老款的macbook 如何使用随航（sidecar)

Also, 2015 MacBook Pros are explicitly not supported for SideCar even when running supported macOS versions like Big Sur and Monterey on them. Sidecar requires a 2016 or later MacBook Pro.

按照原系統設計在「顯示器」後方應該有個sidecar入口，然而被 蘋果 隱藏了。 ... 所以根據原設定舊設備搭載首個開發者版本暫時無法體驗到mac與ipad連動的體驗。

Thanks to Free-Sidecar, you can expand Sidecar compatibility to additional iPad and Mac models that are otherwise not officially supported by Apple for the feature. Sidecar is one of the most useful features for Mac and iPad users, allowing an iPad to ser

Starting with macOS Catalina, Sidecar is no longer available to turn your iPad into a second monitor since it was removed in this update. This wikiHow teaches you how to enable Sidecar on macOS Catalina.

还是忍不住升级了catalina，实际上是为了体验一些新的特性，在这些特性中我最想体验的是 sidecar，日常使用的时候，我很需要一块副屏，作为调试或者输出窗口使用，所以这次升级主要是为了让我的ipad pro 发挥生产力。