Precedents
The first known attempt to move to Intel platforms was the Star Trek project from spring 1992 to 1993, a joint effort with Novell to port Mac OS to run on ordinary 486 PCs. It was based on Novell's next in-development version of DR DOS with its pre-emptive multitasker, which provided a hybrid 32-bit/16-bit core system similar in architecture to Windows 3.1 in 386 Enhanced Mode, but without a GUI. The ported System 7.1 ran on top of this environment. While the project was successful with running pre-beta versions it was stopped in 1993 after management and strategy changes. The core system (but without the Star Trek-specific components) was later released as part of Novell DOS 7.
The Macintosh line underwent a similar transition between 1994 and about 1996, when Apple switched from Motorola's 68K series of chips to IBM/Motorola PowerPC processors, developed jointly by Motorola, Apple, and IBM. This took several years, during which Apple produced versions of the Mac OS that could run on either platform, introduced fairly low-level emulation of the 68K architecture by the PowerPC models, and encouraged third-party developers to release "fat binaries" that could run natively on either architecture.
More recently, Apple has transitioned the Macintosh from the earlier Mac OS to Mac OS X. This transition also took a number of years (a small percentage of older Macintoshes still run the earlier operating system), and was facilitated by the inclusion of Classic, an environment in which an instance of Mac OS 9 could be run, permitting the execution of programs that had not been ported to Mac OS X, as well as the introduction of Carbon for Mac OS 9 and Mac OS X, allowing programs to run natively on either system.
Jobs revealed at the 2005 WWDC that every version of OS X had been secretly developed and compiled for Intel processors as well as PowerPC as they were developed; the portability of its predecessor NeXTSTEP had been maintained. It is not publicly known whether Apple maintains current builds for any other architectures although the closely related iOS project runs on the iPhone's ARM architecture.
Read more about this topic: Apple's Transition To Intel Processors
Famous quotes containing the word precedents:
“The Crucifixion and other historical precedents notwithstanding, many of us still believe that outstanding goodness is a kind of armor, that virtue, seen plain and bare, gives pause to criminality. But perhaps it is the other way around.”
—Mary McCarthy (1912–1989)