In summary, the user needs a direct DMG link for macOS Yosemite 10.10.5. The answer should guide them to official Apple sources first, mention possible methods like checking App Store Purchases, Apple Developer downloads, and trusted archives while emphasizing the importance of legal and safe practices.
Also, there's the Apple Developer website where developers can access older versions. If the user has access to a developer account (either personal or company), they can download from there. But if they don't have one, that's another hurdle. mac os x yosemite 1010 5 download dmg link
But where can someone legally get macOS Yosemite? Apple typically provides older OS updates through their App Store archives. The main official source would be the Mac App Store. However, accessing older versions can be tricky because Apple often removes them from their site. If the user has already downloaded Yosemite before, they can find it in their Purchases section under the App Store. If not, they might need to search Apple's support articles or developer pages. In summary, the user needs a direct DMG