Teleprinter

A teletypewriter also referred to as a teletype machine is a now largely obsolete electro mechanical typewriter that was used to communication typed messages from point to point through a simple electrical communication channel. 

 A predecessor to the teletypewriter was the stock ticker system , which was developed in the 1870s as a method data over long distance  telegraph lines and displaying the data in alphanumeric characters. The system employed a specially designed telegraph typewriter on one end and tickers, which printed stock quotes on the other end. 

Most tele type writers used the five bit baudot code which was devised around 1875 by a frenchman named email baudot. The five bits limited the character set to 32 codes , but a FIGS  ( e.g. figures snift) shift key enabled it to also type numbers and special characyers . sprcialized versions had FIGS code for specific applications such as specific applications such as wnether reports. The quality of the printing was poor by current standards. 

Many teletype machines were linked to, or had built in paper tape punching and reading machines , thus allowing messages to be created and edited off line as well as stored and retransmitted on other circmits. complex military and commercial communications networks where constructed which had centres with rows of teletypewrites and large racks for papaer tapes awaiting transmission. skilled operators could determine the priorities of message directly from the tapes and could thus load a priority tape into another machine for retransmission while it was still coming out of the punching unit. 

* Advantage of teleprinter.It is a telegraph transmitting receiving machine. 

It resembles a typewriter because it has a type writer  like keyboard 

It is a machenical device driven by electrical motors. recently, electronic machine has been inctroduce confrolled by the microcessor code used by telaprinter machine is the 5 unit code . It works on the start stop principle a teleprinter acts both as a transmitter and a receiver. 

When used as a receiver the signals are received in the serial from are converted into parallel . Then a defector converted it into the cnoracter and the printer prints it on the paper. 

It has also the facility of local record. Principle . It acts both as a transmitter and as a receiver when used as a resiver, the signals areresiver in the serial from are converted it into the character and the printer prints it on the paper. 

Every teleprinter has also the facility of local record , the actual mechanical arrangement ofa teleprinter machine is very complicated but a block diagram is shown in the figure . Which shows the  different parts of the machine. The teleprinter is basically used for sending and recieving of telegraph signals , teleprinter switching