View source for System 7

{{short description|Seventh major release of the classic Mac OS (1991)}}
{{Use mdy dates|date=December 2023}}
{{Multiple issues|{{More citations needed|date=December 2023}}
{{Original research|date=December 2023}}}}
{{About|the seventh major release of the classic Apple Macintosh operating system||}}
{{Infobox OS|
| name = System 7/MacOS 7
| logo = 
| family = [[Macintosh operating systems|Macintosh]]
| screenshot = Mac_OS_7.6.1_emulated_inside_of_SheepShaver.png
| caption = The Mac OS 7.6.1 desktop
| version of = [[classic Mac OS]]
| developer = [[Apple Computer]]
| source_model = [[Closed source]]
| released = {{Start date and age|1991|05|13}}
| latest_release_version = 7.6.1
| latest_release_date = {{Start date and age|1997|04|07}}
| preceded_by = [[System 6]]
| succeeded_by = [[Mac OS 8]]
| supported platforms = [[Motorola 68000 series|Motorola 68k series]], [[PowerPC]] (since 7.1.2)
| kernel_type = [[Monolithic kernel|Monolithic]] (68k),<br>[[nanokernel]] (PowerPC)
| license = [[Proprietary software|Proprietary]]
| working_state = Historic
| tagline = It's powerful, it's easy to use-it's the new operating system for your Macintosh.
| support_status = Historical, unsupported as of May 2001
| website = {{webarchive |url=https://web.archive.org/web/19970412143953id_/http://macos.apple.com:80/macos/releases.html |date=April 12, 1997 |title=Mac OS Releases}}
}}
{{classic Mac OS sidebar}}
'''System 7''' (later named '''Mac OS 7''') is the seventh major release of the [[classic Mac OS]] [[operating system]] for [[Mac (computer)|Macintosh]] computers, made by [[Apple Inc.|Apple Computer]]. It was launched on May 13, 1991, to succeed [[System 6]] with [[virtual memory]], personal [[file sharing]], [[QuickTime]], [[TrueType]] fonts, the [[Force Quit]] dialog, and an improved user interface.<ref>{{cite book |last1=Norton |first1=Peter |title=Inside System 7 |date=1992 |publisher=Brady Publishing |isbn=0-13-656273-6 |pages=215 |edition=1st |url=https://archive.org/details/insidesystem70000nort |access-date=3 March 2024}}</ref><ref>{{cite book |last1=Danuloff |first1=Craig |title=The System 7 Book |date=April 6, 1991 |publisher=Ventana Press, Inc |isbn=0-940087-58-8 |edition=4th |url=https://archive.org/details/mac_The_System_7_Book_1991 |access-date=3 March 2024}}</ref>

It was [[codename|code-name]]d "Big Bang" in development and the initial release was named "The System" or "System" like all earlier versions. With version 7.5.1, the name "Mac OS" debuted on the boot screen, and the operating system was officially renamed to Mac OS in 1997 with version 7.6. The Mac OS 7 line was the longest-lasting major version of the Classic Mac OSes due to the [[Development hell|troubled development]] of [[Copland (operating system)|Copland]], an operating system intended to be the successor to OS 7 before its cancellation and replacement with [[Mac OS 8]].

==Development==
[[File:Secret_About_Box_from_System_7.0.png|right|thumb|The Secret About Box debuted as an [[Easter egg (media)|Easter egg]] in System 7.0, with the [[Blue Meanies (Apple Computer)|Blue Meanies]] credits.]]
{{details|Blue Meanies (Apple Computer)|Taligent}}
{{anchor|Pink and Blue}}
By 1988, the Macintosh had been on the market for four years. Some aspects of the operating system were beginning to fall behind those of [[Microsoft Windows]].<ref name="Apple: The Inside Story">{{cite book |title=Apple: The Inside Story of Intrigue, Egomania and Business Blunders |first=Jim |last=Carlton |orig-year=1997 |date=1999 |isbn=978-0099270737 |oclc=925000937 |type=hardback |edition=2nd |publisher=Random House Business Books |location=London | url=https://archive.org/details/appleinsidestory00carl | via=[[Internet Archive]] | access-date=March 3, 2024}}</ref>{{rp|133}} Many of the assumptions of the System software architecture were obsolete – mainly, the single-tasking model, the replacement of which had first been examined in 1986's Switcher and then replaced with [[MultiFinder]] in [[Classic Mac OS#System Software 5|System 5]].

