Zoom FaxModem V.34X

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                     Review: Zoom FaxModem V.34X
  By Jeremy Nixon                                    jeremyn@injersey.com
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How do you choose a modem?  How do you even tell the difference?

There I stood, in Computer City, staring at a wall of modems.  I wanted a
28.8k, V.34, external modem.  At least half the options qualified, with
prices ranging from about US$150 to $300.  Anything over $200 was
immediately ruled out.

The "helpful" sales associate informed me, quite seriously, that it is
"impossible" to use a Mac modem on a PC, or vice versa, regardless of what
sort of cable you have.  "They just don't work that way--they have
completely different programming."

I thanked BrainBoy for his help and sent him on his way, daring not mention
that I have neither a PC nor a Mac.  The sales staff, apparently, was not
going to be of much help.

After much box-reading and option-weighing, my choice was the Zoom FaxModem
V.34X.  I have to admit the reason was a combination of price and nice
packaging.  I paid US$169, on sale; the price was listed (in Computer City)
at $199.

The modem doesn't come with a cable, so I had to get a 25-to-25 modem
cable, too.

SPECIFICATIONS

As you probably know, if you read the specs on any six V.34 modems, you
will begin to have a sense of deja vu.  The Zoom supports all the stuff
you'd expect it to support: speeds up to 28,800bps.  V.34, V.FC, V.32bis,
V.32, V.22bis, Bell 212A, V.22...well, you get the point.  Fax (Group 3,
Class 1 and 2) up to 14,400bps with V.33, V.17, and on and on.  Flow
control with RTS/CTS, XON/XOFF, etc.  DTE speeds up to 115,200bps.  Auto
speed sensing.  V.42bis and MNP5 compression.  MNP10EC error correction.  
Non-volatile memory.

About the only thing it doesn't have is built-in Caller ID.  You can get an
upgrade kit for that, though I don't know what it entails.

You also get several blank disks--er, I mean, free offers from online
services, including AOL (of course), Compuserve, and GNN.  And some DOS
software, in case you've got a PC sitting next to your Amiga.

INSTALLATION

Quite easy.  Plug the modem cable into the modem, plug the other end into
your serial port, plug the power cable into the modem, plug the other end
into an outlet, and you're off.

DOCUMENTATION

The Zoom comes with a nice manual of 56 pages.  Parts of it deal with
installing the internal version into a PC and thus can be skipped.  You can
also be walked through the procedure of choosing an init string, in case
you're not familiar with AT commands.

The ten-page troubleshooting section seems comprehensive, though I haven't
had to put it to the test.

You also get a nice chart of AT commands, including the modem's default
settings, which comes in handy if you already know how to use them and just
need to look one up.  And beginners will welcome the six-page glossary of
terms.

One interesting fact about the manual: nowhere does it specify what kind of
modem it's talking about.  The word "Zoom" appears only in a line-drawing
of the modem.

GETING UP AND RUNNING

I don't know if this is unusual, but the Zoom worked perfectly the first
time I tried it.  I looked through the manual and assembled an appropriate
init string for Term (AT&F&C1&D2W1), set my serial port speed for 38400
(more on this later), dialed, and there was my UNIX account.

For PPP, I used the same init string, changing the &D2 to &D0, which
assumes the DTR (Data Terminal Ready) is on.  That worked just fine, too.

The only problem I encountered was when using PPP, and I've seen several
questions relating to this on the newsgroups.  When you first power up the
modem, several lights come on, one of which is CD, for carrier detect.  I
believe this to be a byproduct of the default &D0 setting (which can be
changed).  When you attempt to start the PPP device, it dumps out with an
error.

I found that starting Term, and allowing it to send its init string to the
modem (with the &D2), the CD light would turn off, and I could then quit
the program and use PPP.  A better workaround would be to change the
modem's default settings, but I use my UNIX shell account about 95% of the
time anyway, so I didn't bother.  The point is, if PPP gives you an error,
look for that CD light.  This isn't a problem specific to the Zoom, of
course.

PERFORMANCE

I'm pretty happy with the Zoom's performance.  But, as with any modem, you
have to set your DTE (computer-to-modem) speed on your serial port to a
speed your hardware can handle in order to obtain the best results.

On my machine, the best speed I can get is 38400bps.  If I try to drive the
modem any faster, the transfer rates drop like a brick, because the Amiga's
serial hardware just can't handle it.  I suggest you try a variety of
speeds to see what your machine can do; I've heard from several people who
can use 57400 just fine, and one who can even use 115200, though on an
Amiga I'd have to see that to believe it.

Basically all I use the modem for is to call my Internet provider, and I
almost always get a full 28800bps carrier with the Zoom.  I should note,
however, that I have very good telephone lines in my area.  I once also
used it to call across the country (California from New Jersey) and I got
28800 then, too.  The slowest speed at which the Zoom has ever connected is
26400bps.

Driving my serial port at 38400, my Zmodem downloads and uploads range from
2900-3700 characters per second, using the "sz" and "rz" UNIX programs in
my shell account, and xprzmodem.library in Term.  I don't know what
accounts for the differences in speed--it could just be usage load at my
ISP.  The absolute fastest download speed I've seen on a file of reasonable
size was about 3950 cps.

Bumping my serial port speed to 57400 makes these numbers drop to about
1400-1500 cps.  115200 is almost unusable.  However, this is not at all the
fault of the Zoom, but rather the outdated serial hardware in the Amiga.

The Zoom also supports faxing.  I don't have fax software, or access to a
fax machine to test it with, so I can't comment on it.

THE BOTTOM LINE

I am very happy with the Zoom.  I was able to plug it in and forget it
(until I wrote this review, at least) and it gives me great performance for
a competitive price.  So go ahead and buy one.


Zoom Telephonics, Inc.
207 South Street
Boston, MA 02111 (USA)
(617) 423-1076
http://www.zoomtel.com

TEST SYSTEM

Amiga 500 (rev. 8a PCB)
OS 3.1 & ECS
CSA Derringer 030/882
2 megs chip + 16 megs fast RAM
AdIDE controller w/100 meg HD

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This article is Copyright 1996 by Jeremy Nixon, All Rights Reserved.
It may not be published anywhere except Amiga Report without specific prior
permission from the author.

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