Buying a 56K modem, also known as a dial-up modem or analog modem, can be confusing. There are several different form factors and processor options to choose from.

For example, should you buy a PCI Modem, a USB Modem, or a Serial Modem? What is the difference between USB 1.0 and USB 2.0? Do you need a controller-based modem, a controller-less modem, or a soft modem?

This brief tutorial will explain the different modem options available to help you choose the correct modem for you!

• Hardware modems, also known as a "controller modems" or "hardware-controlled modems"
• DSP-based modems, also known as a "controller-less modems"
• Software-based modems, also known as "softmodems" or "win modems"

Of these three types, hardware modems are the most powerful. DSP-based modems are the second most powerful, and softmodems are the least powerful.

In order to send and receive data over the Internet or a network, modems have to process outgoing and incoming data streams. Hardware-based modems have special hardware chips onboard that do most of this processing. Because of this, hardware-based modems do not have to rely on sending information to and from the computer’s central processor, which can slow down transmission speeds and place a heavy drain on the computer for performing other tasks.

DSP modems have some of the processing capability of hardware modems, but not all. As a result, they are faster than softmodems but not as fast as hardware modems.

Softmodems must rely almost entirely on the computer’s CPU to process the data. As a result, they are the slowest modems and place the greatest burden on the CPU, which may slow down other applications running on your PC.

How you are going to use the modem generally determines which is the best processor type for you:

• Hardware Modem: If you will use your modem daily for several hours or more you should most likely buy a hardware-based modem.
• DSP Modem: If you plan to use your modem daily for an hour or more then a DSP modem would be the best choice.
• Softmodem: If you plan to use your modem for simple Internet access a few times per week, a softmodem is probably the most suitable.
  

You should also consider your computer’s processor speed. In general, the slower your computer’s central processor is, the more powerful a modem you should purchase. This is because less powerful modems put more of a strain on the computer’s own processor. So you should only use a weaker modem (softmodem) if you have a fast central processor. You can check your processor’s speed by consulting the documentation for your PC. You can also check within Windows by selecting "Properties" on the "My Computer" icon.

Here are some general guidelines:

• 300 MHz or less: A hardware controlled modem would be best.
• 300 MHz - 1.0 GHz: DSP controlled modem would be best.
• Over 1.0 GHz: Softmodem would be acceptable.

56K modems come in 5 different form factors:

1. USB Modem (external)
2. External Serial Modem
3. PCI Modem (internal)
4. ISA Modem (internal)
5. PCMCIA Modem or Laptop Modem (external)

To purchase the correct form factor, you should consider what options are available for your computer, the performance required, and the ease or difficulty of the installation.

1. USB Modem: If you have a USB port available (either USB 1.0, USB 1.1, or USB 2.0) you might consider a USB modem. They are the easiest modems to install, since they do not require you to open your computer case. USB modems can usually be found in DSP and hardware-controlled versions.
2. External Serial Modems: Like USB modems, serial modems are external and easy to install. They are usually hardware controlled and offer excellent performance.
3. PCI Modems: These are the best-selling modems, and are generally the kind of modem that comes installed a new machine. PCI modems come as either DSP modems or softmodems. You should only purchase a PCI modem if you are comfortable opening your PC case and installing a new PCI card.
4. ISA Modems: These are also internal modems. To use an ISA modem, your PC must have an available ISA slot. These slots or usually only found on older PCs. Consult your system documentation to verify your slot type. These are usually hardware controlled modems, sometimes DSP-based.
5. PCMCIA Modems or Laptop Modems: This is a "card"-type modem that can be used only with a laptop. If you have both a laptop and a desktop PC, you might want to purchase a USB modem instead, since it can be used with either type. For simplicity and ease in traveling, a PCMCIA modem is the best choice.

Modem Vendors: Diamond Multimedia, Best Data Products, U.S. Robotics
Some of the leading vendors for 56K modems are Diamond Multimedia, Best Data Products, and U.S. Robotics.

• Diamond Multimedia’s SupraMax modems have been a leading brand of modems for more than a decade.
• Best Data Products has been offering high quality 56K modems for over 20 years. Their SmartOne modems are known for their value and durability.