In March 2002, I made this screenshot showing some emulation within emulation inside an emulated PC:
Why? Because it's an achievement to get it to work!
We have macOS 10.1.3 running on a PowerPC Mac. Then there is macOS Classic layer running to run older macOS applications and one of that is SoftPC Professional. Inside that DOS is running. We also have Virtual PC software for MacOS X running there with a Windows 98 emulation. Then inside that it runs Basilisk II with a macOS System 7.5.3. And inside that one, we run Real PC to emulate another DOS.
- Virtual PC translates Intel CPU instructions to PPC.
- Basilisk II translates 68k CPU instructions to Intel.
- Real PC translates Intel CPU instructions to 68k.
Nowadays we still use a lot of emulations or virtualization. A great way to compile code or test applications for other operation systems without carrying a second laptop computer. We virtualize Linux 32 and 64bit variants in VMWare as well as several Windows versions. As the CPU architecture is the same, it is virtualization. Above we have PowerPC apps emulate an Intel CPU to run Intel software. We also virtualize ARM versions of Windows and Linux on a M1 MacBook with Parallels software. And inside the Windows ARM running there, we run Intel based software like FileMaker Pro.
What story do you have to share?