CAS 133 – Basic Computer Skills/MS Office XP Russ Erdman

You've probably never heard of Ray Tomlinson, but odds are that you can't live without his invention. Ray Tomlinson, the inventor of

In late 1971, Tomlinson modified a computer file transfer protocol (FTP) to work with a simple mailbox program. He then sent the world's first message from one computer in his lab to another. The message caused the two-computer network to crash. From that beginning sprang a new form of communication that elevated an obscure symbol into a pop culture

sign seemed to make sense," Tomlinson says. "I used sign to indicate that the user was 'at' some other host [computer] rather than being local."

An engineer at Bolt Beranek and Newman (BBN) -- the company the U.S. government's Defense Advanced Research Projects Agency contracted in 1968 to develop DARPANET, which would later evolve into the Internet -- Tomlinson nearly suppressed his invention. One of his colleagues, Jerry Burchfiel, says Tomlinson cautioned him, "Don't tell anyone! This isn't what we're supposed to be working on!"

He didn't imagine that in less than 30 years, would go from being the preferred mode of communication of a few scientists around the U.S.A. to playing a key role in the daily lives of millions of people around the world, and even defining a generation

Ray Tomlinson developed the first application for the ARPANET, consisting of a program called SNDMSG for sending mail, and a program called READMAIL for reading mail. These early programs had simple functionality and were command line driven, but established the basic model still in use today.

How it Works:  Flo uses her software to write an . She includes the address and adds a Subject line.  She connects to her ISP (Internet Service Provider) and tells her software to send waiting messages.  The software sends the message to the ISP's sending software (SMTP server). That software checks that Flo is authorized to send through her ISP, looks at the address and sends the message on its way. Simple Mail Transfer Protocol, a protocol for sending e- mail messages between servers. Most systems that send mail over the Internet use SMTP to send messages from one server to another.

 After bouncing around the world a bit the message is received by my ISP's receiving software (POP server). Post Office Protocol, a protocol used to retrieve from a mail server. Most applications (sometimes called an e- mail client) use the POP protocol  That software checks that I'm "on the books" and drops the message in my letterbox on their machine.  At some point I start up my software, connect to my ISP and tell my software to look in my letterbox. My software has to tell my ISP's software who I am and what my password is before it can collect the mail. My software now downloads that message onto my computer and now I can disconnect from my ISP and sit back and read the message.

Step 1 Step 2 mail server Step 1 Step 2 Step 3 Internet routers mail server Step 1 Step 2 Step 3 Step 4 Internet routers mail server POP server How does an message travel? Step 1 Step 2 Step 3 Step 4 Step 5 Internet routers mail server POP3 server 1Create & send message 2Your software contacts ISP mail server 3Mail server determines best route 4Mail server transfers message to POP3 server 5When software checks for messages, message transfers from POP3 server to recipient’s computer

Snail mail used to be the only way to send a letter (FedEx and UPS gave them a run for their money) is now the most widely used Internet application. For some people, it is their most frequent form of communication. Neither snow nor rain nor heat nor gloom of night stays these couriers from the swift completion of their appointed rounds. - Herodotus, describing the Persian courier system about 500 B.C., inscribed on the General Post Office, New York City, U.S.A.

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