We have controls that mimic the actual radio buttons in the form of toggle buttons (buttons that stay depressed after pressing them), but in many APIs the programmer needs to toggle the press state of all other buttons in the group to use them.

Preset radios came in a huge variety and some of them were actually round. Car radios (the radios that have stuck around the longest) need big and bulky buttons so you can operate them without taking your eyes off the road, but some home radios had smaller, circular buttons instead.

The "radio" buttons I used as a kid were small, rectangular sticks poking out of a metal plate that you pushed in. Every brand had their own shapes and designs. Unfortunately, I can't find any pictures of older radios on the internet because every image searching site seems to have been overtaken with badly generated AI art, stock photos, and cheap, plastic "retro vintage" Amazon listings.