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PCTel Chipsets Updated 14-Jul-05

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May 2003: PCTel sells softmodem business to Conexant. Drivers and support for PCTel modems are no longer available from the PCTel site. (Generic drivers are now available from Conexant - see link below.) PCTel itself remains a separate company now focused on wireless-related product.

PCTel made only HSP (host signal processor - softmodem) modem chipsets - purchased by 3rd-party manufacturers that make the actual modems. A number of PC manufacturers bundle a modem with a PCTel chipset in their system package. I think it's unlikely that Conexant will continue to develop 2 lines of chipsets: while there's still quite a supply of PCTel modem product, this may become an "orphaned" product. Conexant already made a full line of hardware and software modem chipsets, and acquired license to PCTel modem patents for Conexant products. (See Conexant Press Release.)

Because PCTel modems are all softmodems, the only difference between V.90 and V.92 modems is the driver. PCTel's V.92 driver includes 'built-in-the-driver' call-waiting/modem-on-hold - this supports incoming call-waiting only, it will not allow modem-on-hold to place an outgoing call.

As with any 56k modem, assuming you have a 56k-compatible line, the driver (or firmware) for your modem is the single most important factor in the quality of your connection. While these modems will get 56k connects, there are more interoperability problems with these modems - and you should check to see if a new driver is available for your modem.

Drivers for PCTel modems may be found from the various OEM sites, and, from Conexant.

COMPAQ - has released driver version 8.0K-C for WindowsMe only and the "Presario PC-TEL Platinum Connect V.90" modem as SoftPaq #16792: download   readme.  [Compaq ServicePaq's 15329, 15617 and 15697 are older WindowsMe drivers for the PCTel.] Windows-2000: Compaq ServicePaq 16794 provides  v 8.0 Win2k driver; Compaq ServicePaq 16793 provides Win95/98/Me v8.0 driver. Note that Compaq softpaqs may work only if you keep the Compaq pre-loaded Windows and drivers: if you use a retail, or upgrade version of Windows, the softpaq may fail.

PCTel chipsets 288(ISA), 388(PCI) & 789 (PCI) support V.90 and K56Flex under Windows and Linux. The driver is CPU-dependent (different drivers for Intel Pentium, MMX's, and Cyrix). These are no longer made.

PCTel's 1789(PCI) chipset supports V.92 and lower protocols.

Vendors that make modems with this chipset include:

Actiontec  (PCLite)
Askey (V1456VQH-P2)
Aztech (MSP 5800)
Best Data (AS56FW; 56HP92-PCT)
CIS/Wisecom (WS-5614PMEA, PMEB, HMVC)
E-Tech (PCI56PVP[+] HSP)
Harmony (HM18021-1 Data/Fax/Voice)
J-Mark (A1456VQH-P2)
Jaton (WinCruise V.90 PCI & SL HSP)
Lectron (Pragmatic I56PSP-F0, F1, F2 -  Data/Fax/Voice/TAM)
Paradise (WaveCom 56k PCI HSP)
Taicom (MP56PVS-Soft)
Wellmodem (Origo FM-56PCI-PT 56K Data/Fax/Voice)
Zoltrix (8FM-56KIPCTPCI 'Phantom')

PCTel AC97 AMR Chipset - Software hosted modem for use in systems that have Audio Modem Riser (AMR) 2.1-compatible slot on motherboard.  This product is discontinued and has been replaced with the PCT2303 AC-Link Chipset which supports V.92. Modems based upon these chipsets can be made for notebook computers as well as other non-PCI form factors. (AMR, Mini PCI, Daughter Card, etc.) The PCT2303 uses 2 small chips to provide a programmable interface to the telephone line, and does not use relays, transformers, or opto-isolator which makes this a very low cost modem. Vendors include:

ECS Elite Group of Taiwan - updated driver including WinXP; Ver 2.30 build 2029.41
Hightech Information Systems [HIS] - (PCTel-AMR: has no drivers for this modem - has picture & specs.)
Pine Group - (Pine/Comstar FM-3811-2 AMR V.90 (Pine drivers: For Win9x/NT/2k  WinMe Driver from
PC Wave - has drivers for PCTel AMR (stupid site design requires Flash for navigation and prevents placing link to other than front page.)

Additional links that may help:
PCTel Unofficial Websites
Hi-Val Modem Driver page - This company has made modems with Lucent, Rockwell, PCTel, ESS, and TI chipsets and has drivers (usually without version #) for them all.
Freeware fpr  PC-Tel HSP Configurator (allows country and other configuration setup).

Most of the vendors that make modems with these chipsets also make other models using other chipsets. Some vendors don't even identify themselves on their modem!

