Aucbvax.2603 fa.info-terms utzoo!decvax!ucbvax!info-terms Mon Aug 10 16:10:19 1981 [DREIFU: High Speed direct connect modems.] >From RAM@MIT-MC Mon Aug 10 15:45:18 1981 Date: 10 Aug 1981 (Monday) 1555-EDT Re: High Speed direct connect modems. Rockwell Intn'l is moving along very well in this field. They had at NCC'81 a demonstration of their 4800 and 9600 direct connect modems (sorry - no accoustic), running on unconditioned telephone lines. It is impressive. The limiting factor on telco lines is probably the relay and switchinng equipment, not the cable bandwidth. It would be interesting to know how far and through how much of the dial network these demos were. An unconditioned private linne might support 9600 baud at aprreciably greater distances than the ddd. An excellent work on the whole subject is "Technical Aspects of Data Communications", by John McNamara, published by Digital Press. His advice is basically don't count on an unconditioned line to remain satisfactory even if it starts out so, because the telco will have no obligation to keep it at any particular bandwidth. ----------------------------------------------------------------- gopher://quux.org/ conversion by John Goerzen of http://communication.ucsd.edu/A-News/ This Usenet Oldnews Archive article may be copied and distributed freely, provided: 1. There is no money collected for the text(s) of the articles. 2. The following notice remains appended to each copy: The Usenet Oldnews Archive: Compilation Copyright (C) 1981, 1996 Bruce Jones, Henry Spencer, David Wiseman.