Practical Peripherals PM9600. (modem) (Evaluation)
by Richard C. Leinecker

Macros and programming make telecommunications faster, but how about getting the information across the telephone lines more quickly--say, four times faster than the standard 2400-bps modem? I had a chance to try out the Practical Peripherals PM9600 modem and liked it so much I bought one for myself. I've installed a variety of modems for COMPUTE's staff, but this one really grabbed my attention. It was easy to install and configure, and it worked perfectly the first time I used it.

Before you consider buying the PM9600, ask yourself if you need a 9600-bps modem. Although theoretically it's four times faster than a 2400-bps modem, that's true only when your computer is talking directly to another computer or when you're on a bulletin board system. When you're connected to online services, delays introduced at every stage of the connection will reduce your effective transmission rate to something less than four times the rate of a 2400-bps modem.

Here's how 2400 bps and 9600 bps compare on my computer when I download files from GEnie. At 2400 bps, the transfer rate is around 138 characters per second (cps); at 9600 bps, it's about 340 cps. That's roughly 2-1/2 times as fast.

Bear in mind, too, that 9600-bps connect charges are greater. You pay a higher hourly rate when connected at the faster speed. However, you'll still end up saving if you're downloading many files. And it's an even greater savings if you're paying long-distance charges.

Another good point: This internal modem is incredibly simple to install and run. I opened up my computer and removed the old modem; then I looked at the back of the Practical Peripherals modem where the COM port switches are located (and thoughtfully marked) to make sure it was set to COM 1. After inserting the card in a slot, I closed the computer and turned it on. I ran my telecommunications software, set it for 9600 bps, and took off. I experienced no interrupt or IRQ conflicts, had no oddball initialization strings to deal with, and faced nothing incompatible or out of the ordinary.

How did the modem work? Great. You might expect line noise and extraneous garbage to enter the data stream, since the transfer speed is much greater, but I didn't find that to be true. In fact, I experienced less line noise with this modem than with some 2400-bps modems I've used. It seems that Practical Peripherals' system of noise filtering is up to the task of the extra speed.

These modems are great for remote-control computing, too. For regular system use like reading messages, though, a 9600-bps probably isn't worth the money unless you're impatient and willing to pay for fast menu and textfile updates.

If you're thinking about buying a modem or upgrading the one you have, though, consider the PM9600. It's an excellent choice.