As with any 56k modem, you may experience improvements if you Limit the Maximum Connect Speed or disable 56k. The pages on this site include the appropriate commands for PCTel modems.

Some reports indicate better PCTel connects by changing the maximum speed in Dial-Up Networking to 38,400. [Since this is a software modem, this setting shouldn't have an effect: it's designed to set the rate on a true COM port. Choosing a 38.4k maximum rate with modems using a real COM port will disable 56k.]

PCTel -> Cisco server modem: Cisco remote access has 2 available modems - Microcom and Mica. Recent Microcom firmware should support V.90 with PCTel; Cisco MICA modems didn't support V.90 with PCTel until portware was released at the end of March. There are still problems with PCTel modems - some of which may be resolved  by upgrading to PCTel firmware R765-9k which is available at E-Machines. Another workaround is to limit the PCTel modem to a 26.4k max upstream rate. [The latest beta Cisco code  - - implements a fix by recognizing the PCTel handshake and limiting the server modem receive rate to a maximum of 26.4k.]

Try init string: n0s37=0 - User report of improved throughput with this undocumented string. 

Windows XP, 2000, ME & XP Support - 

All controllerless modems require new Windows 'WDM' drivers to function with these Microsoft operating systems. Microsoft has a web-based Hardware Compatibility List (HCL) that can be used to determine whether a modem is [supposed to be] compatible with Windows2000, NT4, 95 and/or 98. Windows 2000 drivers should work with Windows XP - also see: Windows XP & Modems and Windows ME & Modems. (Note: WindowsMe will support older Win9x drivers.)

Bryan in Wisconsin reports using Dell's Windows XP Driver V 2.40.022 for PCTel MDC V.92 modem with 'generic' PCTel HSP; this driver includes a Modem-on-hold applet and is located here.

For the latest info on Linux support, try Sean's Linmodem Resources.
Currently, the above page has links for IntelHaM Creatix Modem, various PC-Tel drivers, and ESS ISA modems.

Dietrich Radel from New Zealand hosts 2 pages with PCTel Drivers for Linux kernels 2.4.7 - 2.4.20:

SIS 630/635/730 
VIA KM266 (Might work with other VIA chipsets as well)

Dietrich notes - Most problems people have with these (and other PCTel modules) is trying to compile modules when kernel sources (or gcc version) is different to that of the running kernel. Ideally, people should compile the kernel immediately prior to compiling modules to ensure success.

PCTel is developing a Linux driver. download and readme.

Linux drivers are available from: Taicom, Lectron, and Zoltrix.

AT Commands (Also see InitStrings & Limiting Your Connect Speed)

%C0 Disable data compression
%C1 Enable MNP5 compression
%C2 Enable V.42bis compression
%C3 Enable both V.42bis and MNP5
\L0 Use stream mode for MNP
\L1 Use interactive block mode for MNP
\N0 Normal mode; speed control without error correction
\N1 Plain mode; no speed control and no error correction
\N2 Reliable mode
\N3 Auto-reliable mode
\N4 LAPM error correction only
\N5 MNP error correction only
#UD Modem Diagnostics*** See below

Modem Diagnostics: PCTel modems support the AT#UD and AT#UG modem diagnostic commands. However, the diagnostic information is lost when you disconnect the modem. This means that you can make test calls using Hyperterminal, and examine diagnostics while still online (using the escape to command mode +++ sequence which allows you to issue commands while the modem is still online). This cannot be done using DUNs.

Here's a Win9x registry hack from Franc Zabkar that results in the diagnostic information being written to the modemlog immediately prior to hangup:

1. Add s38=0 to DUNs Extra Settings.  (This configures the modem to hangup with no delay when disconnecting.)

2. Backup your Windows registry!* Note that it is possible to make your system unusable or unstable with 'bad' edits to the registry!

  Then, using regedit.exe locate the following key in the registry:


Add a new response key to the right-hand pane as follows:

right-click Responses, then New, Binary Value
call it DIAG <2A4D3263
right-click DIAG and select Modify
type in the following data:
0000 97 00 00 00 00 00 00 00
0008 00 00


3. Locate the following key in the registry:


click Hangup
right-click "1" in right-hand pane, select Modify
change value from ATH<cr> to AT#UDH<cr>

This cause the modem to produce an AT#UD report immediately prior to a hangup (H).

4. Exit regedit

The aforementioned hack will cause lines such as the following to be appended to the end of every modemlog:

<date> <time> - Recv: DIAG <2A4D3263 0=10><cr><lf>
<date> <time> - Interpreted response: MESG

After DUN initiates a software hangup (AT#UDH), it parses up to 20 lines of responses while looking for an OK. As the PCtel modems appear to condense the AT#UD report into about 10 lines, this means that the entire report is captured. 

