Windows Xp Architecture Vs. Mac Os X Architecture

Windows XP vs. Mac OS X Architecture

Kurt Luchtman

POS420

Irene Giouvanos

May 29th 2006

When looking at the interface of the Mac OS X Operating System and the Microsoft Windows XP operating system many similarities can be seen. The most obvious is the use of blue in the interface. In the core of the systems they both have a micro kernel which addresses thread management, space management and other communications at the system level and is more resistant to attacks from a virus.

Mac OS X is a powerful development platform; it supports multiple development technologies like UNIX, Java, Cocoa and Carbon. It also is host to many open source, web, scripting, database and development technologies. It was build around the integrated stack of graphics and media technologies such as QuickTime, Quartz, Core Image and Core Audio. Mac OS X is based on the Mach Kernel and the BSD implementation of UNIX which were originally incorporated into the NEXTSTEP operating system. Many aspects of the Mac OS X architecture are derived from OPENSTEP / NEXTSTEP which was designed to be an easy transition from one platform to another. At the core of this system is Darwin, an open source UNIX like operating system built around the XNU kernel with standard UNIX facilities available from a command line interface.

Running on top of this core is several proprietary closed source software such as Aqua (the User Interface) and the Finder application. The Aqua interface is the graphical user interface, it uses soft edges, translucent colors, more color and texture to the windows and it controls most of the systems overall appearance. Apple made this decision during a time that most user interfaces were seen as dull and boring. The Finder is a subset of the user interface as it helps navigate through the system and the finder isn't required to be running for other applications to run. The finder helps the user find programs and visually organize data on the computer.

Among the Aqua user interface, Apple also built in Pre-emptive multitasking and memory protection to improve the ability of the operating system to run multiple applications simultaneously without interrupting or corrupting each other. The system can also determine how much RAM should be used for each running application and it can also determine how much of the processor needs to be devoted to the running applications. For example if a picture is being rendered in Photoshop in the background and a user is surfing the web in the foreground, the system will automatically put more of the processors power to the Photoshop application to get the requested job done.

Apple also wants as many developers as it can get for the Operating System; therefore they have created development tools that are included with every copy of the system. One of the most notable programs that is included is called Xcode. Xcode provides interfaces to compilers that support several programming languages such as C, C++ and Java. Because Apple is also in a transition from the PowerPC RISC processor to the Intel X86 processor the Xcode application can compile code for either or both processors, making the compiled application a Universal Binary application.

Windows XP has a microkernel that sits between the Hardware Abstraction Layer and the executive, it provides multiprocessor synchronization, thread and interrupt scheduling and dispatching, trap handling and exception dispatching. The microkernel often interfaces with the process manager and it is responsible for initializing device drivers at the boot sequence that are required to start the system.

The Hardware Abstraction Layer is a layer between the physical hardware of the computer and the rest of the system. It was designed to hide the differences in hardware and to provide a consistent platform to run applications on. It also includes hardware specific code that controls I/O interfaces, interrupt controllers and multiple processors. Windows XP has common functionality including many system utilities such as the Microsoft Management Console and standard system management applications.

Windows XP is a modular system that contains two main layers, a user mode and a kernel mode. The user mode refers to the mode in which the user programs are run such as Adobe Photoshop and Internet Explorer. These programs are limited in terms of what system resources they have access to. The user mode is made up of subsystems capable of passing I/O requests to the appropriate kernel mode drivers by using the I/O manager. Two subsystems make up the user mode layer, the environment subsystem and the integral subsystem. The Environment subsystem is designed to run applications written for many different types of operating systems. Unfortunately these applications