System 7 (Macintosh)

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Template:Infobox OS

System 7 was a version of Mac OS, the operating system of the Apple Macintosh computer, which was used in the early 1990s up until 1997, as the successor to System 6. It featured built-in cooperative multitasking, virtual memory, personal file sharing, a slightly 3-D looking interface taking advantage of colors, QuickTime for video clips capture and playback, QuickDraw 3D with standard file format for 3D data, and it is still widely used by many Macintosh users who own Apple hardware of similar vintage. The "System 7" term is used to describe all the 7.x versions. The codename used for System 7 was "Big Bang", which reflects the considerable changes that came with it. System 7.0 was released on May 13th, 1991. It offered a number of system enhancements that were either previously not available, or were optional extensions to the operating system.



Missing image
Macintosh System 7 boxes

Compared with System 6, System 7 offered:

  • Trash was now a real folder instead of the special status it previously had. This allowed items to be put in the trash on different volumes, each one having its own Trash.
  • Personal File Sharing. Along with various UI improvements for AppleTalk setup, System 7 also included a basic file sharing server allowing any machine to publish folders to the AppleTalk network.
  • The Control Panel Desk Accessory became the Control Panel folder (found in the System Folder, accessible to the user from an alias in the Apple menu), including small applications separate to each other such as "Colors" , "Labels" and "Desktop Patterns".
  • In a later version of System 7 the "Control Strip" was introduced, adding a way to change the system volume, control the Apple Audio CD player, manage file sharing and printers, and change the monitor resolution and color depth as well as other attributes to system software and hardware. Custom modules could be made for the Control Strip by 3rd party developers
  • System "extensions" (small pieces of code that extended the system's functionality) were also improved by placing them in their own subfolder (rather than in the System folder itself as on earlier versions), and holding down the shift key during bootup would disable them. Extensions were often a source of instability and this change helped make them more manageable and assisted trouble-shooting. In System 7.5 the Extension Manager was introduced to provide an easier way to manage extensions and control panels.
  • In System 7 and later, an alias is a small file that represents another object in the file system. A typical alias is small, between 1 and 5 KB. It acts as a stand-in for any object in the file system, such as a document, an application, a folder, a hard disk, a network share or removable medium or a printer. When double-clicked, the computer will act the same way as if the original file had been double-clicked. Likewise, choosing an alias file from within a 'File Open' dialog box would open the original file. Under Microsoft Windows Aliases are known as Shortcuts.
  • The Apple menu (previously home only to Desk Accessories pulled from DRVR resources in the System file) now listed the contents of a folder ("Apple Menu Items"), including aliases. Desk Accessories had originally been intended to provide a form of multitasking and were no longer necessary now that multitasking was always enabled. The desk accessory technology was deprecated, with System 7 treating them largely the same as other applications. DAs were now all run by default in their own partition (address space) rather than borrowing the host application's.
  • The Application menu, a list of running applications formerly at the bottom of the Apple menu under MultiFinder, was moved to its own menu on the right, along with Hide and Unhide functionality.
  • AppleScript. This was an entire architecture for making scriptable applications. While fairly complex for programmers to implement, this feature was powerful and popular with users, and is still available to this day as part of Mac OS X.
  • AppleEvents. Supporting AppleScript was a new model for "high-level" events to be sent into applications, along with support to allow this to take place over the AppleTalk network.
  • 32-bit QuickDraw, supporting so-called "true color" imaging was included as standard; it was previously available as a system extension. QuickDraw was used in system 7 for fast on-screen drawing capabilities.
  • Publish and Subscribe. This feature permitted data "published" by one application to be imported ("subscribed") by another, and the data could be updated dynamically. Programmers complained that the API was unwieldy, and relatively few applications ended up adopting it.
  • Balloon help provided on-screen tooltips. A Help menu was added to the menu bar to control it, and to provide a standard place for help-related commands, which previously had been found in a variety of places according to developers' whims.
  • TrueType, a new outline font technology developed by Apple.
  • A new full-color user interface was included which gave a neat color appearance on color machines but which gracefully dropped back to the standard black and white interface on machines not supporting color. Strangely, only some widgets were colorized -- scrollbars, for instance, had a new look, but buttons remained in black-and-white.
  • A new Sound Manager API which replaced the older ad-hoc APIs that did not abstract the hardware to any great degree. This had also been included in the last version of System 6, 6.0.8.
  • System 7 started to pave the way to move to a full 32-bit address space, from the previous 24-bit address space, which limited memory to a maximum of 8MB. This process involved making all of the routines in OS code use the full 32-bits of a pointer as an address - prior systems used the upper bits as flags. This change was known as being "32-bit clean". While System 7 itself was 32-bit clean, many existing machines and thousands of applications were not, so it was some time before the process was completed.

Other Changes

There were also a large number of architectural changes to make the OS more coherent and stable. Apple boasted on its release that System 7 was "rock solid", and while it was a great improvement over the earlier systems, the claim was rather hyperbolic. This became somewhat empty over the following years, as stability of the system degraded terribly as the complexity of the systems grew. Later versions of 7 were notoriously unreliable, often freezing the entire machine after benign application errors.

