System 7 (Macintosh)

From Free net encyclopedia

Template:Infobox OS System 7 (codenamed Big Bang) is a version of the Mac OS, the operating system of the Apple Macintosh computer. Various versions of System 7 were in widespread use from the early 1990s up until 1997, succeeding System Software 6. Features over System Software 6 included cooperative multitasking, virtual memory, personal file sharing, an improved user interface look, QuickTime, and QuickDraw 3D. It is still used by a small number of Macintosh users who own legacy Apple hardware of that era.

Apple released System 7.0 on May 13, 1991, which was also the first version of the Mac OS in which Apple dropped the term Software from the title. Note that "System 7" is often used as a generic term to refer to all 7.x versions. With the release of version 7.6 in 1997, Apple dropped the term System from the title as well, with the operating system being officially renamed as Mac OS.

1 Features
2 Software
3 Third-party software
4 Microsoft Windows Compatibility
5 Miscellaneous Information
6 Version History
7 Available Versions
8 See also
9 References
10 External links

[edit]

Features

Image:Macsys7.gif

Compared with System Software 6, System 7 offered:

Built-in co-operative multitasking. In System Software 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-based 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 ran 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, Hide/Show functionality was introduced, allowing the user to hide applications from view while still keeping them running.
Balloon Help, a widget-identification system similar to tooltips.
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 to") 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 outline fonts. Up to this point, all fonts on the Macintosh were bitmapped, or a set of bitmapped screen fonts paired with outline PostScript printer fonts; TrueType for the first time offered a single font format that looked great at any size on screen and on paper. This technology was recognized as being so important that a TrueType extension for System 6 was also released, along with an updated Font/DA Mover capable of installing these new kinds of fonts into the System 6 System file.
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 look 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 Software 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.

[edit]

Software

System 7 was the first version of the Mac OS that required a hard drive because a full installation was too large to fit on a 1.44 MB floppy disk. It 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, Power Pete, HyperCard and ClarisWorks. PowerPC Macintoshes included Graphing Calculator. System 7 also included networking and file sharing software in the form of system extensions and control panels.

The basic utilities installed by default with System 7 included SimpleText for basic text editing tasks and reading Readme documents. Also available on the additional "Disk Tools" floppy disk are Disk First Aid for disk repair and Apple HD SC Setup for initializing and partitioning disks.

Later versions of System 7, specifically System 7.5 and 7.6, came with a dedicated "Utilities" folder and "Apple Extras" folder including: AppleScript, Disk Copy, QuickDraw GX Extras and QuickTime Movie Player. More optional extras and utilities could be manually installed from the System Software disc.

[edit]

Third-party software

When Apple moved to the PowerPC processor, 68k applications were emulated on the new processor, while fat binaries allowed software to run natively on both 68k and PowerPC systems, similar to the Universal Binaries for the current PowerPC to Intel transition happening as of 2005. See also: Mac 68K emulator.

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 rendering technology was not available as a standard system feature until the introduction of QuickDraw 3D, many of the most innovative titles of the time were produced for System 7, using their own 3D engines.

[edit]

Microsoft Windows Compatibility

System 7.5 and up could access MS-DOS (FAT) formatted CDs and floppies with a control panel called PC Exchange, which was bundled freely with 7.5. Versions earlier than 7.5 could not access DOS disks, except for System 7.1 Pro, which included PC Exchange, AppleScript, and a few other extra features for an additional charge.

[edit]

Miscellaneous Information

At the time of its release, many users noticed that performance suffered as a result of upgrading from System Software 6 to System 7, though newer hardware soon made up for the speed differential. Another problem was System 7's large "memory footprint": System Software 6 could run on a single floppy disk and took up about 600 KB of RAM, whereas System 7 used well over a megabyte, and could no longer be usefully run from floppy-only machines. (Versions up to 7.5 could boot from a floppy, but there would be no room for other applications, although it was possible to access an AFP server on an AppleTalk network.) 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.

