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Chapter 9 - 1981 to 1995

Chapter 9 - 1981 to 1995. Workstations, UNIX & the Net. Next Step - Workstations. Inexpensive microprocessor Motorola 68000 Cost less than mini; more than PC Main Features UNIX Extensive Networking Capabilities Idea: Attach these to mainframe rather than dumb terminal.

jennifer-bolton
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Chapter 9 - 1981 to 1995

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  1. Chapter 9 - 1981 to 1995 Workstations, UNIX & the Net

  2. Next Step - Workstations • Inexpensive microprocessor • Motorola 68000 • Cost less than mini; more than PC • Main Features • UNIX • Extensive Networking Capabilities • Idea: Attach these to mainframe rather than dumb terminal

  3. Apollo - First Workstation • Bill Poduska, from Prime Computer • Domain: own OS and NW system • $40,000 • Used for CAD & engineering • Mid-1980 - sold 1,000 • 1989- bought by H.P.

  4. Sun Microsystems • 1982- founded by Vinod Khosla • Also Bill Joy • Stanford University Network Workstation • Andy Bechtolsheim • June 1982- SUN-2, $20,000 • Berkeley UNIX First Sun Workstation - 1983

  5. UNIX • AT&T Bell Labs, NJ; Ken Thompson, Dennis Richie • Not a complete OS • Set of tools to manipulate & share files • Due to legal actions • AT&T couldn’t sell for profit • Universities got license for cheap • Commercial could also buy • Open Source

  6. The UNIX Journey • Developed in New Jersey • To easily share files; Very frugal • Not for masses • Univ. of Illinois-Champagne-Urbana • U.C. Berkeley • Extensively rewritten • Bill Joy • Took it to SUN

  7. UNIX and Universities • Cheap source code • Written in C; run any machine with C compiler • Free to modify code - and they did • Berkeley Software Distribution (BSD) UNIX • 1978-Joy offering tapes cheap

  8. Universities (cont.) • 1980 - ARPA backed BSD • Version 4.2 • Network Protocol TCP/IP • ARPA promoted TCP/IP

  9. UNIX * Miscellaneous • VAX - Berkley UNIX w/ TCP/IP • Helped transform ARPANET to Internet • Vulnerable to viruses • Never really challenged Windows • Not even LINUX, yet

  10. Vax Strategy - 1980’s • Offer single architecture (VAX) with single OS (VMS) in solitary or networked configurations ranging from desktop to mainframe capability • Networking – Ethernet - from Intel & Xerox • “The network is the computer.” • Several Modes: 11/780, 11/750, MicroVAX II, 8600 (Venus), 9000

  11. Vax Strategy Risks • Similar to IBM’s “betting the company” • Had to supply customers with everything without seeming to change too much • Entire line had to be high in quality

  12. Risks (cont.) • Stop marketing its own competing H.W. • PDP-10- Outdated • Public outcry over PDP-10 & DECtape • Phase out an announcement • Historical Perspective- Pg. 186

  13. Vax Strategy Results • Did not stick with it • 1982 - 3 incompatible machines (not IBMPC compatible, either) • Strategy went well through 1980’s • 1987 stock market crash • Plus Competition from UNIX workstations and IMBPC • DEC couldn’t recover #2 position

  14. RISC • Reduced Instruction Set Computer • IBM-360, DEC VAX • Complex Instruction Set Computer (CISC) • 200+ instructions, each • Due to slow access core memory • Due to immature compilers • Trying to close “English Instruction” gap • Cheap ROM allowed low cost of CISC

  15. RISC- More #1 • John Cocke, IBM • Due to improved technology, believed smaller set of instructions with more loads and stores would be faster than 370 • Experimental: IBM 801, 1979 • Did not make market • 1980 - Berkeley- RISC Project • 1981- Stanford • MIPS (Millions of instructions per second) • Skepticism outside university environment • Everything else booming- so why change?