In the case of Win2K and XP, #UD info is automatically written to the modemlog with at least some of the drivers (see last note below), so a hack is not required. However, to decipher this info there are two freeware utilities:
These archives include a sample Win2000 modemlog which illustrates the format of the DIAG responses.

The above technique could be used for other reports, and for other modem types.

Max Hopper in Ireland reports being frustrated with garbled Modemlog output and too much time on his hands - and came up with discovery that adding 2 registry keys enables Unimodem.dll to correctly decode the DIAG<2A4D3263 responses:

Find the key:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Unimodem\DeviceSpecific\...your modem name here...\Responses  (your modem name here will vary depending upon mfr)

And add New Binary values:
(REG_BINARY): 9e 00 00 00 00 00 00 00 00 00

DIAG  (REG_BINARY) 9e 00 00 00 00 00 00 00 00 00

make sure to include a space after the G in DIAG in both instances.

  *NOTE: The modemlog may also contain unrecognized responses of the form OK<cr><lf>. This is because the registry contains the response string <cr><lf>OK<cr><lf> but not OK<cr><lf>. To rectify this annoyance, add the latter response and assign the following data to it:

0000 00 00 00 00 00 00 00 00
0008 00 00

Note: The PCTel diag strings all begin with DIAG<2A4D3263xxx... There is no space after the G which results in "unrecognized response" in the Modemlog. Therefore the registry must include the "DIAG<2A4D3263" (no spaces) response rather than "DIAG <2A4D3263". Or it could include both, for compatibility with other modems, or with future driver releases.

Some data (eg Rx level) are not correctly reported after the modem has hung up. To capture this data before hang-up, add &D0 to Extra Settings. This will cause the modem to ignore a DTR drop: it will ignore a hardware hang-up request. Instead, the modem will remain on-line until it receives a software hang-up request, (AT#UDH). This command will first capture the #UD report, and then hang-up the line.

NOTE ON WIN2K/XP and ECS Drivers:
The ECS Driver inf file is not configured to support Unimodem Diagnostics (UD) in the modem log. This can be corrected by editing the .inf file (MDMCHIPV.INF) as follows: 

HKR,, Properties, 1, 80,01,00,00, ff,00,00,00, ff,00,00,00, 00,00,00,00, 0f,00,00,00, f7,07,00,00, 00,c2,01,00, C0,DA,00,00

HKR,, Properties, 1, 80,01,00,00, ff,00,00,00, ff,00,00,00, 00,00,00,00, 0f,00,00,00, f7,0f,00,00, 00,c2,01,00, C0,DA,00,00

The above properties has 8 double words of 4 bytes each (each byte represented by a 2-character hexadecimal code separated with comma) in "little endian" format (or 'backwards' - the least significant byte being first). Bit 11 of the 6th double word tells DUNs whether the modem supports the #UD spec. This feature appears to have been introduced with Win2K. 

If the modem has already been installed, it shoud be possible to change the appropriate key in the registry. 

DELL LAPTOPs w/ PCTel Modems - Trouble connecting to Cisco RAS - With PCTel 2304WT chipset, some users having trouble connecting - modem may fail to handshake, or may connect but fail to authenticate. Possible workaround - disable data compression for the modem. (You can do this in the DUNs Connectoid.) 

V.92 Modem-on-Hold: Modem-on-hold is 'built-in' to the earlier V.92 PCTel drivers - there is no separate applet. Richard Kiskis in California reports BestData told him MoH working only once per session is a problem they cannot fix on their PCTel offering:

Richard writes to BestData: MoH only works once during the session. I did NOT check the box to ignore further calls during session. I recently purchased the modem and called myself from my cell phone to familiarize myself with v.92 and MoH. I allowed plenty of time between calls so that the modem was finished retraining.

BestData responds: We have seen this happen with a few systems and it is apparently an incompatibility with the OS, motherboard, and the modem. The only resolution we have for this is to exchange the modem for one with a Conexant chip based modem.

As of Feb '04, Dell supplies V.92 MDC PCTel modems with a 2.50.x driver that does not include built-in modem-on-hold: as with Conexant's other V.92 offerings, modem-on-hold is accomplished with a separate software applet. Dell includes BVRP's NetWaiting MoH software. The 2.50.0043 driver is dated 21-Nov-2002 - and the mdmchipv.inf file can be modified to install with non-Dell-supplied PCTel modems by adding the PCI ID information to the .inf file.

 Version 2.50.0043 drivers from Dell: For Windows XP   and   Windows 2000. Dell also offers a (15mb) User Guide for the PCTel MDC modems it resells.


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