacuum tubes，5000 psThe first high speed general electronic computer;ENIAC的致命缺点：程序与计算两分离 指挥近2万电子管“开关”工作的程序指令，存放在机器的外部电路里。计算某个题目前，数十人用几小时甚至好几天把数百条线路用手接通，才能进行几分钟运算1946, Stored Program: EDVAC (electronic discrete variable automatic computer, 离散变量自动电子计算机)All computers more or less based on the same basic design;Model for designing and building computers, based on the following three characteristics:The computer consists of four main sub-systems:MemoryALU (Arithmetic/Logic Unit)Control UnitInput/Output System (I/O)Program is stored in memory during execution.Program instructions are executed sequentially.;Memory;von NeumannArchitecture;－1946ENIACVon Neumann ComputerModern Computers;First Four Generations;First Four Generations;History of Computing MachinesWhat we can learn from Moore’s LawFounders of Computing TheoryThe Essential Issue of Computer ScienceComputing as a Discipline

;What we can learn from Moore’s Law;What we can learn from Moore’s Law;Moore’s LawIntel’s 4004 (1971) to the present, the increasing of the number of transistors on its microprocessor fits it wellCPU leads the development of Computer Industry New Moore’s Law: Number of Internet Users doubles every 9 monthsThe same to data stream and bandwidth……;What we can learn from Moore’s Law;Microelectronictechnique RevolutionNow in LSI manufacture, 0.07μmIntel produce 65nm processor, 2006Panasonic produce 45nm LSI, 2007微电子工业发展的每下一步线宽约是前一步的0.7倍硅微集成电路的物理极限是10纳米纳米计算机、并行计算机、量子计算机Q: 摩尔定律是否像牛顿定律一样，是自然界不变的定律？;Inference from Moore’s Law计算机的高速发展“时间就是金钱”计算机的性价比永远在提高具有“自我强化”特征厂商需要不断改进性价比“过去无关