User manual

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If checkmodems.exe finds the modems, but PhoneSweep says it can’t find the COM ports, please verify
which COM ports checkmodems.exe reports finding modems on, then go to the PhoneSweep options
Setup->Modems sub-tab. If your modems are not set to the same COM ports that checkmodems.exe
reports, you can change the COM ports by clicking on the drop down menu in the COM port column next
to each modem.
3.12 Configuring your PC to support 4 or more Modems
Most Windows-based PCs today are delivered with one or two serial ports, COM1: and COM2:. The
Windows operating system allows up to four serial ports to be addressed through the standard COM port
serial driver. Unfortunately, the task of actually getting a standard PC to recognize 4 or more serial ports
is complicated by history and hardware limitations.
3.12.1 IRQs and I/O addresses
Personal computers have grown more complicated in recent years. Today's laptops and desktops are
equipped with sound cards, Ethernet cards, infrared interfaces, and more. Unfortunately the PC's IRQ
(interrupt request) system still offers only 16 IRQs. Fortunately, a variety of techniques have been
developed to "share" IRQs between multiple devices. Newer PCI-based interface cards can "share" a
single IRQ, but older 8-bit and 16-bit cards that use the ISA bus cannot share IRQs.