Standards Understanding the Tools of the New Information Society
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NEW LIFE FOR OLD ÓSCILLOSCOPES 111 SEPTEMBER 1994 ElectronicsCombined with ElectrunicsR) NOW Modem Communications Standards Understanding the tools of the new information society Build This Phone Line Grabber to listen to your home from remote locations or to break into ongoing phone conversations Light-activated Sound Effects Generator Learn the GERNSBACK Morse Code Pu,_;41-kgri .5-DIGIT 9.5" 6'..; with the help of PC #PPi(PrIPP7797 50.7n7f7P P4P!- your $3.50 U.S. $3.95 CAN. APR 95 The Micro-Conductor 09:4 e teaches you how to play 11111111111111Amb keyboard instruments www.americanradiohistory.com Before you get turned on by the front of a meter, make sure there's something behind it. Fluke meters are designed for professionals who value function over frills. There's nothing superficial about the Fluke family of versatile digital multimeters. Pick one up and you feel that it's a substantial tool. Designed to fit the application and the way you work. 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Step 1 by step, you learn to create the kinds of full- City /State /Zip Accredited Member, National Home Study Council sois -0994 featured, powerful programs today's employers www.americanradiohistory.com Vol. 65 No. 9 CONTENDS SEPTEMBER 1 B 9 4 ON THE COVER "El 35 MODEM COMMUNICATIONS STANDARDS 44 TELEPHONE LINE GRABBER Use this There's no doubt that we're livnig in the Information Age, listening thanks in part to the proliferation of low -cost personal circuit to computers, which provide wide- spread, easy access via intercept phone telephone to on -line networks. Because the U.S. tele- conversations or monitor room phone system is activiities form a remote analog, a modem Modem Communications telephone.- Robert lannini is required to Standards Se.úl cum mmnms s.m0srds have mnde w io THE MICROCONDUCTOR translate the digi- comm. camwXCStlwn PessDl Mere box 46 M1 gales. standards. This microcontroller -based tal output of the music- training system allows computer into children to play and enjoy sounds that can music before they are old be sent over the enough for formal training. - James E. Tarchinski phone lines, and to convert those LIGHT-ACTIVATED audio signals back SOUND -EFFECTS GENERATORS into digital infor- You can generate strange mation on the sounds with this sound -effects other end. Since their introduction, modems have been generator that's based on a light- controlled, tone -burst continuously evolving as their speed and data -handling oscillator. - John Canivan capacity increase. It's been a challenge to create stan- dards quickly enough to keep up with the changes. MINUTE MARKER Modems operating under global standards are the inte- Generate variable- duration output pulses with selectable gral ingredient in worldwide comptuer communications. polarity and a wide range of This article provides an overview of modem technolo- time intervals, using this gy, specifications, terminology, and the latest standards. inexpensive tool. - Dev Palmer As a service to readers, ELECTRONICS NOW publishes available plans or information relating to newsworthy products, techniques and scientific and technological developments. Because of possible variances in the quality and condition of materials and workmanship used by readers, ELECTRONICS NOW disclaims any responsibility for the safe and proper functioning of reader -built projects based upon or from plans or information published in this magazine. Since some of the equipment and circuitry in ELECTRONICS NOW may relate to or be covered by U.S. patents, ELECTRONICS NOW disclaims any liability for the infringement of such patents by the making, using, or selling of any such equipment or circuitry, and suggests that anyone interested in such projects consult a patent attorney. ELECTRONICS NOW, (ISSN 1067 -9294) September 1994. Published monthly by Gernsback Publications, Inc., 500 -B Bi- County Boulevard, Farmingdale, NY 11735. Second -Class Postage paid at Farmingdale, NY and additional mailing offices. Canada Post IPM Agreement No. 334103, authorized at Mississauga, Canada. One-year subscription rate U.S.A. and possessions $19.97, Canada $27.79 (includes G.S.T. Canadian Goods and Services Tax, Registration No. O R125166280), all other countries $28.97. All subscription orders payable in U.S.A.