Winmodems are not modems

The purpose of this page is to identify consumer-grade modems systematically and to note compatibility with Linux as reported by you, the users.

Special thanks to the following translators:

  • (Japanese), (Italian), (Portuguese), (Spanish), (Turkish), (Greek), (Serbian), (German), and (Romanian).
The most current English language version is located here:

IntroductionNewsFAQModem DatabaseChipset DatabaseRough GuideLinks


So-called Winmodems, host-based, HCF-, HSP-, HSF-, controllerless, host-controlled, and soft modems require vendor-supplied software to do the work of proper hardware modems. The sale of these devices for x86-based PCs is becoming increasingly popular among retailers and OEMs because of their lower cost.

Since 1998, my opinion on these devices has been tempered by changes in:

  • how the chip-makers and modem-makers have acknowledged the growing base of Linux users,
  • the installed base of PCs that are capable of using a host-based modem without significant impact on the CPU, and
  • the emergence of PC motherboards with AC'97 capability.

This section used to say:

However, Winmodems are only appropriate for use with Microsoft Windows on a fast Pentium.
I'm not sure this blanket statement is still true. As evidenced by the big list, there are many GNU/Linux users using their "linmodems" with varying degrees of success. On the other hand, this does not help all the *BSD users, the x86 Solaris users, and others who would also benefit from non-proprietary software drivers.

A chart summarizing the hardware differences between traditional modems, controllerless and software modems can be found here or, for a longer explanation, here or here.

The developers at have coined the term Linmodem to describe a winmodem that can be used with Linux with a commercial or open-source driver.

It has been pointed out to me that the name "Winmodem" is/was a registered trademark of U.S. Robotics (or 3Com while they were merged). I'm sure that they are proud of this fact ;) In any case, when I refer to Winmodems, please read it as "Winmodems(tm), host-based modems, HCF-modems, HSP-modems, and all similar modem-like hardware."


What's new

Added a link to Dell's Broadcom BCM421x driver. Thanks to John Martiney for locating this driver!

The Conexant HCF driver now supports older Rockwell (127A) PCI chipsets as well as 14F1:181x Combo Lan/Modem cards



Winmodem Mini-FAQ

1. If Winmodems are not really modems, why do manufacturers make them?
It all comes down to cost. First, a winmodem lacks parts found in regular modems-- these parts are "emulated" by software running on your CPU. This lowers the unit cost to manufacture them. Second, most consumers using Microsoft Windows will never realize that their "56K Modem" is actually a winmodem, so the OEMs are happy.

2. Oops, I bought a Winmodem. Will it work with Linux?
Not without some effort. A Winmodem requires software to emulate the hardware missing from the modem card. For some winmodems, such as the 3Com/US Robotics Winmodems, this software is only available for Microsoft Windows. For most others, there are groups adapting proprietary drivers to function as "Linmodem" drivers.

3. This all sounds way over my head. Just tell me where to get the .rpm.
Sorry, the whole idea of using binary drivers in a Free operating system is an ugly hack. Consider this an opportunity to learn more about your computer :) Honestly, you must know which of several types of winmodem you have in order to pick the right driver.

Please remember: if you have a choice, a hardware modem is always the best choice for Linux users. If you have a laptop with a built-in winmodem, though, you'll need a "linmodem" driver.

4. Are there any external Winmodems? Am I always safe getting an external modem?
Standard serial port (RS-232) external modems are usually fine, no matter what make or model.
Many USB external modems are winmodems and should be avoided. If you are interested in the status of USB support in Linux, please follow the link to the Linux-USB uusbd development page.

5. How about PCI modems? Are all PCI modems winmodems?
No, there are at least three types of controller-based PCI modems. They are somewhat more difficult to set up than a jumpered ISA modem or an external serial port modem. Linux 2.4 will probably include automagic setup of PCI hardware modems.
If you are curious, these modems are:

Lucent Venus chipset:
   Multitech MT5634ZPX-PCI,
   Zoom 2920 (Digitan DS550-558),
   Actiontec PCI56012 (IBM 33L4618 or GVC MD0223)

USR/TI Kermit chipset:
   the 3Com/USR 3CP5610 family, which includes models 5613, 5609, and OEM models 2976, 2977, and 3258

TOPIC TP560i chipset:
   Well Communications FM-56PCI-TP (GVC MD0321), and
   Archtek Smartlink 5634PCV.

Conexant RC56D-PCI chipset:
   none observed yet

6. Are there any Linmodem drivers for kernel 2.0.x? 2.4.x?
A few have been ported to 2.4.x. But there are none for 2.0.x. Now you can see why closed source drivers are such a bad idea.

