July 1995


The Internet is a high-speed network of computers. If you want to use a World Wide Web browser on a PC with Windows to explore "the Web," you need the fastest possible connection to the Internet. However, at this time, the only economical way for individuals and small businesses to connect to the "Net" is with a dial-up telephone line.

Dial-up lines are optimized for voice, not digital information. The fastest modems for dial-up lines send and receive at 28,800 bits per second. Low-cost modems run at 14,400 bits per second. Compare these speeds to the speed of an Ethernet local area network: 10 million bits per second, over 300 times faster.

Using data compression, a modem can send up to four times the data you would expect based on its speed. In other words, 28,800 bits sent in one second might carry as much information as 115,200 bits sent without data compression. The modem at the other end of the line restores the original information.

The point is this: at maximum speed, your computer must receive data four times faster than the modem's rated speed. That means receiving 115,200 bits per second from a "28.8" modem or 57,600 bits per second from a "14.4" modem.

Unfortunately, your computer probably cannot handle such speeds without some changes.


If you have an external modem connected to a serial port, the "UART chip" which controls the serial port should be a 16550, not the older 8250 or 16450. To determine which chip you have, run the program MSD (Microsoft Diagnostics), which should be in your DOS directory. Select COM Ports and you will see the chip used on each port. Ignore any letters after the chip number.

Even a brand-new Pentium computer may very well have one of the older (and cheaper) UARTs. The old chips cannot run fast enough to keep up with today's modems. The solution is to buy a new serial card with a 16550 UART.

If you have an internal modem, the UART is on the modem board. You most likely have the fast 16550 chip, but run MSD to be sure.


The communications software, or "driver," built into Windows is said to lose data starting at about 19,200 bits per second. As we have seen, however, even a 14.4 modem should communicate with the PC at 57,600 bits per second because of data compression. Windows will not be able to keep up.

Some modems come with their own communications drivers for Windows, which may enable you to use higher speeds. A product called TurboCom also provides new drivers.


Many Web pages use graphics, and you will be watching the Windows hourglass a lot, no matter how fast your modem runs. Often, however, the speed bottleneck will not be in your PC at all. The computer sending data to you may be slow, or the network connection between that computer and yours may be busy.

You can watch the lights on an external modem to see when data is coming in. The RD and SD lights represent data being received and sent, respectively. Expect to see data arriving in spurts, separated by rather long pauses. The more data to be transferred, the more frequent the pauses. This pattern of activity suggests slowdowns at the sender's end of the line.

If the modem's data lights are off a lot, greater speed at your end is not likely to make a difference. This often seems to be the case with the Web. File transfers (which use FTP, the file transfer protocol) usually show steadier activity and are more likely to go faster with a faster PC system.


A Web browser is the software you run on your PC to navigate the World Wide Web. The most popular browser is from Netscape.

If you view the same Web page more than once, you may find that it appears very quickly after the first time. That is because the browser saves a copy of the page in memory or on your hard disk. The next time you request that page, the software can display it without reading it again from the Net.

RTG Bills and RTG Timer are trademarks of RTG Data Systems. Other company and product names may be trademarks of the companies with which they are associated.

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