If you compare today’s computers to the ENIAC, you’ll see the biggest difference is size. We may be saying the same thing about iPhones someday soon as scientists have built the first carbon nanotube computers.

Someday we may look back on today’s iPhones and laptops as huge, clunky devices with outdated chips made of silicon that was long ago replaced by carbon nanotubes. Tens of thousands of the tiny tubelike structures can fit inside a human hair, and now scientists have created the first carbon nanotube computer — a big step toward miniaturizing our electronics even further.

While it pales in comparison to today’s computers, the bare-bones machine works. It runs a basic operating system and can freely switch between two programs — one that counts in a loop and another that sorts numbers.