[edit]

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	OpenDoc	1995
7.5.1	March 1995
7.5.2	August 1995	Power Macintosh 7200
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	Power Macintosh 9500/200, Performa 6360
7.5.5	September 27th 1996
7.6	January 7th 1997
7.6.1	April 7th 1997

Soon after the initial release of System 7, the 7.0.1 minor update was released in October 1991. A patch called "System 7 Tune-Up" also followed, which fixed the "disappearing files" bug in which the system would lose files. See TidBITS #120 [1]. In August 1992, the 7.1 update was released which introduced the Fonts folder, allowing users to organize their fonts in the Finder, replacing the Font/DA Mover application used in System Software 6.

The first major upgrade was System 7.1.1, also known as System 7 Pro. This release was a bundle of 7.1 with AppleScript tools, QuickTime and Apple Open Collaboration Environment (AOCE). While System 7 had some trouble running in slightly older machines due to memory footprint, System 7 Pro barely fit into any Macintosh computers at the time. It was most commonly used for its minor bug fixes rather than its new functionality.

Apple joined the AIM alliance (Apple, IBM and Motorola) shortly after the release of System 7 in 1991, and started work on PowerPC-based machines that later became the Power Macintosh family. Support for these machines resulted in System 7.1.2.

System 7.1.2 for PowerPC Macs should not be confused with the last iteration of 7.1 for 68K Macs, called System 7.1.2P. This version added IDE drive support, and "Performa" features "Launcher," "Control Strip," and others that were later included with System 7.5. This is the last version of the Mac OS to ship with purely 68K code; later versions shipped "fat," with both 68K and PowerPC code in the binaries.

System 7.1.2 was never offered for retail sale; it shipped with the first batches of the 68LC040/68040-based 630 series (LC 630, Performa 630, Quadra 630) Macs. Later shipments of the 630 series shipped with System 7.5 instead.

The next major release was System 7.5, which included bug fixes from previous updates and added several new features including:

an updated startup screen featuring a progress bar
a new interactive help system called Apple Guide
a clock in the menu bar (based on the free "SuperClock" control panel by Steve Christensen)
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 playback of audio CDs, manage file sharing and printers and change the monitor resolution and color depth)
the Extensions Manager (enabling the user to turn extensions and control panels on and off; also based on a formerly third-party control panel)
PowerTalk, the predecessor to the Keychain system and also a system-level email handling service
the Launcher, a special Finder window containing shortcut buttons for frequently-used programs (in a manner somewhat akin to the Mac OS X Dock)
a hierarchal Apple menu (folders within the Apple Menu Items folder would expand into submenus showing their contents)
system-wide drag & drop for text and other data (selections could be simply dragged with the mouse and dropped to their new destination, bypassing the clipboard)
a scriptable Finder
Quickdraw GX, a 2-D graphics rendering and geometry engine
support for OpenDoc

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.

System 7.5.2, released only for the first PCI-based Power Macs, was notable for introducing Apple's new networking architecture, OpenTransport.

Minor versions followed up to System 7.5.5.

Mac OS 7.6 was the last major update, released in 1997. With 7.6, the operating system was officially called "Mac OS" instead of "System". Mac OS 7.6 introduced several features that were also included in Mac OS 8, including a revamped Extensions Manager, more native PowerPC code for Power Macs, more bundled Internet tools and utilities, and an overall more-stable Finder. In this version, the PowerTalk feature added in 7.5 was removed due to poor application support.

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 Mac 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.

[edit]

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.

Mac OS 7.5.3 and the 7.5.5 (US English) update can be downloaded for free: http://download.info.apple.com/Apple_Support_Area/Apple_Software_Updates/English-North_American/Macintosh/System/.

Other lauguages and English versions can be found at:http://download.info.apple.com/Apple_Support_Area/Apple_Software_Updates/.

[edit]

References

Harry McQuillen, 10 Minute Guide to System 7 (1991), ISBN 0672300338
Stuple, S.J., Macintosh System 7.5 For Dummies Quick Reference (1994), ISBN 1568849567
Bob Levitus, Macintosh System 7.5 for Dummies (November, 1994), ISBN 1568841973

[edit]