Classic (Mac OS X)

Classic's performance is also generally acceptable, with a few exceptions. Most of an application is run directly as PowerPC code. (This is likely a major reason why Classic is not supported on Intel-based Macs.) Motorola 68k code is handled by the same Motorola 68LC040 emulator that Mac OS 9 uses. Some application functions are actually faster in Classic than under Mac OS 9 on equivalent hardware, due to performance improvements in the newer operating system's device drivers. These applications are largely those that use heavy disk processing, and were often quickly ported to Mac OS X by their developers. On the other hand, applications that rely on heavy processing and which did not share resources under Mac OS 9's co-operative multitasking model will be interrupted by other (non-Classic) processes under Mac OS X's preemptive multitasking. The greater processing power of most systems that run Mac OS X (compared to systems intended to run Mac OS 8 or 9) helps to mitigate the performance degradation of Classic's emulation.Fact|date=September 2008

ee also

*Apple's Macintosh Application Environment
*Apple's Rosetta (binary translation software) - PowerPC emulator
*SheepShaver - PowerPC emulator
*Basilisk II - 680x0 emulator
*vMac - 68000 emulator

References