![]() Destination/source ID consisted of four fields: Twenty four characters were used for source/destination ids, 14 characters for date and time stamp, and 7 characters for document reference which also specified the number of pages in the document. ![]() The header information consisted of four parts: Telex procedures called for the exchange of header information before the actual document transfer took place. The teletex would also maintain compatibility with the present telex system and inter-operate with it. In other words, a user might be preparing a new document, while another document was being transmitted or received. Transmission/reception of messages should proceed in the background without affecting the work which the user might be carrying out in the foreground with the equipment. The page control feature allowed standard A4 size papers to be used for receiving messages instead of the continuous stationery used in conventional telex systems.Ī background/foreground operation was envisaged in teletex. In particular, they permitted the positioning of the printing element, specification of page orientation, left and right margins, vertical spacing and the use of underlining. The set of control characters helped in preparation and reproduction of documents. In addition to the standard character set, a rich set of graphic symbols and a comprehensive set of control characters were supported in teletex. The use of such equipment considerably enhanced the character set available for document preparation.įeatures Character sets These units had storage for transmitting and receiving messages. Teletex envisaged direct communication between electronic typewriters, word processors and personal computers. The terminal-to-terminal communication service of telex would be turned into an office-to-office document transmission system by teletex. Teletex was designed as an upgrade to the conventional telex service. It was rapidly superseded by e-mail but the name Teletex lives on in several of the X.500 standard attributes used in Lightweight Directory Access Protocol. Teletex was ITU-T specification F.200 for a text and document communications service that could be provided over telephone lines. TTX11 terminal, in this case being relabeled IBM PS/2
0 Comments
Leave a Reply. |