7. My modem is not a winmodem but I'm still having problems getting Linux to "see" it or the modem is always "busy." Why?
The most common reasons are:
   Unconfigured ISA Plug-and-Play modem
   "User-friendly" dialing programs which have their own problems. Test your modem with minicom instead.

The Modem-HOWTO has an up-to-date troubleshooting section.


Linux/Modem Compatibility Knowledge Base

Usual disclaimers apply. This list is provided only for your convenience and should not be considered an endorsement blah blah blah ;-) Experienced Linux users-- I need your help to mark more modems OK

Sample FCC label

If you're looking for a particular modem, be sure to use your browser's "Find in Page" command. It may not be where you think it should be!

WM = Winmodem, only proven to work with Windows software so far
LM = Winmodem, may work with vendor-supplied Linux ("Linmodem") driver
RP = Rockwell RPI chipset, requires DOS or Windows DSP software, may work with error-correction disabled
OK = Real modem, reported to work with Linux
Red = Windows-only chipset
Orange = Rockwell RPI chipset
Yellow = Winmodem chipset with "Linmodem" drivers
Bucks = Winmodem chipset with Linux driver that must be purchased
Green = Full hardware chipset

View the PCI list
View the ISA list
View the RS232 External list
View the USB list
View the PCMCIA list
Recent Changes
LM BDNM507B1001 HSFi Sterling Communications S20 Model V.92, Conexant CX11252-11 chipset - - PCI Johnny Lee
LM 5OITAI-33986-M5-E MonoPak HCF Model PT-3517, Conexant R6785-11 (Monopak HCF) chipset (PCI\VEN_14F1&DEV_1035&SUBSYS_103514F1&REV_08)
- - PCI Graeme Moss
WM 6CTTAI-34146-M5-E LU97 Ambit 56K/14.4 Fax for PC, Sony Vaio Picturebook C1MHP - - MDC Florian Lohoff
OK 2U6USA-24769-M5-E   CreditCard Modem CM-56G(xx) GlobalACCESS - - PCMCIA Dietrich Radel
OK GDE0193
  Cardinal  MVP144IV2 14.4 Internal Fax Modem w/Voicemail, Model 020-0469, Windows s/w for PnP, (PNPID CRD0005), ATI3 reports RPI, but has Hardware ECC with RC144ACF Yes No ISA Thomas Jones-Low
LM LNQTAI-34542-M5-E PCT1789 Actiontec HSP56 - No PCI Justin Keyes
LM - MonoPak HCF Sweex 56K PCI Hardware, Rockwell RH56D/SP-PCI R6795-11 (Monopak HCF) chipset (PCI\VEN_14F1&DEV_1085&SUBSYS_108514F1) Yes No PCI Steven Hendriks
LM H8NTAI-35629-M5-E SmartRISER56 Askey 1456VQL12(INT), 1456VQL4(INT) internal mobile daughter card 56K/14.4K d/f modem (Toshiba Satellite 1415-S173), Smartlink SmartRISER56 chipset - No MDC Moss
? BDNUSA-43505-M5-E SmartHCF-USB Zoom/Modem Mini USB Model 2990/3090, Zoom XXXX-0370-YY, Conexant SmartHCF-USB chipset (USB\VID_0572&PID_1253) - - USB Eddie Kuns
OK - SC56D TeleWell TW-5614UL+USB, V.90/V.92 external modem, Conexant SC56D chipset - - EXT/USB Heikki Keränen

Rough Guide

These are handy tip sheets for shopping at chain stores that will fit on one piece of letter-sized paper when printed. Usual disclaimers apply.

Links to other modem information

Reference notes/esoterica for this page

Modems in general

Helpful HOWTOs and tutorials

Laptop modems and Linux

Specialized Linux software

  • spk, a GPLed voice mail system for Linux
  • xsmp, an X interface for Sportster Message Plus modems
  • mepl, software to control the self-employed mode on 3Com/USR message modems
  • TkUSR, a small Tcl/Tk program for USR/3Com message modems
  • Olix, une application qui permettra la gestion du modem Olitec (Self Memory 2000, 56, et compatible).
  • PMFax, fax/voice software for several OSes.

Choosing or buying a modem

Put away that hammer: the gurus are trying to turn winmodems into "linmodems."

Manufacturers' Linux pages [The good guys]

Manufacturers Hall of Shame

Supported hardware lists for specific commercial Linux distributions -- included for completeness, but not recommended

Other Operating Systems

ISDN, cable modems, other stuff like that

"Leisure and curiosity might soon make great advances in useful knowledge, 
were they not diverted by minute emulation and laborious trifles."
--Samuel Johnson, 1751
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