Why do we call it a "radio button" in computing?

You really enjoyed our previous articles about the semantics behind certain terms like "software patches" or "hackers", so here's a new one about "radio" buttons!

Let's start from the beginning, what exactly is a "radio" button?

A radio button is a checkbox that's part of a group, for which only one option can be checked at a time.

These radio buttons, as we see them today in any form, started to become widespread in the graphical interfaces of Apple's Macintosh, released in 1984:

That's great, but we still don't know the origin of the name...

What does it have to do with radio?

The 20th century saw the explosion of radio systems, local and national broadcasting systems and especially the arrival of increasingly sophisticated radio sets.

At first, the sets were only equipped with two dials to choose the frequency and volume, then they became more complex (notably with several AM and FM reception modes).

One of the main constraints of these period radios was changing stations and managing to find the right frequency each time to minimize interference as much as possible.

Fortunately, station memory buttons came along, as in this photo:

When you click a button, you jump directly to the station you had previously saved, but here's the thing, since you can only listen to one station at a time, the inactive buttons had to automatically pop back out.

And that's how the "radio buttons" system used in computing today was born... With one detail left out: the shape.

On radios, the buttons were mostly square or rectangular, sometimes with labels engraved directly on them.

So why are they round today?

Because in reality, Apple popularized a good number of interface elements, but they're not the ones who invented this interface element...

The true first appearance of a radio button

Xerox PARC (for Palo Alto Research Center) is one of the most iconic research centers in the world. Founded in 1970, this is where a good number of computing innovations were born that we still use today.

In 1981, Xerox released THE first computer running with a graphical interface (unlike command terminals), the Xerox Star.

It was for this machine that interface elements were invented, and guess what, you can find "real" radio buttons on it (rectangular and containing text):

Despite its share of innovations, the Xerox Star was a commercial flop for three reasons:

• Its selling price: $16,595 in 1981
• Its slowness
• The lack of spreadsheet software

If you want to see a demonstration of the Xerox Star on video, it's over here!

We know the rest of the story, Apple would buy the patents for graphical interfaces, keyboards, mice,... from Xerox and release its Macintosh, which would be a huge success.

As for radio buttons, they would simply be redesigned to lighten up interfaces and distinguish them from other buttons!