The History of Networking
Lecture Notes 9/9/2002 by Aletha Green

I. Pre-networked computers (1940’s- 1950)

# First Electrical Computer

-University of Penn, 1945 ENIAC (Electronical Numerical Integration Analyzer and Computer)

-Most important invention by the allies for WWII to calculate ballistic tables

-80,000 hours of run time at 30 seconds at time (ten years)

# First Commercial Mainframe Computer

-1953 IBM (IBM 701)

-based on concept of batch processing

-usually on a punch card or paper tape , load cards into computer, executed the commands on the card

-cards in, print out (on green bar paper)

-turnaround time (minimum one day, could be longer) how long you wait to receive the info

-any mistake in the program, punch card anything…program will blow up, do a “dump”. Binary code that the programmer will have to interpret

-LOOM (punching cards made a certain pattern on the fabric) makes fabric was the inspiration for a computer, punched cards

-Charles Babbage invented a mechanical computer, the concept

# The Birth of the Data Processing Department

-Accounting, Payroll, Inventory control. Things large company’s had to do, that’s why they loved mainframes (get rid of people and save money). More effective than people (doesn’t make simple mistakes). Mainframe doesn’t get tired, no training involved.

-the person in front of the window was the first user interface

II. Baby mainframes (1960’s)

# Birth of the Mini Computer

-Used mainframe for accounting, payroll, inventory control but the other departments had smaller mini computers.

-Didn’t require special cooling, housing, electricity (file cabinet size), knowledge, care and feeding.

-people with the mainframe became less important because you didn’t have to deal with them, you could do it yourself.

-first example of losing central control of computing

-used to teach people to teach conceptual mathematics

-UNIX came up with mini computers as an operating system

# Time Sharing

-makes it look like you’re the only one using the computer but actually, there are many people on the system. Many people are able to use the system.

III. Early network development

# Islands of Automation

-couldn’t communicate with other computers

-IBM developed a protocol (language) called SNA (SYSTEM NETWORK ARCHITECTURE).SNA was used to communicate from IBM mainframe to IBM mainframe. Still used today.

#Propriety Networking

-no need to share information with a “non” IBM computer. This inability to communicate to DEC mini computer (second most popular computer) and IBM is Propriety

#The Need for Standards

-During the 1960’s the government asked computer vendors to develop hardware and software to allow computers to share information with each other.

- The Government was using mainframe computers and mini computer in many agencies. The General Accounting Office (GAO) found that some federal computers were overwhelmed while others were hardly working!

-DOD (Department of Defense encouraged vendors that did business with them to develop standards so that Government, Educational, Research and DOD computer could communicate using existing telephone lines. Trade information between universities etc.

-Program ARPANET (advanced research project agency network) is the precursor of today’s internet. TCP IP (protocol) was established.

IV. Rise of the Personal Computer (1970’s)

# Early Microprocessors

-used in microwaves, refrigerators, dishwashers

# Apple enters the scene

-1976 invented a computer in a garage Steve Wozniak and Steve Jobs

-responsible for early pc revolution (make computers personal)

-first popular program to run on Apple computer was Visacalc ( invented by Harvard business students)

# IBM and the early IBM-PC

-August 1981 the computer we know today was developed by IBM.

-contracted with startup company Microsoft who developed program called MS-DOS

V. Early PC Computing (1980’s)

# The Need to Connect

# Sneaker Net

-walk a floppy to a co-workers desk to share information

-Inconvenient, inefficient

-The need to share information between computers is the main reason for

computer networks

# Data Switches

-switch boxes (before network) used to share a peripheral device (ex: printer, modem)

-problem, you have to remember to switch the switch

-problem, can’t use simultaneously, no queuing capability

#Disk Servers

-first attempt at “file serving”

-a group of pc’s connected in some way to other pc’s that is running a special program that is designed to handle file and print requests

-PROBLEM, once you connect to the host, you’re the only person who can use it, either total or NO control (no better than a/b switch)

-PROBLEM can’t file or record lock (doesn’t allow for read only file, last person who saves wins)