|| The auto industry and the
computer industry have a lot in common. There's a lot of
hype, they both try to dazzle you with
"extras", and there are a lot of folks who tell
you that "cheaper" doesn't mean, well,
"cheaper." No surprise, then, when you see
advertisements for modems that look like something peeled
off the window of a car dealership. Buying a modem isn't
nearly as bad as replacing the old junker, though -- as
long as you stay focused on the basics.
There are three things to
worry about when you go looking for a modem: speed,
quality, and whether to get an internal or external unit.
For the vast majority of humanity, everything else in or
on the box is irrelevant.
Need for Speed
These days (late 1996), "speed" means at least
28.8kbps (28,800bps-- see the sidebar note). You can save
a few bucks -- not many -- by buying a 14.4kbps modem,
but it's not worth it. Sure, if you're only going to
spend a few hours per month doing a little email on the
local freenet, even an old 2400bps clunker will do the
trick but, if you plan on "surfing" the
Internet or playing around on one of the commercial
online services, a fast modem will pay for itself in time
saved, convenience and reduced online fees. "User
friendly" means "lots of graphics" and
everyone is trying to be user friendly anymore. And,
although a picture may be worth a thousand words, it also
takes a lot longer to download to your computer. (OK, OK,
the guy in the propeller beanie just asked about 33.6kbps
modems. Read on.)
Pay for It or Pay for It
All modems are not created equal. If
you live in a country with a solid telephone system, you
probably won't see much difference in performance between
a cheapo and a more expensive modem but you will very
likely encounter a difference in reliability. Cheap
modems don't last as long. I've seen some real dogs that
died in less than a year. There's a pretty tight
relationship between price and quality. And quality
doesn't cost that much more -- less than $50 in most
cases. I won't cast aspersions on any specific
manufacturer but, if you see two 28.8kbps modems on the
shelf, one produced by Xyzzy Corp. for $99.95 and the
other made by, say, Practical Peripherals (PPI) for $20
or $30 more, buy the PPI unit.
While you are wandering around the store,
you'll also notice that modems come in two basic flavors:
internal and external. (Sounds vaguely obscene, doesn't
it?) As you might expect, an internal modem is installed
inside your computer whereas an external modem is cabled
to an extra serial port and sits next to the machine in
some convenient spot.
Most folks buy internal
modems. Physical installation is a mild hassle, but they
typically cost $20 to $50 less than external modems, you
don't have to worry about serial port performance issues
and you don't have an extra piece of gear cluttering up
your desk top.
On the other hand, external
modems have two big advantages over internal devices: The
display panel lets you see what's going on and, if a
dial-up session gets really snarled up, you can turn off
the modem instead of rebooting the whole computer.
However, you must have a spare high-performance serial
port (see sidebar on UARTs). If your serial port is not
up to snuff, you can't run an external modem reliably at
speeds much above 9600bps. If you don't know what type of
serial port your computer has, find out. A lot
of people have gotten burned by this one. MS-DOS and
Windows users can boot to MS-DOS (do not use a DOS
prompt from within Windows) and run a program called MSD.
If MSD says you have "16550A" serial ports,
you're OK. If not, either buy a high-performance serial
card (another $30) or get an internal modem. And you need
to buy a shielded serial cable, too, by the way --
a $5 to $10 investment.
All that being said, I like
external modems. I spend a lot of time online and like
being able to see what's happening on the phone line.
Internal modems give me a pain in the nether regions but,
then, I'm not exactly a "normal" user, either.
It's your call (pun intended).
A Movable Beast
What about modems for portable computers?
Well, PCMCIA card modems are subject to the same speed
and quality issues as conventional modems. There are only
two significant differences: They cost more and they are
all, in effect, "internal."
A Word or Two About
Fax modems - These days, saying
"fax modem" is like saying "new car with
air bags." It would be most unusual to find a decent
high-speed modem without fax capability.
Software - Just about every modem is sold with a
generous handful of software of problematic utility. If
you can't decide between two different brands and one
includes a software package you like, buy that one. The
only important question here is whether or not the modem
is already supported by your operating system. If not,
then make sure the manufacturer supplies the necessary
drivers and utilities.
| "Modem" stands for MOdulator
/ DEModulator. It's a hunk of circuitry that takes
digital data from a computer and converts
(modulates) it into a signal that can be sent
across a telephone line to a modem hooked to a
computer somewhere else. It also converts
(demodulates) the signal from the remote
computer's modem into data that can be understood
by your machine. In other words, it lets two
computers talk to each other over a phone line
that was originally designed for voice.
You'll often see modem
speeds specified in "baud" or
all practical purposes these days, the two terms
are equivalent -- 28,800baud is the same as
28,800bps. "Bps" stands for "bits
per second," it's the number of bits a modem
can send or receive in one second. Wouldn't
characters (or bytes) per second make more sense?
Sure, but a bigger number looks better on the
outside of the box. To get characters per second,
just divide the modem speed (also called the
"baud rate") by 10. So, 28,800bps is
2880 characters per second -- still pretty darn
fast when you think about it.
Curiously, the term
"bps" is seldom used in conversation --
probably because it's easier to say
"bawd" than "bee pee ess."
