That is, it enables you to run PowerPC Classic Mac OS software on your computer, even if you are using a different operating system. The only emulator known to run this software is the ShoeBill emulator. It was introduced on May 13, 1991, by Apple Computer. On other systems, SheepShaver provides the first PowerPC G4 emulator, though without MMU, to enable the execution of Mac OS Classic. How this emulator achieves good performance in the browser Drag and drop … The plan is to implement System 7 + Color QuickDraw, 68040 instruction set, more hardware emulation, etc. The Mac 68k emulator is a software emulator built into the ROMs of PowerPC-based Macintosh models. Then I moved up to a Macintosh IIsi running System 7.