In March 1988,{{efn|name="n1"}}<ref name="Taligent's Guide">{{cite book |title=Taligent's Guide to Designing Programs: Well-Mannered Object-Oriented Design in C++ |series=Taligent Reference Library |first=David |last=Goldsmith |publisher=Addison-Wesley |location=Reading, MA |date=June 1994 |isbn=978-0201408881 |oclc=636884338}}</ref>{{rp|XXIII-XXIV}} shortly before the release of System 6, a group of senior technical staff and managers at Apple held an offsite meeting to plan the future course of Mac OS development.<ref name="Apple: The Inside Story"/>{{rp|96}} Improvements that seemed achievable in the short term were written on blue [[index card]]s, longer-term goals like true multitasking on pink cards, and more ambitious ideas like an [[Object-oriented programming|object-oriented]] [[file system]] on red cards.<ref name="Apple: The Inside Story"/>{{rp|96-98}}<ref name="Singh, pg. 2">Singh, pg. 2</ref> The blue and pink ideas proceeded in parallel teams. The Blue team nicknamed itself [[Blue Meanies (Apple Computer)|Blue Meanies]], after characters in the film ''[[Yellow Submarine (film)|Yellow Submarine]]'', and released System 7 in 1991.<ref name="bluemeanieseastereggs">{{cite web | url=https://www.mackido.com/EasterEggs/BlueMeanies.html | title=Apple Easter Eggs | publisher=MacKiDo | date=August 26, 1998 | accessdate=March 18, 2024 | first1=David K. | last1=Every | first2=Daniel | last2=Fanton}}</ref><ref name="Apple: The Inside Story"/>{{rp|169}} Pink was spun off into [[Taligent, Inc]] in 1992 within the [[AIM alliance]] with [[IBM]].<ref name="Apple: The Inside Story"/>{{rp|167}}

==Overview==
===Changes===
As intended with the Blue and Pink model, improvements in System 7 are significant but incremental.

* A new Sound Manager [[API]], version 2.0, replaces the older ''[[ad hoc]]'' APIs. The new APIs provided significantly improved [[hardware abstraction]] and higher-quality playback.
* 32-bit [[QuickDraw]], supporting so-called "true color" imaging, is standard; it was previously available as a system extension.
* System 7 allows a 32-bit program address space.  This expanded the memory addressing capabilities from the previous 24-bit address space and increased the system memory limit from 8MB to 4GB.<ref>{{Cite web |date=August 7, 1989 |title=InfoWorld Aug 7, 1989 |url=https://books.google.com/books?id=vDAEAAAAMBAJ&pg=PT69 |url-status=live |archive-url=https://web.archive.org/web/20210602232344/https://books.google.com/books?id=vDAEAAAAMBAJ&pg=PT69 |archive-date=June 2, 2021 |access-date=May 26, 2015}}</ref>
* System 7 makes MultiFinder's [[cooperative multitasking]] mandatory.
* Trash became a normal directory allowing items to be preserved between reboots and disk eject events instead of being purged.
* [[Extension (Mac OS)|System extension]]s are relocated to their own subfolder rather than in the root level of the [[System folder|System Folder]] as in System 6. They can be installed or removed simply by moving these "extensions" to or from the folder and then rebooting the computer. 
* Similarly, the [[Control panel (Mac OS)|Control Panel]] [[desk accessory]] becomes the Control Panels folder. The control panels themselves are separate files stored within this directory.
* Under System 6, the Apple Menu contains both a list of desk accessories and a list of running programs under MultiFinder. In System 7 the list of active programs is relocated to its own Application Menu.
* System 7.1 introduces System Enablers, small extensions that are loaded at startup to support Macintosh models introduced since the last OS revision.<ref>{{Cite web |date=February 18, 2012 |title=System 7.1 through Mac OS 7.6: Compatibility With Macintosh Computers |url=https://support.apple.com/kb/TA47341?locale=en_US&viewlocale=en_US |url-status=live |archive-url=https://web.archive.org/web/20211219222009/https://support.apple.com/kb/TA47341?locale=en_US&viewlocale=en_US |archive-date=December 19, 2021 |access-date=February 9, 2022 |website=support.apple.com}}</ref>
*Cannot run on [[Macintosh 512Ke]].

