The word modem isn’t some arbitrary acronym. It’s a contraction of modulator-demodulator. It describes exactly what the hardware does. It takes digital data and modulates it into a signal that can travel over a phone line. The receiving end demodulates that signal back into digital data. Wireless modems do the same thing but use radio waves instead of copper wire.
This technology didn’t appear out of nowhere. It emerged in the 1960s. The goal was simple. Let terminals connect to mainframes over telephone lines.
In those early days, businesses rarely owned their own computers. They bought time from time-shared computing facilities. You’d dial in with a dumb terminal. This was just a keyboard and a screen. No processing power. Just input and display. The DEC VT-100 was the gold standard. It displayed 25 lines of 80 characters. When you typed a key, the modem sent the ASCII code to the central computer. The computer processed it and sent the character back so you could see it on your screen.
It worked at 300 bits per second (bps).
That sounds incredibly slow today. It was acceptable then. Why? Because 300 bps is about 30 characters per second. Humans can’t type or read faster than that anyway. The bottleneck wasn’t the connection. The bottleneck was your fingers.
Then came the personal computer era in the late 1970s.
Bulletin board systems (BBS) took over. Enthusiasts set up computers with modems and BBS software. Users dialed in using terminal emulators on their PCs. These emulators mimicked the behavior of physical dumb terminals like the VT-100.
For years, people were happy with 300 bps. That changed when file transfers started.
Trying to download a large program or image at 300 bps was intolerable. The speed had to increase. Modem speeds climbed in roughly two-year intervals:
- 300 bps dominated from the 1960s until about 1983
- 1200 bps gained traction in 1984 and 1985
- 2400 bps followed
- 9600 bps arrived in late 1990 and early 1991
- 19.2 kilobits per second (Kbps)
- 28.8 Kbps
- 33.6 Kbps
- 56 Kbps became the standard in 1998
- ADSL emerged in 1999 with theoretical speeds up to 8 megabits per second (Mbps)
“Once people started transferring large programs and images to and from bulletin board systems, however, 300 bps became intolerable.”
We moved from blinking cursors and mechanical keyboards to streaming video and cloud computing. The modem was the bridge. It started as a translator for text. It ended up moving the world’s data.
How fast will they get next? The theoretical ceiling keeps rising. The hardware keeps shrinking. But the core idea remains. Convert data to signals. Send it. Convert it back.
We’re still waiting for the next leap.
