Games - Mac OS

	Games - Mac OS

Mac OS, which stands for Macintosh Operating System, is a series of graphical user interface-based operating systems developed by Apple Computer for their Macintosh line of computer systems. The original Mac OS is often credited for popularizing the graphical user interface successfully. It was first introduced in 1984 with the original Macintosh, the Macintosh 128K.

Apple deliberately played down the existence of the operating system in the early years of the Macintosh to help make the machine appear more user-friendly and to distance it from other operating systems such as MS-DOS, which were portrayed as arcane and technically challenging. Apple wanted Macintosh to be portrayed as a system "for the rest of us". Therefore the term "Mac OS" didn't really exist until it was officially used during the mid-1990s. The term has since been applied to all versions of the Mac system software prior to this as a handy way to refer to it when discussing it in context with other operating systems.

Earlier versions of the Mac OS were compatible only with m68k-based Macintoshes, while later versions were also compatible with the PowerPC (PPC) architecture. Most recently, Mac OS X has become compatible with Intel's x86 architecture.

Versions

The Macintosh operating system initially consisted of two pieces of software, called "System" and "Finder", each with its own version number. They were bundled for upgrades as "System Software" with a single version number for each combination. This was formally shortened to "System" (and the component version numbers synchronised) with "System 6". System 7.5.1 was the first to include the Mac OS logo (a blue variation of a smiley face), and Mac OS 7.6 was the first to be named "Mac OS" (to ensure that users would still identify it with Apple, even when used in "clones" from other companies).

Until the advent of the later PowerPC G3-based systems, significant parts of the system were stored in physical ROM on the motherboard. The initial purpose of this was to avoid using up the limited storage of floppy disks on system support, given that the early Macs had no hard disk. (Only one model of Mac was ever actually bootable using the ROM alone, the 1991 Mac Classic model.) This architecture also helped to ensure that only Apple computers (and later licensed clones with the copyright-protected ROMs) could run Mac OS.

The Mac OS can be divided into two families of operating systems:

"Classic" Mac OS, the system which shipped with the first Macintosh in 1984 and its descendants, culminating with Mac OS 9
.
The newer Mac OS X
(the "X" is pronounced ten, as the Roman numeral). Mac OS X incorporates elements of OpenStep
(thus also BSD Unix and Mach) and Mac OS 9
. Its low-level BSD-based foundation, Darwin
, is free software/open source software.

"Classic" Mac OS (1984-2001)

The "classic" Mac OS is characterized by its total lack of a command line; it is a completely graphical operating system. Heralded for its ease of use, it is also criticized for its singletasking (in early versions) or cooperative multitasking (in later versions), very limited memory management, lack of protected memory, and susceptibility to conflicts among "extensions" that extend the operating system, providing additional functionality (such as networking) or support for a particular device. Some extensions may not work properly together, or work only when loaded in a particular order. Troubleshooting Mac OS extensions can be a time-consuming process of trial and error.

Mac OS originally used the Macintosh File System (MFS), a flat file system with only one kludged level of folders. This was replaced by the Hierarchical File System (HFS), which had a true directory tree. Both file systems are otherwise compatible.

[ Visit the complete Wikipedia entry for Mac OS ]

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