Path: utzoo!utgpu!watserv1!maytag!xenitec!zswamp!root
From: root@zswamp.fidonet.org (Geoffrey Welsh)
Newsgroups: comp.dcom.modems
Subject: review of Practical Peripherals 9600SA
Message-ID: <6058.27588AA8@zswamp.fidonet.org>
Date: Sat, 01 Dec 90 14:47:10 EST
Organization: Izot's Swamp BBS - Kitchener, Ontario

Kenneth J. Hendrickson (kjh@pollux.usc.edu ) wrote:

 >I found that _disallowing_ Data Compression yielded
 >higher data transfer rates!  This was true both for compressed files
 >(.ZIP) and for text files.  This was suprising, especially in the 
 >case of text files.

   In the case of .ZIP, .ZOO, .Z, LZH, etc. files, this should be no surprise 
to those who have been reading postings by myself and numerous others on the 
topic of MNP5 and precompressed data.

   On the other hand, I am puzzled by your results with text files. Were you 
using a non-streaming protocol (such as Kermit, XMODEM, etc.)? Higher levels of 
MNP can diminish interactive throughput; MNP5 should provide a significant 
boost to text file transfers using streaming protocols such as ZMODEM.

 >Then I tried to call the University's 2400 bps modems using the 
 >9600SA. I experienced lots of noise problems.

   I played with a USRobotics Courier HST (version 964) for nearly a year 
before concluding that the HST's 2400 stank. I do not have the same problems 
with my Evercom 940 (Everex internal 1/3-length 2400) or my Hayes Smartmodem 
2400.

 >I hope the Intel modem has better performance.

   We all hope, but it's been my experience that most of the low priced 9600 
bps modems have as their single goal 9600 bps performance; in many cases the 
2400 bps circuits used do not seem to have been adjusted for use with the 
(different) electrical characteristics of the 9600 bps circuits. This has the 
sad effect of doing real damage to the 9600's non-9600 bps performance.
 

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