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Article: A surfeit of standards. (modem standards) (Computer Shopper's Guide: Modems) (buyers guide)
- Article from:
- Computer Shopper
- Article date:
- October 1, 1991
- Author:
CopyrightCOPYRIGHT 1991 SX2 Media Labs LLC. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
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Standards determine whether a given modem can successfully connect with any other modem in the world.
Bell 103 uses a kind of modulation called Frequency Shift Keying, or FSK, in which a specific tone frequency signifies a digital one and another a digital zero. Each change in the modem's signal thus carries one bit of digital information. Consequently, the Bell 103 standard is the only one in which the baud rate (the rate at which signal changes) is equal to the data rate of 300 bps.
Bell 212A is the next logical step and the second modem standard to find wide application in the United States. It achieves a data-transfer rate of 1,200 bps by using ...