Classic Mac OS is a colloquial term used to describe a series of operating systems developed for the Macintosh family of personal computers by Apple Inc. The Macintosh operating system is credited with having popularized the graphical user interface concept. Apple released the original Macintosh on January 24, The first version of the system softwarewhich had no official name, was partially based on the Lisa OSpreviously released by Apple for the Lisa computer in The name Macintosh System Software came into use in with System 5.
Apple rebranded the system as Mac OS instarting officially with version 7. Initial versions of the System Software run one application at a time.
With the introduction of System 5, a cooperative multitasking extension called MultiFinder was added, which was later integrated into System 7 as part of the operating system along with support for virtual memory.
It retained most of the user interface design elements of the 68k macintosh software dating Mac OS, and there was some overlap of application frameworks for compatibility, but the two operating systems otherwise have completely different origins and architectures. The Macintosh project started in late with Jef Raskinwho envisioned an easy-to-use, low-cost computer for the average consumer.
In SeptemberRaskin began looking for an engineer who could put together a prototype. Bill Atkinsona member of the Apple Lisa team, introduced Raskin to Burrell Smitha service technician who had been hired earlier that year.
Apple's original concept for the Macintosh deliberately 68k macintosh software dating to minimize the user's conceptual awareness of the operating system.
Many basic tasks that had required more operating system knowledge on other systems could then be accomplished by mouse 68k macintosh software dating and graphic controls on a Macintosh.
This would differentiate it from its contemporaries such as MS-DOSwhich use a command-line interface consisting of tersely abbreviated textual commands. In JanuarySteve Jobs completely took over the Macintosh project. He was able to conserve precious ROM space by writing routines in assembly language code optimized with "hacks," or clever programming tricks.
The icons of the operating system, which represent folders and application softwarewere designed by Susan Karewho later designed the icons for Microsoft Windows 3. Apple was very aggressive in advertising their new 68k macintosh software dating. Apple was so successful in its marketing for the Macintosh that it quickly outsold its more sophisticated predecessor, the Lisa. Apple quickly developed a product named MacWorkswhich allowed the Lisa to emulate Macintosh system software through System 3, by which time it had been discontinued as the rebranded Macintosh XL.
Many of Lisa's operating system advances would not appear in the Macintosh operating system until System 7 or later. The initial purpose of this is to avoid using up the limited storage of floppy disks on system support, given that the early Macs have no hard disk only one model of Mac was ever actually bootable using the ROM alone, the Mac Classic model.
This architecture also allows for a completely graphical OS interface at the lowest level without the need for a text-only console or command-line mode: Several computer manufacturers over the years made Macintosh clones that were capable of running Mac OS.
These machines normally ran various versions of classic Mac OS. Steve Jobs ended the clone-licensing program after returning to Apple in Support for Macintosh clones was first exhibited in System 7. These changes were made to disassociate the operating system from Apple's own Macintosh models.
Both file systems are otherwise compatible. Files in most file systems used with DOSWindowsUnixor other operating systems have only one " fork ". The data fork contains the same sort of information as a file in other file systems, such as the text of a document or the bitmaps of an image file.
The resource fork contains other structured "68k macintosh software dating" such 68k macintosh software dating menu definitions, graphics, sounds, or code segments that would be incorporated into a program's file format on other systems. An executable file might consist only of resources including code segments with an empty data fork, while a data file might have only a data fork with no resource fork.
On the other hand, these forks would provide a challenge to interoperability with other operating systems. In copying or transferring a Mac OS file to a non-Mac system, the default implementations would simply strip the file of its resource fork. Most data files contained only nonessential information in their resource fork, such as window size and location, but program files would be inoperative without their resources.
This necessitated such encoding schemes as BinHex and MacBinarywhich allowed a user to encode a dual-forked file into a single stream, or inversely take a single stream so-encoded and reconstitute it into a dual-forked file usable by Mac OS. As part of Apple's goal of creating a computer with appliance-like simplicity, there is no explicit distinction made between the operating system software and the hardware it runs on.
Because of this, early versions of the operating system do not have a distinct name. The software consists of two user-visible files: The two files are contained in a folder directory labeled "System Folder", which contains other resource files, like a printer driverneeded to interact with the System.
These releases can only run one application at a 68k macintosh software dating, except for desk accessories, though special application shells such as Multi-Mac  or Switcher discussed under MultiFinder could work around this.
Visible changes are best reflected in the version number of the Finderwhere major leaps are found between 1. The software itself was still freely available through user groups and bulletin board services.
While the product box presented this update to the operating system as "version 5. Three of the four disks System Tools 1, System Tools 2 and Utilities 1 are all bootable, and the user could boot off of whichever floppy contained the tools the user needed. Because the disks were named System Tools, users and the press commonly referred to this version as "System Tools 5.
The primary new feature of System 5 is MultiFinderan extension which lets the system run several programs at once. The system uses a cooperative multitasking model, meaning that time was given to the background applications only when the running application yielded control. A change in system functions that applications were already calling to handle events makes many existing applications share time automatically, as well as be able to perform tasks in the background.
System Software 5 was available for a very short time and only in some countries, including the United States, Canada and some European countries. System Software 6 also referred to as "System 6" is a consolidation release of the 68k macintosh software dating system software, producing a complete, stable, and long-lasting operating system.
Two major hardware introductions requiring additional support under System 6 are the 68k macintosh software dating and 1.
Later, it would include support for the first specialized laptop features with the introduction of the Macintosh Portable. From System 6 "68k macintosh software dating," the Finder would have a unified version number closely matching that of the System, alleviating much of the confusion caused by the often considerable differences between earlier Systems.
On May 13,System 7 was released. It is a major upgrade over System 6, adding a significant user interface overhaul, new applications, stability improvements and many new features. Its introduction coincides with the release of and provided support for the Macintosh line. The System 7 era saw numerous changes in the Macintosh platform including a proliferation of Macintosh modelsthe 68k to Power Macintosh transition as well as the rise of Microsoft Windowsincreasing use of computer networking and the explosion in popularity of the Internet.
One of the most significant features of System 7 is virtual memory support, which previously had only been available as a third-party add-on. This change is known as being "bit clean". While System 7 itself is bit clean, many existing machines and thousands of applications were not, so it was some time before the process was completed.
To ease the transition, the "Memory" control panel contains switch to disable this feature, allowing for compatibility with older applications.
Another notable System 7 feature is built-in cooperative multitasking. In System Software 6, this function was optional through the MultiFinder.