Universal Binary

As Apple Computers make the transition from PowerPC processors to x86 (Intel) processors, software needs to be made compatible with either processor type, and this software is known as “universal binary.” Universal binary is an executable file that can run natively on either processor type. When a universal binary software disc is placed in a drive on a computer, the OS detects the universal binary in the disc’s header, and boots the appropriate software version depending on the processor in use. This allows software to run at full speed on either processor type with no impact on performance. No additional memory is needed for universal binary software, since only the appropriate copy of the software is loaded. One of the biggest differences between the PowerPC and Intel processors is how multi-byte data is stored. PowerPC chips store the most significant byte first and x86 chips store the least significant byte first. This is called “byte ordering,” or “endian” format. PowerPCs use “big endian,” while Intels (x86) use “little endian.”