what is the history of data communication?
...losed--yielding 32 possible combinations. Each five-bit combination encoding a letter or symbol. As the brush arm moved in its circle it would pick up a code combination from one sector and then move on. As many messages as there were sectors could be sent simultaneously. Baudot modified the Morse code to meet the requirements of his invention. This five bit Baudot (character) code became the basis of all early 20th Century teleprinters.Murray also modified the original Baudot code and his modifications became the CCITT International Alphabet #2. This is the version of the Baudot code that was the grandfather of all modern character codes such as the ASCII code and IBM's EBCDIC code. This is how today's character code standards evolved. The Baudot code uses 5 bits to represent a character and does not include a parity check bit. 25 provides us with 32 unique codes, which was all that Baudot's multiplexer could handle. The Baudot code technology is also still used for some technologies used to communicate with the hearing impared. The standard continued to evolve within the constraints of the technological history. Baudot's code had considerable influence on the later design of communication devices and character codes. Changing to another code would have required redesigning everyone's equipment. To insure compatibility the early design and evolution of data commnications equipment was often standardized through the use of the Baudot code. In the mid-nineteenth century businesses hired telegraph operators to send messages using Morse Code, but the multiplexed teletypewriter using the Baudot code quickly replaced that technology. Teletypewriters (teletypes)[TTY] were machines that permitted the operator to type the message on a keyboard and have it automatically translated into the Baudot Code, and also to translate and print out incoming messages onto a roll of paper. The teletypewriters were connected to each other via telecommunication lines, and the application (the first business data communications application using electromagnetic switching) was called administrative message switching. Teletype technology is still used today in a variety of specialized areas, such as devices to assist the hearing impared. To set up these data communications applications, a company would connect headquarters with point-to-point links to its regional offices; each location would have a teletype machine. These were often strung out in series rather than as star topologies. That wasn't too efficient,But to those who used it at the time, it seemed ultra modern and fast. User expectations, like standards, also evolve over time. To improve on this state of communication affairs, a punched paper tape was invented. The Baudot code was represented by holes punched in a column. A teletype was designed that could print and read these paper tapes as well as print out the characters. If the message had to be forwarded, the paper tape was torn off one machine and sent on another connected to the next point-to-point link in this early network. In fact, the system was called the torn tape message system. Large companies maintained message centers--noisy rooms filled with teletypewriters and racks holding messages--the first store-and-forward facilities. Store-and-forward techniques are not obsolete--they are still the basis of all asynchronous message systems such as email. As communication technologies evolved, companies found it economical to try to develop line sharing facilities.For example, if a regional headquarters was opened in St. Louis, it might have to connect to corporate headquarters in New York and also to the Chicago office. Instead of obtaining a new line from St. Louis to New York, it would...