  16. RISC - More #2 • 1987- SUN SPARC- RISC Chip • Scalable Processor Architecture • Overcame Skepticism • RISC improved microprocessors speeds faster than mainframe & mini- processors were improving • Sun Licensed SPARC to others • Hoped it would become the standard • But would not be profitable

  17. RISC – More #2 (cont.) • MIPS computer systems • Stanford MIPS project • DEC bought RISC chip for workstation • Silicon Graphics • 1990- IBM R/6000 • 1990’s early: IBM & Apple • Power PC, Motorola Chip

  18. Workstation vs. PC • RISC Architecture • Scientific & Engineering Apps. • Networking (Ethernet) • Cost

  19. Ethernet • Developed @ Xerox PARC, 1973 • Robert Metcalfe & David Boggs • Metcalfe • At MIT in 1969- helped connect PDP-10 to ARPNET – to do same in ‘72 at PARC • Focus @ PARC was local networking • PARC Local Network • Data General minis in star technology • Expensive, inflexible, not robust

  20. ALOHAnet • To connect among Hawaiian Islands • Radio Signals  Wireless • Packets of 1000 bits; address of recipient attached to head of each message • Computers turned to UHF frequency & listened for packets

  21. Network Features #1 • Radio (medium) was passive • Computers (Nodes) did the work • Process, queue, route • “Ether”- invisible medium • Replaced by coaxial cable • New Computer just taps into cable

  22. Network Features #2 • Computer “listens” before sending • Collision: random pause, try again • If many collisions, send less frequently • Math analysis showed would work • 1974- Running @ 3 million bps • Arpanet 50 (telephone) - kilobits/sec

  23. Ethernet Impacts • Speed changed relationship between small and large computers • 1st affected workstations, then PC market • DEC, INTEL, Xerox: accepted as standard for VAX • DOS/ Early PC chips - not well suited for networking

  24. Apple  PC’s • With Lotus 1-2-3, Word Processing, and dBase III, IBM compatibles began to replace Apples and Word Processors in office environment • Less expensive clones

  25. “Personal” Computing in Business • Employees had personal SW • Not in line with business goals • Some sw not very good • Became problem for I.S. people • So LAN’s helped to “control” technology • Irony: networking made it not so personal

  26. Novell • Networking practical after 80386 • 1989 - had half business • Complex, expensive, overlaid DOS • File server with software • Not as good a UNIX networking with workstations • Backups, messaging, sharing

  27. Internet • LAN’s provided access to Internet • Key features • Descendent of ARPANET • Packet switching • No dedicated line necessary • TCP/ IP- standard protocol • Open to public, commercial

  28. Internet Success • ARPA’s support; adoption of TCP/IP in 1980 • TCP/IP inclusion into Berkeley UNIX • Not proprietary • Rise in number of LAN’s

  29. Success (cont.) • Ethernet Speeds • Grove’s Law • Telecommunication bandwidth doubles every 100 years • Cable, etc. have improved • “Last Mile Problem”

  30. Internet Before WWW • Arpanet- goal was resource sharing • FTP, Telnet: had to know location of information • Email - did emerge • Groups • Bulletin Boards, Discussion Groups, Etc. • Gopher- 1990/91 • Univ. of Minnesota • Search for Data on campus • Spread

  31. Before WWW (cont.) • WAIS - Wide Area Information System • Thinking Machines Corp., Cambridge • Searched documents & made index of words • All were short lived • But demonstrated what could be done

  32. WWW - The Beginning • Doug Englebart: mouse + on-line system, NLS • Vannevar Bush: 1945 paper - hypertext • Ted Nelson: Xanadu System • Computer Lib/Dream Machines • Hypertext: forms of writing which branch or perform on request; they are best presented on computer display screens • Worked on Xanadu during 70’s & 80’s • Apple Macintosh HyperCard - 1987

  33. WWW Finally • Tim Berners-Lee @ CERN • European particle physics lab • Swiss- French border • Features and Goals • A shared information space, inclusion • Across platforms • URL- Uniform Resource Locator • To avoid database restrictions • HTTP- to replace FTP • HTML

  34. WWW Early Years • Slow Start - few but CERN supported • Hard to program links • Just a few browsers- • Lynx & Viola

  35. Mosaic • Marc Andreessen & Eric Bina • U. of Illinois • January 1993- released Mosaic, a browser, over the Internet • Used Mouse, hypercard • Links in different color • Seamless integration of text and graphics • Re-written for Windows and Macintosh

  36. Netscape Navigator • 1994 – Jim Clark, Silicon Graphics • Commercialize Mosaic • Univ. of Illinois – objected • Andreessen had been a student there • Clark & Andreessen • Netscape Communications Corp • Mosaic died • 1995 – Public release of stock • $28  $58 (day 1)  $150

  37. Chapter 91981-1995 Workstations, UNIX & the Net

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