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Modem Test (1/2)


CR 9600

The USRobotics Courier HST modem is the new choice for today's sophisticated data communicators who demand the highest standards of quality and reliability from their equipment. The $995.00 Courier HST offers a combination of price, performance, quality, reliability, and SPEED that no other modem can match. The Courier HST is a fully-featured modem that with special features that professional users will find ingenious and indispensable. Standard features found on the Courier HST include:

* 9600 BPS -- ERROR-FREE: The Courier HST offers error-free communication at data rates up to 9600 bps. It also automatically falls back to 2400, 1200, and 300 bps to guarantee compatibility with virtually any other medium-or low-speed modem in the field.

* TRELLIS-CODED MODULATION: At 9600 bps, the Courier HST employs Trellis-Coded Modulation a convolutional coding technique that makes data transmission less vulnerable to errors caused by phone network impairments. It can tolerate twice the telephone channel noise power as conventional modulation, so there are fewer error - control retransmissions. Trellis-coded modulation is also less susceptible to impulse type noise.

* ASYMMETRIC FREQUENCY DIVISION: At top speed, data flows in one direction at 9600 bps and at 300 bps in the other. The modems automatically switch the high - speed channel on demand, i.e., depending on which transmitter has the most data to transmit. In practice, the modems seldom need to reverse channels, since the asymmetric design reflects typical communication sessions brief messages typed at one end of the link, files sent from the other. The asymmetrical approach provides the most efficient and economical strategy for using ordinary phone channels at high speeds.

* ENHANCED ERROR CONTROL: The HST error control protocol uses sophisticated error detection methods to ensure data integrity. In addition, design efficiencies have reduced the overhead (extra control information) experienced with lower - speed error control protocols. In addition, the protocol doesn't slow down on long-distance connections. The result is accuracy, greater speed and higher throughput -- approximately 11,000 bps.

* SHORTER RESPONSE TIME: Most 9600 bps modems are most efficient for file transfers. You will find that the Courier HST offers faster response times for interactive sessions as well.

* THE COURIER PRODUCT FAMILY: In addition to the Courier HST's new features, the modem incorporates the same popular capabilities of other products in the Courier line:

* MNP ERROR CONTROL: At 2400 and 1200 bps, the Courier HST implements MNP, a sophisticated error and data flow control protocol that ensures error-free data transfer. The protocol is especially useful when files containing numeric data are being transferred, or computer programs, in which a single incorrect character can cause failure.

* INACTIVITY TIMER: You can set the modem to automatically hang up after a specified number of minutes if there is no activity on the phone line.


This article originally appeared in the Amiga diskmagazine "Zine #5" by Brainstorm 1990.

Some content may refer to activities that are illegal in some countries. BitFellas does not support such activity.
Addresses and other contact information were only valid when this magazine was originally published, in june of 1990.

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