System 7 (Macintosh)

From Freepedia

This article may be too technical for most readers to understand. Please expand it to make it accessible to non-experts, without removing the technical details.


System 7
Image:System7screenshot.gif
Screenshot of System 7.5.3 Revision 2
Development team: Apple Computer
OS family: Classic Mac OS
Source model: Closed source
Latest stable release: 7.6.1 / April 7 1997
Kernel type: Monolithic
License: Proprietary
Working state: Historic, not supported
Website:

System 7 (codenamed "Big Bang") was a version of Mac OS, the operating system of the Apple Macintosh computer. System 7 was used in the early 1990s up until 1997, succeeding System 6. Features over System 6 included cooperative multitasking, virtual memory, personal file sharing, an improved user interface look, QuickTime, and QuickDraw 3D. It is still widely used by many Macintosh users who own Apple hardware of similar vintage. Apple released System 7.0 on May 13, 1991. Note that "System 7" is usually a generic term referring to all 7.x versions.

Contents

Features

Image:Macsys7.gif

Compared with System 6, System 7 offered:

  • Built-in co-operative multitasking. In System 6, this function was optional through the MultiFinder.
  • Trash was now a formal directory, allowing items to be preserved between reboots instead of being purged.
  • 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.
  • Aliases. 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 redirect to 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 an "Open" dialog box would open the original file. (Unlike the path-base approach of Microsoft Windows 95, aliases also store a reference to the file's catalog entry, so they continue work even if the file is moved or renamed. Aliases can be best described as a cross between a hard link and a symbolic link on UNIX-based systems, including Mac OS X.)
  • "System extensions" (small pieces of code that extended the system's functionality) were improved by relocating them to their own subfolder (rather than in the System folder itself as on earlier versions), and by allowing the user to hold down the shift key during bootup to disable them. Later versions of System 7 offered a feature called "Extensions Manager" which simplified the process of enabling/disabling individual extensions. Extensions were often a source of instability and these changes made them more manageable and assisted trouble-shooting.
  • The Control Panel Desk Accessory became the Control Panels folder (found in the System Folder, and accessible to the user from an alias in the Apple menu). The control panels themselves became separate files, stored within this directory.
  • 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 real multitasking was always enabled. The Desk Accessory technology was deprecated, with System 7 treating them largely the same as other applications. Desk Accessories now run in their own address space rather than borrowing that of a host application.
  • The Application menu, a list of running applications formerly at the bottom of the Apple menu under MultiFinder, became its own menu on the right. In addition, Unhide/Hide functionality was introduced, allowing the user to hide applications from view while still keeping them running.
  • AppleScript, a scripting language for automating tasks. While fairly complex for application programmers to implement support for it, this feature was powerful and popular with users, and a version of it 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 Mac OS for fast on-screen drawing.
  • 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.
  • TrueType was integrated into the operating system. Although it was initially available as an INIT for System 6.0.7, this change essentially guaranteed widespread availability of the technology.
  • A new full-color user interface. Although this feature made for a visually appealing interface, it was optional. On machines not capable of displaying color, or those with their display preferences set to monochrome, the interface defaulted back to the black-and-white of previous versions. Only some widgets were colorized — scrollbars, for instance, had a new look, but buttons remained in black-and-white.
  • A new Sound Manager API, version 3.0, replaced the older ad hoc APIs. The new APIs featured significantly improved hardware abstraction, as well as higher-quality playback. Although technically not a new feature for System 7 (these features were available for System 6.0.7), Sound Manager 3.0 was the first widespread implementation of this technology to make it to most Mac users.
  • System 7 paved the way for a full 32-bit address space, from the previous 24-bit address space. 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. To ease the transition, the "Memory" control panel contained a switch to disable this feature, allowing for compatibility with older applications.

Software

System Requirements

System 7.0 requires an Apple Macintosh computer with at least 2 megabytes of RAM and a hard drive for installation, with a Motorola 68030 microprocessor or equivalent required to use virtual memory.

Bundled

System 7 did not come bundled with major software packages itself, but newly purchased Apple Macintosh computers often included bundled software such as Millie's Math House, HyperCard and ClarisWorks. PowerPC Macintoshes included Graphing Calculator, previously not available for System 6. System 7 also included networking and file sharing software in the form of system extensions and control panels.

