User manual
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3.13 Equipping a Desktop Computer with Multiple Modems
See http://www.sandstorm.net/support/phonesweep/multiport.shtml for up-to-date information on
recommended multi-port solutions.
There are many strategies for configuring a desktop computer to use multiple modems:
• The simplest is to equip your computer with a PCI or USB-based multi-port serial I/O expander and
use external modems.
• Sandstorm recommends SeaLevel’s Versa-COMM 4-port (model 7401) and 8-port (model 7801)
cards (http://www.sealevel.com/
). (Important Note: You must install the Asynchronous driver from
the SeaLevel CD before installing the SeaLevel card. Also, if you are using an old card, or upgrading
to a new OS, please obtain the latest drivers from SeaLevel’s website. You can install multiple
SeaLevel cards on your system (Windows NT does not support the use of multiple multi-port serial
I/O cards).
• 8 Modems: Digi (http://www.digi.com
), has some very good solutions for 8+ port operation,
including the AccelePort and Edgeport USB devices.
• 4 Modems only: You can use two of SIIG’s Cyberserial PCI-Bus High-Speed Dual Serial Port cards
(model # IO1888) (http://www.siig.com/products/io/pci_io.html
).
• Avoid interface cards by Addonix; they have been found to have unreliable software drivers.
• You can also install an ISA-based multi-port serial I/O card and use external modems.
• The most difficult alternative is to install one or more single or dual COM port cards or internal
modems. This requires assigning each COM port or modem to its own IRQ and I/O address.
We recommend using a USB or PCI multi-port serial expander if possible. This avoids any issues
related to PC IRQs and I/O addresses. Otherwise, you may need to remove other hardware to free up
sufficient IRQs and I/O addresses for that which you need to install. You may be able to remove or
disable devices that are unnecessary in a production environment, such as sound cards and infrared ports.
If you have unused devices built into your computer's motherboard, they can be disabled using the
computer's BIOS SETUP utility.
3.13.1 Installation advice for multi-port cards
• When installing SeaLevel cards you must install the Asynchronous drivers before you install the
physical cards. To install the drivers, you can either run setup.exe from the Start->Run dialog box, or
open the index.htm file on the CD. (On the index.htm page, select the Install Software link, and then
go to the Asynchronous section).
• For all other multi-port cards except SeaLevel, install the drivers after you install the hardware.
Make sure you install the correct drivers for your operating system.
• With the Power off, place each card into its slot dead-on (not at an angle) so that all electrical
connections come together at the same time. This will synchronize communication with the PC.
• Push the card gently into each slot. Some PC’s make an audible click when the card is fully in
place.
• When plugging the multi-port card and modems into the octopus cable, be sure all connections
are dead-on. Some connections are very fragile; be very careful how you push the cable onto the
card.