A Short History of Computers Geoffrey M. Rockwell x 24072 Togo Salmon 309A grockwel@mcmaster.ca URL: http://www.humanities.mcmaster.ca/~hccrs/ihchome.htm McMaster University
Administration u Homework 3 is up. Complete by next Wednesday.
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)
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 00110011 K (Kilobyte) 1024 bytes MB (Megabyte) about 1000 K GB (Gigabyte) about 1000 MB Number Binary 0 0 1 1 2 10 3 11 4 100 5 101 Letter ASCII A 01000001 B 01000010
Review - From letters to bytes A 1 Byte 01000001 Laser (8 Bits) off.on.off.off.off.off.off.on CD-ROM Floppy Disk
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
Babbage and Lovelace u Charles Babbage (1791-1871) 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
ENIAC u Mauchly and Eckert - 1943 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
ENIAC Pictures Programming with switches Engineers The initiating and cycling units of ENIAC
Altair - the Microcomputer u MITS - Altair u Uses the Intel 8080 u Cover of Popular Electronics ujan. 1975 u MITS hires Allen (and Gates)
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
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
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
History of the Net u Sputnik and The Space Race u ARPA and the ARPANET u E-Mail and the subversion of the Net u Who has access, really?
Birth of the Internet u Sputnik - 1957 u Advanced Research Project Agency - 1958 u RFP for Interface Message Processors (IMPs) - 1968 u UCLA and SRI connected in 1969 IMP
Evolution of the Internet u Ethernet - Bob Metcalfe - 1973 u ARPANET splits off MILNET - 1983 113 nodes, 45 go to ARPANET u TCP/IP - 1978, ARPANET switches in 1983 u ARPANET replaced by NSF backbone - 1985
History of E-mail and Web u MAILBOX on MIT time-sharing system, early 1960s u Ray Tomlinson - MAIL - @ symbol - 1972 u 3/4 of ARPANET traffic is e-mail in 1973 u 1990 - World Wide Web utim Berners-Lee, CERN u 1995 - Netscape. Netscape Corp is traded on the stock market.
Internet Census 1997 1991
Current State of the Net Who has access? Who doesn t?
How do computers change communication??
How do computers change communication? u Networks change how we communicate u Internet, E-mail, 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
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, E-mail, Gopher
LANs u Local Area Network Cable Network Cards Personal Computers Networked Devices File Server Net Printer Shared Devices
WANs u Wide Area Network Internet (US nets) CAnet (Canada Wide) Onet (Ontario Wide) McMaster Backbone Other Universities Togo Salmon LAN Other Buildings
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
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 E-mail Server List Server (Listserv) u Publish and Read Information (Gopher, WWW) WWW Server u Chat (IRC, MSN Messenger)
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
Wireless Culture
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 e-mails to your contacts. I have checked, found it, and deleted it.
What will you be able to do on the Internet??
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?)
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