Apple’s MacBook Touch Bar is actually a mini Apple Watch

Apple unveiled its Touch Bar addition to the MacBook Pro yesterday. While the company spent time demonstrating its ability to change function keys on the fly, or light up its display with colorful emoji, Apple didn't talk about what's really powering its Touch Bar. Irish programmer and developer Steven Troughton-Smith has discovered that the Touch Bar is actually a mini Apple Watch.

"From everything I can piece together, the T1 chip in the new MacBook Pro is a variant of the system-on-a-chip used in the Apple Watch," explains Troughton-Smith, in an interview with The Verge. "Running watchOS on the T1 lets the Mac benefit from Apple's deep work on iOS embedded security, as the T1 gates access to the Touch ID sensor and, from the looks of it, the front-facing camera in the new MacBook Pro too."

---

Apple has selected watchOS to power the Touch Bar, but that doesn't necessarily mean we're going to start seeing Apple Watch apps appear above the keyboard. The Touch Bar has a 25MB ‘ramdisk' that's used to boot and control the hardware, so it doesn't have the full version of watchOS required to run apps and the full UI. Apple is providing developers with APIs to create apps that interact with the Touch Bar, and a few big names have already got theirs ready. "There's no way for multiple apps to drive the bar layout at the same time," explains Troughton-Smith, so apps won't be able to trigger notifications or take over the Touch Bar in the background.

Apple's Touch Bar has a lot of potential

What's really interesting about the new MacBook Pro running a mini Apple Watch is the possibilities for the future. Apple just added an embedded iOS computer with a touchscreen to its MacBook range, so that opens the doors for future experiments. "Today it might be similar to an Apple Watch in capability, but there's so much potential for this to grow," says Troughton-Smith. "The Touch Bar theoretically could run while the rest of the machine is turned off, so you get all the low-power and security benefits of an iOS device, without having to switch to ARM completely on the desktop."

That could mean Apple could bring actual iOS features, apps, and touch functionality over to the Mac without having a true touchscreen. "Perhaps someday it could run a higher class processor, like Apple's A-series chips, and allow macOS to 'run' iOS apps and Extensions, like iMessage apps, or manage notifications, system tasks, networking, during sleep, without having to power up the x86 CPU," speculates Troughton-Smith. That possibility makes Apple's Touch Bar experiment a lot more interesting, and it could make it a lot more like Microsoft's failed attempt to popularize Windows SideShow, a way for developers to extend apps and notifications to small screens on laptops while they were powered off.