===New features===
* Personal [[File Sharing]] – along with [[user interface]] improvements for [[AppleTalk]], System 7 includes a basic file-sharing server allowing any machine to publish folders to the AppleTalk network.
* [[Alias (Mac OS)|Aliases]] – small files that represent another object in the [[file system]]. Similar in concept to [[Unix]] [[symbolic link]]s and [[shortcut (computing)#Microsoft Windows|Windows shortcuts]], an alias in System 7 acts as a redirect to any object in the file system, such as a [[document]], an [[Application software|application]], a [[folder (computing)|folder]], a [[hard disk]], a [[network share]] or removable medium or a [[Printer (computing)|printer]]. 
* [[Drag and drop]] – document icons can be dragged with the mouse and "dropped" onto application icons to open in the targeted application. System 7.5's Drag Manager expanded the concept system-wide to include multiple data types such as text or audio data.
* ''Stationery'', allowing users to save often-used document styles as a [[template (file format)|template]]. "Stationery-aware" applications create a new, untitled file containing the template data.
*[[Balloon Help]], a widget-identification system similar to [[tooltip]]s.
* [[AppleScript]], a [[scripting language]] for automating tasks. 
* [[AppleEvents]], a new [[interprocess communication]] model for "high-level" events to be sent to applications including support for AppleEvents over an AppleTalk network.
* [[Publish and Subscribe (Mac OS)|Publish and Subscribe]] permits information "published" by one application to be "subscribed" to in a document of another application, so that it is automatically updated if the original is changed.
* [[TrueType]] outline fonts, replacing bitmapped fonts and outline [[PostScript]] printer fonts. TrueType for the first time offers a single font format that scales to any size on screen and on paper.
* A newly colorized [[user interface]], for machines that support color.

===Installation===
After initial publication on a set of 15 floppy disks, System 7 became the first Apple operating system to be released on a [[compact disc]]. Unlike earlier systems, System 7 did not come bundled with major software packages. Newly purchased [[Mac (computer)|Macintosh]] computers had System 7 installed and were often bundled with software such as [[HyperCard]], [[At Ease]] and ''[[Mouse Practice]]''. Later, the [[Macintosh Performa]] family added various [[software bundles]] including [[ClarisWorks]], [[The New Grolier Multimedia Encyclopedia]], [[Microsoft Bookshelf]], ''[[Spectre VR]]'' and ''[[Power Pete]]''. Since System 7 was introduced before the Internet came to popular usage, software such as [[MacTCP]], [[FreePPP]], and [[Netscape]] were not included.  They later became available on disk from [[Internet service provider]]s and bundled with books such as [[Adam C. Engst]]'s Internet Starter Kit for Macintosh. [[Power Macintosh]] machines also included [[NuCalc]], a graphing calculator. System 7 includes [[AppleTalk]] networking and file-sharing software in the form of system extensions and control panels.

The basic utilities installed by default with System 7 include [[TeachText]] (which was replaced by [[SimpleText]] in later versions) for basic text editing tasks and reading [[README|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 Mac OS 7.6, come with dedicated "Utilities" and "Apple Extras" folders including: [[AppleScript]], [[Apple Disk Copy|Disk Copy]], [[QuickDraw GX]] Extras and [[QuickTime]] Movie Player. More optional extras and utilities can be manually installed from the System CD.

===Transition to PowerPC===
System 7.1.2 is the first version of the Macintosh System Software to support Apple's new [[PowerPC]]-based computers. 68k applications that had not yet been updated to run natively on these systems were [[Emulator|emulated]] transparently (without the user having to intervene) by a built-in [[Mac 68k emulator|68k processor emulator]]. [[Fat binary|Fat binaries]], which contained the code necessary to run natively on both PowerPC and 68k systems, became common during this time. This process was similar to the distribution of [[Universal binary|universal binaries]] during the [[Mac transition to Intel processors]] in 2006, as well as the [[Mac transition to Apple silicon]] beginning in 2020.

System 7.1.2 is the only release of the Macintosh operating system that boots stating "Welcome to Power Macintosh." Release 7.1.2P reverts this.<ref>{{Cite web |date=March 14, 1994 |title=InfoWorld |url=https://books.google.com/books?id=BjsEAAAAMBAJ&dq=%22welcome+to+power+macintosh%22&pg=PA98 |url-status=live |archive-url=https://web.archive.org/web/20220915131107/https://books.google.com/books?id=BjsEAAAAMBAJ&dq=%22welcome+to+power+macintosh%22&pg=PA98 |archive-date=September 15, 2022 |access-date=January 26, 2022}}</ref>

===PC compatibility===
System 7.0 and 7.1 have a utility called [[Apple File Exchange]], which accesses the contents of [[File Allocation Table|FAT]]- and [[Apple II]]-formatted floppy disks. Since System 7 Pro, [[PC Exchange]] is included, which allows the system to mount FAT-formatted [[floppy disk]]s on the desktop like Macintosh disks. [[OS/2]] disks can use the FAT file system. Macs can read and write UNIX file systems using extra software. System 7 accesses PC networks and uses TCP/IP and other compatible networking stacks.

