Mac OSMac OS, which stands for Macintosh Operating System, is Apple Computer's operating system for Apple Macintosh computers. Mac OS was the first commercially successful operating system which used a graphical user interface. The Macintosh team included Bill Atkinson, Jef Raskin and Andy Hertzfeld. There are a variety of views on how the Macintosh was developed and where the underlying ideas originated. While the connection between the Macintosh and the Alto project at Xerox PARC has been established in the historical record, the earlier contributions of Ivan Sutherland's Sketchpad and Doug Engelbart's On-Line System are no less significant. See History of the GUI, and Apple v. Microsoft. Apple deliberately played down the existence of the operating system in the early years of the Mac to help make the machine appear more user-friendly and to distance it from other systems such as MS-DOS, which were portrayed as arcane and technically challenging. Apple wanted Mac to be portrayed as a system that would "just work" when you turned it on.
Classic Mac OSThe "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 cooperative multitasking, almost total lack of memory management, and susceptibility to extension conflicts. "Extensions" are program modules that extend the operating system, providing additional functionality (such as networking) or support for a particular device. Some extensions are prone not to work properly together or only when loaded in a particular order. Troubleshooting Mac OS extensions can be a time-consuming process of trial and error. Mac OS also introduced HFS, a innovative new type of filesystem. Whereas a file on DOS or Unix would simply be a sequence of bytes, requiring an application to know which bytes represented code and which were graphic or other data, Mac files had two different "forks." In addition to the data fork, which contained a sequence of bytes, there was a resource fork which contained structured data such as menu definitions, graphics, sounds, or code segments. An application file might consist only of resources with no data fork. A text file might contain its text in the data fork and styling information in its resources, so that an application which didn't recognize the styling information could still read the raw text. Despite the many assets of this arrangement, it became quite a challenge to interoperate with other operating systems which did not recognize such a system; for example, copying a file from a Mac to DOS or Unix would strip it of its resource fork. By the late 1990s, it was clear the useful life of this 1980s-era technology was coming to an end, with other more stable multitasking operating systems being developed.Mac OS XMac OS X brought Unix-style memory management and pre-emptive multitasking to the Mac platform. Vastly improved memory management allowed more programs to run at once and virtually eliminated the possibility of one program crashing another. It is also the first Mac OS to include a command line, although it is never seen unless the user launches a "terminal" program. However, since these new features put higher demands on system resources, Mac OS X is only officially supported on PowerPC G3 and newer processors. Even then, it runs slowly on older G3 systems for many purposes. Mac OS X has a compatibility layer for running older Mac applications, the Classic Environment (known to programmers as "the blue box"). This runs a full copy of the older Mac OS 9.x as a Mac OS X process. Most well-written "classic" applications function properly under this environment, but compatibility is only assured if the software was written to be unaware of the actual hardware, and to interact solely with the operating system.Mac OS technologies\n* QuickDraw: the imaging model which first provided mass-market WYSIWYG\n* Finder: the interface for browsing the filesystem and launching applications\n* MultiFinder: the first version to support simultaneously running multiple apps\n* Chooser: tool for accessing network resources (e.g., enabling AppleTalk)\n* ColorSync: technology for ensuring appropriate color matching\n* Mac OS memory management: how the Mac managed RAM and virtual memory before the switch to UNIX\n* PowerPC emulation of Motorola 68000: how the Mac handled the architectural transition from CISC to RISC (see Mac 68K emulator)\n* Desk Accessories: small "helper" apps that could be run concurrently with any other app, prior to the advent of MultiFinder or System 7.\n* PlainTalk: speech synthesis and speech recognition technology\n* Mac-Roman : Character setProject Star TrekOne interesting historical aspect of the classic Mac OS was a relatively unknown secret prototype Apple started work on in 1992, code-named Project Star Trek. The goal of this project was to create a version of Mac OS that would run on Intel-compatible x86 personal computers. It was short lived, being cancelled only one year later in 1993 due to political infighting, though its team was able to get the Macintosh Finder running smoothly on a PC. Although the Star Trek software was never released, third-party Macintosh emulators, such as vMac, Basilisk II, and Executor eventually made it possible to run the classic Mac OS on x86 PCs.See also
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"The mistakes are all waiting to be made." - chessmaster Savielly Grigorievitch Tartakower (1887-1956) on the game's opening position |
