3Com U.S. Robotics 56K Voice User Manual

Also see for U.S. Robotics 56K Voice: User guide Command reference User's guide and reference User's guide and reference User guide

Contents

3Com U.S. Robotics 56K Voice User Manual Manual pdf 27 page image

Internal Modem Installation withWindows 3.x56K Voice Faxmodem Internal - User’s Guide 21Before you start your installation, make sure that you have the followingitems:ModemU.S. Robotics DiskRJ-11 Phone LeadTail LeadMicrophoneAnalogue (Standard) Telephone Wall SocketPhillips Head Screwdriver or ¼” Hex ScrewdriverData/Fax/Voice Communications Software and ManualA Word about COM Ports and IRQsMost computer accessories — a mouse, sound card, enhanced graphicscard, scanner, etc. — require a special connection through which theycan communicate with the computer. For an internal modem, thisconnection is called a communications (or COM) port. Most computershave 1 or 2 COM ports, but they can have up to 4. Although internalmodems do not connect to COM ports directly, they do require a COMport setting, which is determined by the setting on the modem’s COMjumper pins.Each COM port uses an interrupt request (IRQ). An accessory uses anIRQ to get the attention of your computer’s central processing unit (CPU)so that the accessory can perform a task.The computer stops what it is doing, depending on the priority of therequest, to help the accessory perform its task. When two accessoriesshare an IRQ, it is like two people asking different questions in unison toa third person. Just as the person being asked the two questions cannotunderstand either request, a computer can lock up or otherwise fail tocommunicate properly with your modem when there is an IRQ conflict.