A UART is a chip that
handles the serial port on a computer. (If you must know, UART stands for
Universal Asynchronous Receiver - Transmitter.)
Most modern IBM-style PCs have two serial ports,
one for the mouse and the other for an additional
"serial device" such as an external
modem. Up-to-date machines have "high
performance" serial ports operated by
circuitry that looks like an NS16550A UART (also
known simply as a "16550A" -- the
"A" is important). If you don't have a
16550A-style serial port, you can't handle a
high-speed external modem properly.
If you have poor quality
telephone lines, you need a high quality external
modem. As a general
rule, a top of the line modem from a very
reputable manufacturer will do a better job of
handling line problems than an
"economy" modem. It's also a very good
idea to get an external modem. It will give you
more information on line conditions than an
internal modem and do a better job of isolating
your computer from line voltage fluctuations. A
"top drawer" external modem from an
outfit like Practical Peripherals, Motorola or US
Robotics can be an expensive proposition, but a
cheap modem is likely to perform poorly and have
a short lifespan.
There are many different
ways modems can talk to each other. The reason this doesn't result in a
sort of electronic Tower of Babel is because the
various manufacturers adhere to a set of
international standards or protocols.
These are the "V numbers" you'll often
see displayed prominently in modem advertising.
For instance, V.34 is the protocol for
communicating at 28.8Kbps. So, if a modem
"does" V.34, this just means it can
talk to another modem at 28.8Kbps. Other "V
numbers" you are likely to see are V.34
annex 12 (33.6Kbps) and V.32
(14.4Kbps). There are at least seven more of
these "speed" protocols, not to mention
a whole grab-bag of standards for data
compression, error correction and fax
transmission, but they usually only show up in
the fine print.
|| 33.6kbps modems - The
extra speed is nice, but not a critical issue. The
33.6kbps protocol (known as V.34 annex 12, if you really
care -- see the sidebar on protocols) has recently become
an official standard. If your local service provider has
dial-in lines at this speed (mine does) and if your phone
lines are clean enough to handle it, it's nice to have.
Over the next year I imagine that all of the modem
manufacturers will either upgrade their existing 28.8kbps
models to 33.6kbps or bring out "new" models,
dropping the price on the old ones.
Better yet, many of the
newer 28.8kbps modems are field upgradeable to the
higher speed -- i.e., they just need to be reprogrammed.
Typically, the upgrade package is a free download from
the manufacturer's web site or bulletin board system. (Or
they'll send it to you on diskette for a nominal fee.)
The package includes an application that reprograms your
modem to handle 33.6kbps and some updated files for your
56kbps modems - [Updated 10 Mar 97]
Speaking of upgrades, 56kbps modems are looming on the
horizon. Expect to start seeing this capability in early
1997. Remember, though, that these higher speeds are
somewhat academic to a lot of folks. Without a first-rate
modem and a pristine telephone connection, you'll be
lucky to do any better than 28.8kbps. Furthermore, your
local telephone office must use digital switching.
If they are still using the old electro-mechanical
switches (not uncommon in rural areas), you can forget
Here's another little
detail: These 56kbps modems aren't really 56kbps modems.
Right now, it looks like we'll get around 53kbps incoming
and 33.6kbps outgoing. This is still a pretty good deal
-- most people spend a lot more time doing things like
viewing web pages than uploading files -- but the
"56k" designation is still a little deceptive.
Mind you, the engineering types originally thought that
they would get 56kbps, so don't start sending
nasty-grams to the manufacturers.
Speaking of manufacturers,
there are presently two competing "56k"
standards. US Robotics and their allies are pushing one
approach while another group is betting on the Rockwell
chipset. So, be warned. "Early adopters"
(myself, for instance) are only going to see
"56k" speeds if they connect to a modem that
uses the same 56k protocol. If you don't want to put up
with this hassle, wait until the standards shake out.
Plug and play - PnP is a nice feature;
potentially, it lets you avoid some configuration
hassles. But don't let it divert you from the basics. A
good modem without PnP is a better buy than a cheap one
with PnP. Automatic device configuration is definitely
the wave of the future, but it's not a tsunami
Voice mail - Private voice mail capability could
be rather handy, especially if you are running a small
business. There are a few significant caveats
here, though: You need the appropriate type of
distinctive ringing to discriminate between data, fax and
voice calls, you probably need a good chunk of free hard
drive space to store incoming messages, you must have
sufficient computer horsepower, and you have to leave
your computer on all the time. There is also a fair bit
of open territory in the area of software support. How
well, for example, does the voice mail software
coordinate with your existing dial-out applications? It
will cost you an extra $30 to $60 to find out. Voice
modem standards have not shaken out yet. If you
just want to climb on the net and maybe do some faxing,
save the extra money and send it to me, instead.
So, here's the basic modem mantra:
"speed, quality, inside or outside." Chant this
under your breath as you browse the latest catalog or
wander through Fast Freddy's Computer Barn and you won't
go too far wrong. I wish I had something like that for
There are a lot of modem manufacturers and vendors
out there. I've found that the best place to start
looking for them is the list of links maintained by
Yahoo - Business and