Modems

There’s a rather standard science fiction situation, based loosely on some of the oddities of quantum physics (the quirks of quarks, one might say), that postulates a whole other universe co-existing with ours, sharing the same space, but unseen.

Well, in a sense this “parallel” world is already accessible, though not as a science-fictional “alternate reality.” This complex world that many people never see is the world of computer telecommunications, and it exists all around you right now.

You’re probably used to the idea that today money is transferred from computer to computer across the continent or around the world, or that police can use computers in their cars to obtain information on criminals from computers located miles–even hundreds of miles–away.

But computer telecommunications involves a lot more than just business, government and security institutions. It also involves millions of individuals who are discovering that with their computer, they can “reach out and touch” other people and information world-wide.

Most of this telecommunicating is done on ordinary phone lines, using devices called “modems,” which stands for “modulator-demodulator.”

Computers are basically vast collections of on-off switches, and therefore use binary code–a code with only two signals, “on,” or 1, and “off,” or 0.

A modem takes binary signals and converts them into electrical pulses that can travel along phone lines. In fact, early modems were devices designed to accept an ordinary telephone receiver. The modem would produce a sound, a kind of warble in which high notes were the ones and low notes the zeroes of the binary signal. The receiver would transmit that sound, and the modem on the other end would “hear” it and translate it back into binary.

Today’s modems usually plug right into the telephone jack and don’t create an audible sound, but if a human answers the phone instead of another computer, he or she will hear that same warble (until the transmitting computer realizes the futility of trying to talk to a stupid human and hangs up).

The speed with which information is transmitted ranges from about 300 bits per minute (a bit is one “on” or “off” signal), to a million or more. The speed is limited by the equipment being used and by the communication channel itself.

The volume of information the channel can carry is called its bandwidth. Think of it as a waterpipe: you can get a lot more water through a wide pipe than a narrow pipe. If you try to put lots of water through a narrow pipe, it will back up. In the same way, if you try to put lots of data through a narrow-bandwidth communications channel, the data is going to take a long time to get through.

Ordinary telephone cables have a moderate bandwidth that isn’t all used by voice communication, leaving room for some computer use, as well. But for maximum efficiency, you need a dedicated computer line, so you can use the entire bandwidth to transmit data, and you also need something better than metal.

That “something better” is fiber-optic cables. In these, hair-like glass fibres carry enormous amounts of data as pulses of light instead of electricity. They have a much higher bandwidth than ordinary cables and they lose a lot less in transmission. Increasingly they’re the communication channel of choice, not only for computers, but for voice and even for television. (And by the way, Saskatchewan–specifically SaskTel–is a leader in fiber-optic technology.)

And, of course, if you really have to send data a long way, you can always make use of the communications channel with the widest bandwidth of all: space. Enormous numbers of messages of all kinds are sent around the world with the help of satellites.

OK, so that’s HOW computers can exchange information around the world, but what kind of information is being exchanged?

You name it. Scientific data, stock reports, computer programs, genealogical information–anything and everything. The computer puts a world of knowledge at the fingertips of anyone with a computer and a modem (and the ability to pay long-distance and access fees, but that’s another story).

But most interestingly of all, the computer puts individual humans in touch with each other in a brand-new and exciting way.

Regina alone has more than 30 computer “bulletin boards,” where people with computers and modems meet in an electronic version of the old town hall (or, maybe, these days, that should be “mall”). They exchange computer programs, play games, post “For Sale” notices–and they talk. Boy, do they talk! They argue about politics, religion, sports, and who said what to whom and when; they tell abysmal jokes (and some that are even pretty good); and, in general, they “hang out.”

Some of these boards are operated by computer stores and serve as a source of information about the particular brands of computers sold, but many others are operated by individuals.

Some are part of larger computer telecommunication networks that spread worldwide, allowing users in Regina or anywhere else to participate in huge ongoing discussions with dozens or hundreds of other people from all over North America and abroad concerning everything from the most esoteric technical problems to the latest news on Star Trek.

You see what I mean about an alternate world? Computer telecommunication has created an electronic society invisible to most of us most of the time. But more and more people are becoming part of it, and more of more of it surfaces in the “real” world all the time, in business, education and entertainment.

In that sense, this alternate world isn’t “parallel,” like those of science fiction; it’s on a converging course.

In fact, it’s taking over–just one more victory for the computer revolution.

Permanent link to this article: https://edwardwillett.com/1991/02/modems/

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