Apple Computer's personal computer based on the PowerPC, introduced on 1994-03-14. The Power Mac G4 (Quicksilver 2002) was the first Power Mac to clock at 1 GHz. In mid-2003, the Power Mac G5 was released, the first Mac to be based on a 64-bit architecture. IBM manufactured the CPU for this new model. The clock speed was initially 1.6 GHz but a dual 2 GHz system was available in September. Existing 680x0 code (both applications and device drivers) run on Power Mac systems without modification via a Motorola 68LC040 emulator. The performance of these unmodified applications is equivalent to a fast 68040-based Macintosh, e.g. a fast Macintosh Quadra. The Power Mac runs Macintosh operating system from System 7.5 to Mac OS 8.5.