Re:Windows 95 went the extra mile to ensure compatibility of...
by solardev on Monday December 26, 2022 @06:44PM
(#34143204)
Not only that, they built an entire x86 and x64 emulator into Windows for Arm, so that (for example) if you install Parallels on a M1/M2 Mac and run Windows on it, you're getting the special Windows for Arm build, but many of your apps will still run because of the built in emulation of Windows.
It's just crazy compared to how much software just completely breaks between different macOS releases with no recourse, or have to be recompiled and reinstalled from scratch on Linuxes. Microsoft's bad at a lot of things, but they deserve a huge amount of credit for their backward compatibility on Windows...
https://learn.microsoft.com/en-us/windows/arm/overview
Edit: Seems that emulation system also uses WOW64! https://learn.microsoft.com/en-us/windows/arm/apps-on-arm-x8...
WoW64 makes 32-bit programs work under 64-bit Windows by providing an entire 32-bit copy of the 64-bit operating system, and then transparently redirecting reference calls made by 32-bit programs to them instead.
It's simple in design, brute force in execution, and practical in results. I hope Microsoft never changes their backwards compatibility philosophy; other operating system vendors should strive to be like them.