Utilities

The basic utilities that came as default with a System 7 installation included SimpleText for basic text editing tasks and reading Readme documents. Also additionally available on an additional "Disk Tools" floppy disk are Disk First Aid for disk optimization and repairing tasks and Apple HD SC Setup for initializing and partitioning disks.

Later versions of System 7, specifically System 7.5 and 7.6, come with a dedicated "Utilities" folder and "Apple Extras" folder including: AppleScript, Disk Copy, QuickDraw GX Extras and QuickTime Movie Player. More extras and utilities are available on the System Software disc to optionally install manually.

3rd party software

Image:Themacdisk.jpg
Before System 7 the amount of Macintosh software was limited compared to the amount of 3rd party software available for Microsoft Windows. With the release of System 7 many shareware developers began to develop their own extensions and applications which were distributed through user groups and magazine disks (and later the Internet.) Developers created thousands of new programs for System 7 every year, many released under the shareware scheme.

When Apple transistioned to the PowerPC processor, 68k applications were emulated on the new processor, while FAT binaries allowed software to run on both 68k and PowerPC systems, similar to the Universal_Binaries for the current PowerPC to Intel transition happening as of 2005.

With support for color displays, shareware developers also started to develop more realistic arcade games for the Macintosh such as pac-man clones and later first-person shooters such as Tomb Raider and Marathon. Although 3D technology was not available until the introduction of QuickDraw3D, many of the time's most innovative titles were produced for System 7.

Windows Compatibility

System 7 improved compatibility with Windows, enabling easier access of files created under Microsoft Windows. System 7 was capable of automatically reading MS DOS disks without reformatting; the disks simply mounted to the desktop like a "normal" Mac disk would. System 7's included text editor, SimpleText was also capable of reading plain text files created on a DOS or Microsoft Windows computer.

Miscellaneous Info

At the time of its release, many users noticed that performance suffered as a result of upgrading from System 6 to System 7, though newer hardware soon made up for the speed differential. Another problem was System 7's large "memory footprint": System 6 could run on a single floppy disk and took up about 600KB of RAM, whereas System 7 used well over a megabyte and could no longer be usefully 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. Offsetting this was the inclusion of a hard disk as standard in most Mac models; only the long-lived Mac Plus did not ship with one.

System 7.0 was adopted quite rapidly by Mac users, and quickly became one of 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.

The engineering group within Apple responsible for System 7 came to be known as the "Blue Meanies", named 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.

Version History

Version Number Release Date Computer
7.0 Early 1991
7.0.1 October 1991 Macintosh Quadra 700/900, PowerBook 100/140/170
7.0.1P March 1992 Macintosh 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 Power Macintosh 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 Macintosh 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 an application called Font/DA Mover.

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 Power Macintosh series. Support for these machines resulted in System 7.1.2, which also included a number of fixes and new features. 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 many features:

  • An updated startup sceen, featuring a progress bar.
  • A new interactive help system called Apple Guide. Apple Guide was extremely powerful, but tedious to implement. Correspondingly, few programs made use of it's features.
  • A clock in the menu bar (originally the shareware control panel "SuperClock!").
  • An Apple menu item called Stickies (formerly a third-party application called "PasteIt Notes") which provided virtual Post-It Notes.
  • WindowShade, another former shareware control panel which provided the ability to condense a window down to its title bar.
  • The Control Strip, a fast way to change the system volume, control the Apple Audio CD player, manage file sharing and printers, change the monitor resolution and color depth, etc. Many custom modules were made for the Control Strip by third-party developers.
  • The Extensions Manager, another shareware control panel, which enabled the user to turn other extensions and control panels on and off.
  • PowerTalk, the predecessor to Mac OS X's Keychain system and also a system-level system for handling email. Poor application support at the time led to PowerTalk being removed by Mac OS 7.6.

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, named Copland. When the Copland project was abandoned in 1996, Apple announced plans to release an OS update every six months until Rhapsody (which would later evolve into OS X) 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.

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 descriptive .txt file.

See also

External links


History of the Macintosh Operating System
Classic Mac OS: System 6 | System 7 | Mac OS 8 | Mac OS 9
Mac OS X: v10.0 (Cheetah) | v10.1 (Puma) | v10.2 "Jaguar" | v10.3 "Panther" | v10.4 "Tiger" | v10.5 "Leopard"
Mac OS X Server
Retrieved from "http://en.freepedia.org/System_7_%28Macintosh%29.html"


Views
Personal tools
In other languages
Similar Links