AT Command Reference Summary
A full list of the modem commands. Source: Modems.com
Checking Line Quality
A step by step guide on how to check your telephone line quality for high speed connections
Extended AT Command Sets
A very useful reference, includes modem commands, dial command modifiers, serial port control, and more.
Extra Initialization String for Modems Is Limited to 40 Characters
Microsoft Knowledge Base Article: 311941 -
When you try to configure an extra initialization string for a modem, you may be unable to add a string that is longer than 40
characters. (updated 182002)
Fax Standards and Protocols
An overview of Fax machine classifications and corresponding fax modem classes.
List of all Modem manufacturers
Complete list and links to over 140 modem manufacturers. Source: modems.rosenet.net
All about UART's
Helpful guide to Universal Asynchronous Receiver/Transmitters, which are large scale integrated circuit that contain all the software programming necessary to fully control the serial port of a PC. Source: 3COM
Installing an ISA Bus Modem in an EISA Bus Slot
t
Source: 3COM
Serial Cable Pinouts
Source: 3COM
Known Issues and Bugs:
Cannot Use U.S. Robotics 56K Voice Faxmodem USB in Windows 2000
Microsoft Knowledge Base Article: 257738 - Windows 2000 may not be able to locate drivers for a U.S. Robotics 56K Voice Faxmodem USB that is connected to a Universal Serial Bus (USB) port, even though drivers for this modem are included with Windows 2000. (updated 8/10/2000)
Modem Not Detected in Windows 2000
Microsoft Knowledge Base Article: 199184 - Your keyboard or other devices may stop working, and you may experience other unexpected results such as loss of display color depth and resolution. A Plug and Play modem is not automatically detected. When you try to install the modem
manually, Setup gets stuck in an endless loop and the Hardware Installation Wizard becomes unresponsive. Debugger output continuously prints: "PNP_EnumerateSubKeys caused an exception (1717)." The only way to stop this is to reboot. (updated 962000)
Modem Powers Off When It Is Not in Use
Microsoft Knowledge Base Article: 275042 - If you have a secure PC Card modem or a similar device that requires you to type a password before it is enabled and you connect to the modem when you start your computer (for example, by using HyperTerminal),
modem, the modem is automatically powered off by Windows. When
this occurs, Windows does not retain your password and you must
retype it to enable the modem again. (updated 272001)
OEM Preinstallation with a Driver-Based Modem Uses Incorrect Path to the Modem.sys File
Microsoft Knowledge Base Article: 252667 - While in the GUI-mode phase of Setup, you may receive an error message that prompts you to provide the location of the Modem.sys file. (updated 8/29/2000)
Problems Using Plug and Play Modem with Windows 2000 on Compaq Prosignia 200 or 720
Microsoft Knowledge Base Article: 280365 - After you install Windows 2000 on a Compaq Prosignia 200 or 720 computer with a Plug and Play ISA modem, a COM port may appear in Device Manager with a yellow exclamation point with a "Device failure" (code 10) status. For example, this may (updated 1262000)
PCTel V.90 K56 Hex HSP PNP Modem Does Not Work After Installing Windows 2000
Microsoft Knowledge Base Article: 228012 - After you install Windows 2000, your PCTel V.90 K56 Hex HSP PNP modem may not function. The modem appears as an unknown device in Device Manager. (updated 962000)
Standby or Hibernation Mode Disconnects ISDN, Modem and VPN Connections
Microsoft Knowledge Base Article: 227618 - When you manually put a computer running Windows 2000 into a Standby or Hibernation mode, any ISDN, modem, or VPN connection is disconnected. (updated 962000)
Using Virtual COM Port Dials Modem as Pulse Only
Microsoft Knowledge Base Article: 263643 - When you connect to a modem pool by using the Modem Sharing service from a Windows 2000-based computer, the modem may not respond or may respond incorrectly by not dialing, dialing only in pulse mode, or without using other initialization
strings (updated 10/25/2000)
Xircom CreditCard Ethernet+Modem 28.8 and 33.6 May Hang with Heavy Use
Microsoft Knowledge Base Article: 246997 - When you use a Xircom CreditCard Ethernet+Modem 28.8 adapter or a Xircom CreditCard Ethernet+Modem 33.6 adapter on a portable computer running Microsoft Windows 2000 Professional, the adapter may stop responding (hang) under heavy
use. (updated 12/29/1999) |