Copyright (c) 1998 by Timothy C. Barmann. This article is intended for personal viewing only and may not be re-distributed in any form. Please e-mail link requests.
July 5, 1998
shortcomings of `Winmodems'
By Timothy C. Barmann
If you've been modem shopping lately, chances are you probably didn't notice that there are two distinctly different kinds of modems lining computer-store shelves these days.
There are the traditional modems, of course, that plug into just about any computer -- Macintosh, Windows, DOS, and so on.
But right next to these modems are another similar-looking type often referred to as ``Winmodems.''
The reason the two types of modems don't appear very different is because modem manufacturers are not going out of their way to tell you the difference.
Winmodems have been around for several years and they are more popular today than ever before because they can cost $20 to $50 less than their traditional counterparts.
But these modems are fundamentally different than standard modems. In simplest terms, Winmodems are like regular modems that have been lobotomized: some of their brainpower has been removed. To save money, modem manufacturers such as U.S. Robotics and Diamond Multimedia have designed modems that have fewer chips and rely on your computer's central brain, the CPU, to do much of the work.
Windows-only modems require the CPU to handle things such as processing the signal as it arrives at your PC from the telephone line, correcting wayward bits, and compressing and decompressing data.
That leads us to the first drawback. Since the modem is relying on the CPU to do some of its work, it keeps the processor from giving its full attention to the other programs you are running on your PC.
That, in turn, can affect the performance of your entire system, depending on how fast and what type of processor you have and what kind of modem you buy. A faster processor, say a Pentium 200, may be fast enough that you won't notice any performance drag. Processors that use MMX technology are especially designed to handle some of the work Winmodem's give them. But computers that use older, slower CPUs, such as a 486/66 Mhz processor, may slow to a crawl when using them with a Winmodem.
Some Winmodems may demand more of the processor than others. A frequently-asked-questions document by one modem maker, Royal PC, says that its Windows-only modem takes up to 50 percent of the CPU's cycles on computers that use the Pentium 100 Mhz CPU, when used to connect to the Internet. That means that while your browser is trying to draw a Web page on your screen, your CPU is split between trying to do that and trying to process the data streaming in from your phone line.
By contrast, a traditional modem operates independently of your processor, so your PC can devote most of its attention to displaying the Web page.
Jim Thomsen, a product manager for 3Com, the maker of the popular U.S. Robotics modems, said most computer users will not notice their machines slowing down with Winmodems. He said that a U.S. Robotics Winmodem running on a Pentium 200 draws less than 5 percent of the CPU's processing power. However, he said he couldn't provide percentages for slower PCs.
The other major drawback with these modems has to do with why they are called Winmodems: they work only with Microsoft Windows software. That means they simply won't work with older DOS-based communications programs, such as the old standby, Procomm Plus, or with multiplayer DOS-based games that let you battle it out against friends over your telephone line.
This also could be a major drawback for those who need to use DOS programs to communicate via modem, such as companies that use the older software to send files back and forth to employees, or small businesses that use DOS-based software to process credit-card transactions.
It also means the modems probably won't run on Macintosh computers, or on IBM-compatible PCs running a different operating system such as OS/2 or Linux.
However, Windows-only modems do have some advantages. For example, they are usually easy to install. Because of their hardware differences, they don't take up a communications port as traditional modems do. That lessens the chance there will be conflict with another piece of equipment.
And upgrading the modems is easy. Upgrades usually come with an installation program that copies certain files to a particular directory.
But modem manufacturers often talk about Winmodems in glowing terms and tend to leave out the shortcomings.
3Com makes no mention of either of these shortcomings on its main Web page for its Winmodem product. You won't find out about its inability to use DOS programs unless you happen to see a page of installation tips for Windows 95 users.
There, it does say: ``The Winmodem is strictly designed to work on IBM PC based machines, running Windows 3.1 and Windows 95. The modem will not work under DOS, a DOS Window, or any other type of machine.''
I couldn't find any mention of the DOS limitation on Diamond Multimedia's site. The San Jose, Calif., company recently introduced its SupraMax line, which will not run DOS software. Even on the technical details Web page, it says only that an IBM-compatible computer (Pentium 133 or higher) and Microsoft Windows 95 are required. To most people, that's not clear that it won't work on DOS programs since most new hardware is usually compatible with older software.
There is a work-around to the DOS compatibility problem. Pacific CommWare Inc. (http://www.turbocom.com/) of Ashland, Ore., makes a product called TurboCom ViP, a software program that lets a Winmodem modem run DOS applications. 3Com ships this software with its Winmodems that come installed on new computers, such as those sold by Dell and Gateway, according to Thomsen of 3Com.
But if you buy the modem as an upgrade off the store shelf, you'll have to pay $30 for it. If you need to use DOS-based communications programs, you would be better off using the extra $30 to buy a standard modem in the first place.
Winmodems may be perfectly fine for most people. If you've got a faster machine, or have no need to use DOS-based communications programs, or if you never plan on switching from Windows to another operating system, you should have no trouble.
They can be inexpensive, too. Diamond's SupraMax 56K modem is only $49, after a $20 rebate.
But modem makers should do a better job differentiating Windows-only modems from traditional modems and they should be more up-front about their products limitations.
Each box should clearly state something to the effect of: ``Will not work with DOS communications programs,'' instead of the ambiguous ``Requires Microsoft Windows.''
Thomsen said 3Com is considering going beyond that by providing the TurboCom software with Winmodems bought by end users.
Some computer manufacturers make it sound like some kind of bonus that the modem uses your CPU. Diamond says its SupraMax modem ``takes advantage of your PC's processing power.''
Instead, Diamond and other manufacturers should put a chart on each package showing what percentage of computing power the modem steals from various CPUs, just like car makers must tell how much gas mileage a new car gets.
That way you'll know not only the price you'll pay in monetary terms, but the price you'll pay in lost computing power as well.
Timothy C. Barmann is a Journal-Bulletin staff writer. His column runs every other Sunday on the Computers and Technology page. Send him comments via e-mail at firstname.lastname@example.org or U.S. mail, c/o the Journal-Bulletin, 75 Fountain St., Providence, R.I. 02902.
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