Many also felt that performance suffered as a result of upgrading from System 6 to System 7, though new hardware soon made up for the speed loss. Another problem was System 7's large "memory footprint"; System 6 would run on a single floppy and took up about 600k of RAM, System 7 used well over a megabyte and could no longer be run from floppy-only machines (it could boot from a floppy, but there would be no room for other applications). It was some time before the average Mac shipped with enough RAM built-in for System 7 to be truly comfortable.

System 7.0 was adopted quite rapidly by Mac users, and quickly became the base requirements for new software. Until the advent of OS X, System 7 was by far the largest shake-up and revamp of the Mac OS since its inception. Unlike the transition to OS X, the System 7 transition from System 6 was fairly smooth, largely transparent (meaning new features were implemented elegantly, and the look and feel was mostly unchanged), and widely adopted as the standard Macintosh operating system. Mac OS 8 and Mac OS 9 were relatively minor upgrades from System 7.x, compared to the changes from 6.x to 7.0.

The coding group within Apple responsible for System 7 were known as the "blue meanies" after the blue index cards on which were written the features that could be implemented in a relatively short time. In comparison, the pink index card features were handled by the Pink group, later becoming the ill-fated Taligent project. Despite the idea of System 7 being the "quick win", it was still delivered several years late.

Version History

Version Number Release Date Computer
7.0 Early 1991
7.0.1 October 1991 Quadra 700/900, PowerBook 100/140/170
7.0.1P March 1992 Performa 400, 575
7.1 August 1992
7.1P Early 1993
7.1.1 (Pro) October
7.1.1 October 1993 PowerBook Duo 250/270, PowerBook 520
7.1.2 March 1994 PowerMac 6100/7100/8100
7.1.2P July 1994 Quadra 630
7.5 1995
7.5.1 March 1995
7.5.2 August 1995
7.5.3 January 1996
7.5.3 Revision 2 May 1st 1996
7.5.3 Revision 2.1 August 7th 1996 Performa 6400
7.5.3 Revision 2.2 August 7th 1996 PowerMac 9500/200, Performa 6360
7.5.5 September 27th 1996
7.6 January 7th 1997
7.6.1 April 7th 1997

System 7.0.1 and 7.1

Soon after the release of 7.0, System 7.0.1 was released with a number of fixes. A patch, called "System 7 Tune-Up" fixed the infamous "disappearing files" bug in early versions of System 7, in which the system would lose files. (See TidBITS #120, [[1] (])

Next year's System 7.1 introduced the new Fonts folder, allowing users to organize their fonts in the Finder, this was previously done in System 6 with a desktop accessory.

System 7 Pro

The first major upgrade was System 7.1.1, also known as System 7 Pro. This release was basically a bundle of 7.1 with AppleScript tools, QuickTime and Apple Open Collaboration Environment (AOCE). While System 7 had troubles running in slightly older machines due to memory footprint, System 7 Pro would barely fit into even the most "loaded" machines of the era. Most users installed it for various minor fixes, ignoring the new functionality.

System 7.1.2

Soon after the release of System 7, Apple joined the AIM alliance and started work on PowerPC-based machines that would later become the PowerMacs. Support for these machines resulted in System 7.1.2, which included a number of fixes and new features as well. This was followed quite quickly with System 7.1.3, primarily a bug-fix release.

System 7.5

The next major release was System 7.5, which rolled up all the fixes from previous versions and added a progress bar during startup and the new Apple Guide help system. Apple Guide was extremely powerful, but tedious to implement due to its power, and few programs supported it. System 7.5 also incorporated a number of system enhancements that were previously available as shareware for the Mac including a clock in the menu bar (taken from SuperClock!), Stickies (formerly PasteIt Notes) and WindowShade (the ability to condense a window down to its title bar). System 7.5.1 was primarily a bug fix on 7.5, but also introduced a new "Mac OS" startup screen in preparation for Mac clones. Minor versions followed up to System 7.5.5.

Through this period Apple had been attempting to release a completely new "modern" operating system, Copland. When the Copland project was finally killed in 1996, they announced plans to release an OS update every six months until Rhapsody shipped. Two more releases were shipped, now officially branded as the "Mac OS" - Mac OS 7.6, and the minor bug fix 7.6.1. Future versions were released as Mac OS 8 and Mac OS 9, although some question whether the differences in these ugprades were substantial enough to warrant the large version number changes.

Available Versions

Apple created and published an "Older Software Downloads" webpage on their AppleCare Support website on July 17, 2001. Since then diskette images to install System 7.0, System 7.0.1, and System 7.5.3 as well as the System 7.5.5 Update have been available as free downloads for legacy Macintosh users and those who want to emulate the older Mac OS. In addition to System 7 related downloads are also At Ease downloads and Mac OS 8 updates. All of the diskette image files are in MacBinary format and are accompanied by a description .txt file.

See Also

External Links

Template:Mac OS Historyit:System 7 fr:Système 7


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