A Short History of Computers

Transcription

1 A Short History of Computers Geoffrey M. Rockwell x Togo Salmon 309A grockwel@mcmaster.ca URL: McMaster University

2 Administration u Homework 3 is up. Complete by next Wednesday.

3 Review - Types of Storage Storage Permanent Temporary Removable Fixed RAM ROM Hard Drive Floppy CD-ROM Magneto-Optical Storage typically measured in K (Kilobytes), MB (Megabytes) or GB (Gigabytes)

4 Storage (bits and bytes) Kbps = Kilobits per second Computer is digital. Information has to be digitized. (binary digits) Bits and Bytes Bit - 0 or 1/On or Off/ Byte - Eight Bits K (Kilobyte) 1024 bytes MB (Megabyte) about 1000 K GB (Gigabyte) about 1000 MB Number Binary Letter ASCII A B

5 Review - From letters to bytes A 1 Byte Laser (8 Bits) off.on.off.off.off.off.off.on CD-ROM Floppy Disk

6 Brief History of Computing u Prehistory - Babbage and Lovelace u The first computer? - ENIAC u The first home computer? - Altair u Accessible computing - Apple u Micros go business - IBM PC

7 Babbage and Lovelace u Charles Babbage ( ) u Difference Engine 1833 u 1835 Analytical Engine uprogrammable (Cards) umechanical u Ada Lovelace It weaves algebraic patterns just as the Jacquard loom weaves flowers and leaves (Ada Lovelace) Gibson - The Difference Engine

8 ENIAC u Mauchly and Eckert proposal to Army u ENIAC (Electronic Numerical Integrator and Computer) working in 1945 (after the war) u von Neumann - EDVAC u Transistor invented in 1947 u ICs - Integrated Circuits u Microprocessor (Intel 4004) 1971 Printer

9 ENIAC Pictures Programming with switches Engineers The initiating and cycling units of ENIAC

10 Altair - the Microcomputer u MITS - Altair u Uses the Intel 8080 u Cover of Popular Electronics ujan u MITS hires Allen (and Gates)

11 Apple u Steve Wozniak (the Woz) u Steven Jobs u Homebrew Computer Club u Apple I - MOS 6502 chip u 1976 Mike Markkula bought in uapple Founded u 1977 the Apple II u 1984 the Macintosh

12 IBM PC u Built on the Intel 8088 u Operating System from Microsoft (and others) u Put together with existing components u Open to cards and software u Released in 1981 An IBM Clone

13 Key Innovations u Calculating device u General Purpose Device - Programmability u Digital Device u Electrical Device u Integrated Circuits - Transistors u Interface from Commands to GUI u Multiuser/Shared Computer to Personal Computer

14 History of the Net u Sputnik and The Space Race u ARPA and the ARPANET u and the subversion of the Net u Who has access, really?

15 Birth of the Internet u Sputnik u Advanced Research Project Agency u RFP for Interface Message Processors (IMPs) u UCLA and SRI connected in 1969 IMP

16 Evolution of the Internet u Ethernet - Bob Metcalfe u ARPANET splits off MILNET nodes, 45 go to ARPANET u TCP/IP , ARPANET switches in 1983 u ARPANET replaced by NSF backbone

17 History of and Web u MAILBOX on MIT time-sharing system, early 1960s u Ray Tomlinson - MAIL symbol u 3/4 of ARPANET traffic is in 1973 u World Wide Web utim Berners-Lee, CERN u Netscape. Netscape Corp is traded on the stock market.

18 Internet Census

19 Current State of the Net Who has access? Who doesn t?

20 How do computers change communication??

21 How do computers change communication? u Networks change how we communicate u Internet, , WWW, Chat, MUDs, IRC u Computers change what we communicate u Multimedia, Procedures, Agents u Networks change where we communicate u Home Office, Virtual Spaces u Networks change when we communicate u Asynchronos Communication, Chat u Networks change the pace of communication

22 What is a computer network? A system of computers interconnected by telephone wires or other means in order to share information. Also called a net. u Physical Layer - Cables, Routers, NIC (Cards) u Software Layer - Protocols and Packets u Service Layer - WWW, , Gopher

23 LANs u Local Area Network Cable Network Cards Personal Computers Networked Devices File Server Net Printer Shared Devices

24 WANs u Wide Area Network Internet (US nets) CAnet (Canada Wide) Onet (Ontario Wide) McMaster Backbone Other Universities Togo Salmon LAN Other Buildings

25 Movement of Information Packets 1. Your file is divided into lots of small packets. 2. The packets are addressed. 3. The packets are sent out. IP = From: and To: TCP = How many packets, order Information 4. Packets are reassembled into a file

26 What can you do with network? u Share a Program u Share a File Server u Swap Files (FTP, P2P) u Send Electronic Mail u Join Discussion Groups Application Server File Server Server List Server (Listserv) u Publish and Read Information (Gopher, WWW) WWW Server u Chat (IRC, MSN Messenger)

27 What is the Internet u internet = a network of networks u Internet = the web of academic and commercial networks that use the TCP/IP protocol u Transmission Control Protocol / Internet Protocol u The Infobahn (Transport vs Service) u A culture or place for subcultures to form

28 Wireless Culture

29 Teddy Bear Hoax Hi Everyone, I just got this message from one of my friends. Sure enough my address book was infected, which means yours will be also. The virus (called jdbgmgr.exe) is not detected by Norton or McAfee anti-virus systems. The virus sits quietly for 14 days before damaging the system. It's sent automatically by the messenger and by the Address Book, whether or not you sent s to your contacts. I have checked, found it, and deleted it.

30 What will you be able to do on the Internet??

31 What will you be able to do on the Internet? u Subscribe to multimedia information (video on demand) u Play Collaborative games (collaborative work) u Buy things - Conduct secure financial transactions u Send out Agents to do tasks like booking a flight. u Chat and videoconference u Remote sensing u Distributed computing (Where will your PC go?)

32 End