It already contains a compatible ROM file (Mac_OS_ROM.rom), a ready 250MB disk image on which Mac OS 9.0.4 is already fully installed (as well as an optional empty 30GB, yes 30 gigabytes, disk image to accomodate heavy disk space use). This bundle was put together by 'that-ben' and is intended to be the easiest possible for starters. SheepShaver is not perfect (it cannot run MacOS 9.1 or 9.2), but enables users to run the vast majority of PPC software for Macintosh on their PC, which is all things considered, extraordinary, especially back in the year 1998. SheepShaver started as a commercial project in 1998 but is now open source since 2002. SheepShaver is a PowerPC (PPC) emulator which allows you to run Mac OS 7.5 up to Mac OS 9.0.4 on various platforms, such as on Windows. What is SheepShaver PPC emulator (for Windows + Mac OS X)?