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Compared with modern devices like the iPhone and computer IPAD first glance very archaic. They were big, often with large custom built room to accommodate them, they were tender, large and air conditioners require constant cooling to continue to operate, and they were slow. The first system was only one task at a time and programs is necessary to handle to be directly fed into the system using punch cards, magnetic or paper tape.
As computer systems have developed and were better able efforts to make more efficient use of available computing power. Operating systems and technologies have been developed to allow multiple users access the host system from a convenient place both simultaneously and interactively. One such technology, the computer terminal.
Computer terminals are devices usually consists of a CRT monitor and a keyboard that was used to interact with a host system. Early terminals were called "Thank you" green screens "for monochrome displays worn very often phosphor screen by the majority of terminal screens. Another common nickname is" Dumb Terminal "in reference to the fact that the entire processing by the Host system has been treated and the real terminals could almost do nothing for himself. In fact, the host computer continuously check the connection to the terminal to determine whether an intervention by the user. This placed a great burden for the main unit of treatment with valuable computer time tour of the terminals, 40% of computer time available was spent not known. The largest installation, more users and devices, the more time had been wasted.
To solve this problem "intelligent terminals" have introduced dedicated IO (Input / Output) processing units. Terminal-Chip have been for her ability to handle the relatively simple processing at the local level, such as field validation of user input and can name the user to move a form to allow data to add. If the user has the terminal, the results of user intervention filled back to the host as a block of data. This block-mode terminals are also called intelligent terminals.
System manufacturers quickly realized they could more profitably by making their products unique and locking customers into their own products. The result is that each manufacturer has its own set of terminals, which were largely incompatible with the host system from someone else. The purchase of a mainframe including the need to buy compatible phones from the same manufacturer. As a result, in the 1960s and beyond, there were a relatively large number of different computer companies, each with their own unique and incompatible devices.
However, the late 1970s saw a reversal of this trend and the development of general-purpose machinery and standardized some of the new players in the IT industry, including Digital Equipment Corporation (DEC). These machines with a standard serial port, and standard character sets and "escape sequences" (commands were used to determine the form of text, layout and other display options on a terminal). It was much easier for other manufacturer’s devices and devices to a host system to connect.
Thank you for the most part to that openness and size of the market, for the connections of a number of companies were formed, whose sole activity was to terminals for connection to host systems produce made by others. These companies created terminals that connect a number of systems on the market and often have characteristics which have a cross between dumb terminals and intelligent, without the cost would have done the latter. Terminal manufacturers such as Tele Video sported highly desirable and unique functionality, software developers have to improve the advantage of their own applications. But software has become dependent on new material, but in this cases the terminal as the host system. (Software can run on different host systems, so long as the application could "worn").
Finally, in the modern era of the computer terminal has been replaced almost entirely by the ubiquitous PC and multi-functional. In the early days of PCs, it was common to a PC is sitting literally next to a computer terminal on the desktop of the user to find. However, it did not take long, this very poor use of valuable space on the desktop and the doubling of investment in the PC and the terminal has become a problem. The solution to this problem came in the form of a program that copies the space on the PC, taking the function of the terminal, the terminal emulator.
Terminal emulation software to stop the expenditure of the purchase and maintenance of terminals, with their close and special features. With a terminal emulator user, the system can directly from their home PC. Terminal Emulator software mimics the properties and behavior of various types of terminals and is available in versions that run a variety of devices in the modern workplace, such as a handheld computer, mobile phone or even via a browser. In many cases, the terminal emulation software with integrated word processing, spreadsheet, e-mail and so on and reduce the cost of access, while improving the capacity and present the user with a familiar user interface and modern Final older technology.