===Miscellaneous===
System 7 had a larger memory footprint than System 6. System 6 could boot the system from a single 800k [[floppy disk]] and uses about {{nowrap|600 [[kilobyte|KB]]}} of [[Random-access memory|RAM]], whereas System 7 used well over one [[megabyte]]. It was some time before the average Mac shipped with enough RAM built-in for System 7 to be truly comfortable. System 7 was the first system release that could no longer be usefully run on floppy-only systems. Although most Macintosh models sold at the time included a hard disk as standard equipment, owners of older models were required to upgrade their hardware by buying either a new Mac or an external [[SCSI]] hard disk drive if they wished to run System 7.

The official system documentation, ''[[Inside Macintosh]]'', initially shipped in three volumes, with another added to describe the changes introduced with the [[Mac Plus]],<ref>[https://www.amazon.com/Inside-Macintosh-Volume-Apple-Computer/dp/0201054094 "Inside Macintosh, Volume 4"] {{Webarchive|url=https://web.archive.org/web/20160305023842/http://www.amazon.com/Inside-Macintosh-Volume-Apple-Computer/dp/0201054094 |date=March 5, 2016 }}, Amazon</ref> and another for the [[Mac II]] and [[Mac SE]].<ref>{{Cite web |title=Book Collection |url=http://school.anhb.uwa.edu.au/personalpages/kwessen/web/books/Books.html |url-status=live |archive-url=https://web.archive.org/web/20121124070714/http://school.anhb.uwa.edu.au/personalpages/kwessen/web/books/Books.html |archive-date=November 24, 2012 |access-date=December 19, 2012}}</ref>

System 7's virtual memory requires a Macintosh with a paged [[memory management unit]] (PMMU). The [[Motorola 68030]] CPU has one, or one can be added to a 68020-equipped [[Macintosh II]].

System 7.0 was adopted quite rapidly by Mac users and quickly became one of the base requirements for new software.

The engineering group within Apple responsible for System 7 came to be known as the "[[Blue Meanies (Apple Computer)|Blue Meanies]]", named after the blue [[index card]]s on which were written the features that could be implemented in a relatively short time as part of Apple's operating system strategy. 

The pink index card features were handled by the Pink group, later becoming the ill-fated [[Taligent]] project.<ref name="bluemeanieseastereggs">{{cite web | url=https://www.mackido.com/EasterEggs/BlueMeanies.html | title=Apple Easter Eggs | publisher=MacKiDo | date=August 26, 1998 | accessdate=March 18, 2024 | first1=David K. | last1=Every | first2=Daniel | last2=Fanton}}</ref>

System 7.0 is the last version of the Macintosh operating system that was available at no charge and could be freely redistributed.  Although System 7 could be purchased from Apple, the cost was nominal and considered to only cover duplication and media. It was common for Macintosh dealers to allow customers to use the store's demo machines to copy System 7 install disks for the cost of a box of floppies.<ref>{{Cite web |title=Re: System 7.0 - Will it be on apple.com? |url=http://macgui.com/usenet/?group=53&id=83199#msg |url-status=live |archive-url=https://web.archive.org/web/20130525064529/http://macgui.com/usenet/?group=53&id=83199#msg |archive-date=May 25, 2013 |access-date=April 8, 2013}}</ref> CD-ROM magazines such as ''Nautilus'' included System 7 on their disks. After Mac users downloaded thousands of copies of System 7 from online services such as [[AOL]], [[CompuServe]], and [[GEnie]], Apple surveyed the services and based on this popularity started selling the Mac OS as a retail product with System 7.1.  Apple continued charging for major operating system upgrades until the release of [[OS X Mavericks]] in 2013.

