Chapter 1 電腦是什麼時候發展出來的?

大約一千三百多年前…

「電腦」是什麼? A device that computes, especially a programmable electronic machine that performs high-speed mathematical or logical operations or that assembles, stores, correlates, or otherwise processes information -- The American Heritage Dictionary of the English Language, 4th Edition, 2000 Many computing devices have been developed: Special-purpose versus general-purpose Non-programmable versus programmable􀁺 Mechanical, electromechanical, electronic, …

第一部 全電子式 可程式 一般用途的電腦 是什麼時候發展出來的?

第一部「電」腦 一般認為：ENIAC (Electronic Numerical Integrator and Calculator) Work started in 1943 in the Moore School of Electrical Engineering at the University of Pennsylvania, by John Mauchly and J. Presper Eckert 在二次世界大戰期間運作 1946年公諸於世 約25公尺長、2.5公尺高 20 10-digit registers, each 2 feet 使用18,000個真空管 (electronic switches) 每秒執行1900個加法 Programming manually by plugging cables and setting switches

大約同一時期，人們發明了電晶體 By W. Shockley, J. Bardeen, W. Brattain of Bell Lab. in 1947 Much more reliable than vacuum tubes Electronic switches in “solids”

不久後使用電晶體的電腦出現 1950 年代 中期

電腦元件的另一大突破是IC 1958年德州儀器公司的Jack Kilby: integrated a transistor with resistors and capacitors on a single semiconductor chip, which is a monolithic IC

當更多的電晶體能放入IC後... 1971年第一個微處理器：Intel 4004 108 KHz, 0.06 MIPS 2300 transistors (10 microns) Bus width: 4 bits Memory: 640 bytes For Busicom calculator

微處理器造就了... 1977年Apple II: Steve Jobs, Steve Wozniak

以及PC 1981年IBM PC: Intel 8088, 4.77MHz

一些週邊設備也早已發展出來 1973: Researchers at Xerox PARC developed an experimental PC: Alto 􀁺 Used mouse, Ethernet, bit-mapped graphics, icons, menus, WYSIWG editing Hosted the invention of: 􀁺 Local-area networking 􀁺 Laser printing 􀁺 All of modern client / server distributed computing

讓PC成為真正有用的東西--應用程式 1979: 1st electronic spreadsheet (VisiCalc for Apple II) by Don Bricklin and Bob Franston “The kill app for early PCs” Followed by dBASE II, ...

人們也先後發展出許多其他東西...

80年代，IC的集成進入VLSI New processor architecture was introduced: RISC (Reduced Instruction Set Computer) IBM: John Cocke UC Berkeley: David Patterson Stanford: John Hennessy Commercial RISC processors introduced around 1985 􀁺 MIPS: MIPS Sun : Sparc IBM : Power RISC HP : PA-RISC DEC : Alpha They compete with CISC (complex instruction set computer) processors, mainly Intel x86 processors, for the next 15 years

Let’s Start with Processor Performance

Why Such Changes? Several factors: IC technology: clock rate, power, transistors per chip ⇓ enable Computer architecture: pipeline, cache, MMX, instructions per cycle ⇓ supported by Mass market: market share, revenue, applications

VLSI IC Technology cost per transistor↓ chip density↑

Technology Trends: Memory Capacity (1 Chip DRAM) year size(Mbit) 1980 0.0625 1983 0.25 1986 1 1989 4 1992 16 1996 64 2000 256 1.4X/yr, or doubling every 2 years 4000X since 1980

Technology Trends: Microprocessor Capacity

Technology => Dramatic Change Processor 2X in speed every 1.5 years; 100X in last decade Memory DRAM capacity: 2x / 2 years; 64X size in last decade 􀁺 Cost per bit: improves about 25% per year Disk 􀁺 Capacity: > 2X every year; 120X in last decade 􀁺 Cost per bit: improves about 100% per year State-of-the-art PC when you graduate: 􀁺 Processor clock: 4.0 GHz 􀁺 Memory capacity: 1.0 GBytes 􀁺 Disk capacity: 1.0 TeraBytes New units! Mega => Giga, Giga => Tera

Summary Computer architecture studies instruction set architecture and computer organization Instruction set architecture is about interface All computers consist of five components: Processor: (1) datapath and (2) control (3) Memory (4) Input devices and (5) output devices Architecture design is an iterative process; must consider: 􀁺 Device technology Application and market Performance evaluation