This was the first product that let you reach a doctor when you absolutely, positively needed one

Good Advice: The Motorola Advisor, which came out in 1990, was among the first pagers capable of displaying alphanumeric text.

In the early 1990s, when pagers were in their heyday, the Motorola Advisor was the pager of choice.

The first paging systems were introduced in the 1950s, but pagers came into widespread use only in the 1980s, when wireless technology got good enough to make them easy to use. At the time, Motorola was practically synonymous with wireless communications technology.

The early pagers were far smaller, lighter, and more portable than the cellular phones of the day, which were called bricks for good reason. Typical pager customers wore the devices on their hips and worked in medicine, emergency care, and other quick-response professions.

Early pagers mostly lacked screens, which meant that responding to a page required two calls. When the unit buzzed or beeped, users had to go find a phone, inevitably a landline. They’d first call a pager service to get the phone number the caller had left, and then call the caller.

Pager makers tried several approaches to avoid this problem. Some built models that would allow callers to leave a voice message that could be stored on the pager and played back by the user. Others incorporated tiny screens that could display either a phone number or a numerical code. People compiled lists of codes they would share with callers and other pager users. In this one, 41 means “call me,” for example, and 53 means “thank you,” and so on.

By the early 1990s, roughly 3 million people were using pagers, by some estimates. Many of the new customers had merely a desire rather than a need to be constantly in touch—executives, for instance. By 1993 Motorola’s user manual for the Advisor II noted that the product was “ideal for demanding business environments.”

The original Advisor, released in 1990, was among the first pagers to provide alphanumeric messaging—up to four lines of text with up to 20 characters per line. It could be set to receive not only individual pages but also up to three additional group pages. It also included an alarm clock function. It was compact, measuring 18.5 by 55 by 81 millimeters, and ran on a single AA battery.

Alphanumeric messaging unlocked the full potential of the pager. Often you could send enough information in one 80-character message to ensure that no callback was required. In retrospect, it could be considered a prototype for text messaging, with the same advantages of utility, convenience, and brevity. In the mid-1990s, the number of people using the devices skyrocketed, with estimates ranging from about 25 million to 61 million.

Motorola made two Advisor models that could communicate on different combinations of UHF, VHF, and 900-megahertz bands (the frequency was user selectable). They offered at-the-time blazing fast transmission rates of 1600, 3200, or 6400 baud. The communications protocol was a one-way system called Flex; it was created by Motorola and used primarily for its pagers (a later version, called ReFlex, was two-way). The Advisor’s user manual helpfully suggested, “Include your pager number on business cards and on your answering machine message.” Wow. Remember answering machines?

A few years later, smartphones—and actual text messaging—began to supersede pagers. Nevertheless, paging lives on. To this day, some doctors still use them, because their messages are more secure and their transmission is more reliable.