Usuario:Xiuhcoatl Xiuhuitl/borrador

Rosetta
Información general
Tipo de programa	PowerPC traducción binaria
Desarrollador	Apple Inc.

Rosetta es un traductor dinámico binario para Mac OS X que permite a muchas aplicaciones PowerPC correr en ciertas arquitecturas Intel de las computadoras Macintosh sin modificaciones. Apple publicó el software Rosetta en 2006 cuando hicieron la transición de las platformas Macintosh basadas en procesadores PowerPC a la arquitectura de conjunto de instrucciones (instruction set architecture,ISA) de Intel. El nombre de "Rosetta" es una referencia a la piedra rosetta, el descubrimiento que hizo posible comprender y traducir los jeroglíficos egipcios.

Rosetta está basada en la tecnología QuickTransit.​ No tiene interfaz de usuario (graphical user interface), lo que llevó a Apple a describir la aplicación de Rosetta como "el software más sorprendente que jamás se ha visto".​

Rosetta inicialmente estuvo incluido en el sistema operativo Mac OS X v10.4.4 "Tiger", la versión que fue inicialmente sacada a la venta junto con los primeros modelos de arquitectura Intel de Macintosh.​

El software de Rosetta no está instalado por omisión en la versión Mac OS X v10.6, conocido también como "Snow Leopard", pero puede conservarse como una opción mediante el instalador o haciendo uso de la aplicación actualización de software de Apple (Apple Software Update) para usuarios que necesitan correr aplicaciones basadas en PowerPC applications.​

Rosetta no está incluido ni soportado por la versión Mac OS X v10.7 "Lion" or superior. Por lo tanto, con Lion y futuros lanzamientos, la actual plataforma Macintosh no tiene soporte con aplicaciones de PowerPC.​

Compatibility

Plantilla:AppleIntel Rosetta is part of Mac OS X for Intel operating system prior to Lion. It translates G3, G4, and AltiVec instructions; however, it does not translate G5 instructions. Therefore, applications that rely on G5-specific instruction sets must be modified by their developers to work on Rosetta-supported Intel-based Macs. According to Apple, applications with heavy user interaction but low computational needs (such as word processors) are well suited to translation via Rosetta, while applications with high computational needs (such as raytracers, games, or Adobe Photoshop) are not.​ Pre-existing PowerPC versions of Apple "Pro" media-production applications (such as Final Cut Pro, Motion, Aperture, and Logic Pro) are not supported by Rosetta and require a "crossgrade" to a universal binary version to work on Rosetta-supported Intel-based Macs.

Rosetta does not support the following:​

• The Classic environment, and thus any non-Carbon application built for Mac OS 9 or earlier
• Code that inserts preferences into the System Preferences pane
• Applications that require a G5 processor
• Applications that require precise exception handling
• Screen savers
• Kernel extensions and applications that depend on them
• Bundled Java applications or Java applications with JNI libraries that can’t be translated
• Java applets in Rosetta-translated applications, meaning that a native Intel web browser application, rather than a legacy PowerPC version, must be used to load Java applets

The reason for Rosetta’s reduced compatibility compared to Apple’s earlier 68k emulator for PPCs lies within its implementation: Rosetta is a user-level program and can only intercept and emulate user-level code, while the older emulator was integrated with the system at a much lower level. The 68k emulator was given access to the very lowest levels of the OS by being at the same level as, and tightly connected to, the Mac OS nanokernel on PPC Macs (later used for multiprocessing under Mac OS 8.6 and later), which means that the nanokernel was able to intercept PowerPC interrupts, translate them to 68k interrupts (then doing a mixed mode switch, if necessary), and then executing 68k code to handle the interrupts. This allowed lines of 68k and PPC code to be interspersed within the same binary of a fat application. While a similar effect could likely have been achieved for Mac OS X by running Rosetta within XNU, Apple instead chose to implement Rosetta as a user-level process to avoid excessive debugging and the potential for security issues.^{[cita requerida]}

See also

• Mac 68k emulator - lower level program used for a similar purpose during 680x0 to PowerPC transition
• Universal binary - combined PPC/Intel applications that run natively on both processors
• Fat binary - combined PPC/68k application that ran on older Macintoshes

External links

• Apple Rosetta Web site en Wayback Machine (archivado el 7 de enero de 2011).
• Transitive Corporation web site en Wayback Machine (archivado el 14 de septiembre de 2008).
• Rosetta compatibility index