==Version history==
Soon after the initial release of System 7, the 7.0.1 minor update was released in October 1991, which updated the Portable and Brightness control panels, added the Caps Lock extension - which showed an up-pointing arrow on screen if the Caps Lock key was depressed on PowerBooks - and added the Cache Switch control panel in addition to RAM disk and sound management optimizations for [[Motorola 68040|68040]] systems. Three small patches called "System 7 Tune-Up" also followed, which initially added the extension "System 7 Tuner" that improved memory management by quitting unused items, like applications and [[AppleTalk]], and added "minimum" and "preferred" memory allotments to an application's "Get Info" box in its 1.0 version.<ref>{{Cite web |title=System 7 Tune-Up - TidBITS |date=January 13, 1992 |url=https://tidbits.com/1992/01/13/system-7-tune-up/ |url-status=live |archive-url=https://web.archive.org/web/20220515235643/https://tidbits.com/1992/01/13/system-7-tune-up/ |archive-date=May 15, 2022 |access-date=May 15, 2022}}</ref> This would be followed by version 1.1, which included [[LaserWriter]] driver version 7.1.1 and added a hidden extension called "Tuna Helper", intended to fix the "disappearing files" bug in which the system would lose files.<ref>{{Cite web |title=Tune-Up 1.1, Just Get It - TidBITS |date=April 6, 1992 |url=https://tidbits.com/1992/04/06/tune-up-1-1-just-get-it/ |url-status=live |archive-url=https://web.archive.org/web/20220515235641/https://tidbits.com/1992/04/06/tune-up-1-1-just-get-it/ |archive-date=May 15, 2022 |access-date=May 15, 2022}}</ref> The final release, 1.1.1, included everything 1.1 included but also added the [[StyleWriter]] 7.2.2 printer drivers, [[Chooser (Mac OS)|Chooser]] 7.1 and a minor update to Tuna Helper.<ref>{{Cite web |title=Tune-Up Notes - TidBITS |date=April 20, 1992 |url=https://tidbits.com/1992/04/20/tune-up-notes/ |url-status=live |archive-url=https://web.archive.org/web/20220515235641/https://tidbits.com/1992/04/20/tune-up-notes/ |archive-date=May 15, 2022 |access-date=May 15, 2022}}</ref><ref>{{Cite web |title=System 7.1 update guide |url=https://manuals.info.apple.com/MANUALS/1000/MA1470/en_US/0302799Sys71UpdateGuide.pdf |archive-url=https://web.archive.org/web/20171018072032/https://manuals.info.apple.com/MANUALS/1000/MA1470/en_US/0302799Sys71UpdateGuide.pdf |archive-date=October 18, 2017}}</ref>

===System 7.1===
In August 1992, the 7.1 update was released.  This is the first version of the system software that Apple charged money for.  Of this change, [[David Pogue]] wrote:<ref name="system-software-museum">{{Cite book |last=Pogue |first=David |author-link=David Pogue |url=http://www.toddp.com/classic/Software%20Install/Apple%20Support%20Documents/Macintosh%20Secrets/Mac%20Secrets%204th%20ed./ch06.pdf |title=MacWorld Macintosh Secrets 4th edition - Chapter 6: The System Software Museum |date=January 1997 |access-date=October 18, 2017 |archive-url=https://web.archive.org/web/20171017214028/http://www.toddp.com/classic/Software%20Install/Apple%20Support%20Documents/Macintosh%20Secrets/Mac%20Secrets%204th%20ed./ch06.pdf |archive-date=October 17, 2017 |url-status=live}}</ref>{{rp|225}}

{{blockquote|text=System 7.1 was remarkable for another reason, too: It was the first system software update Apple didn't give away. You had to buy it, much to the fury of user groups and online services that had gotten used to making each new system release available to everybody. Backing down in the face of the protests, Apple eventually offered the System 7.1 upgrade kit to user-group and online service members for less than $30. But the writing was on the wall: Apple was jealous of Microsoft, a system-software superstore to the world. Many wondered if the upgrade was even worth it. System 7.1 incorporated a huge number of changes, but the vast majority were deep-seated, core-level rewrites that added no usefulness to standard American Mac users.|author=David Pogue|title=''MacWorld'' ''Macintosh Secrets'', 4th edition}}

New to 7.1 is the Fonts folder.<ref>{{Cite web |last=Howard Bear |first=Jacci |date=November 19, 2018 |title=Here's How to Find Font Files on Macs or in Windows |url=https://www.lifewire.com/locate-font-files-1074150 |url-status=live |archive-url=https://web.archive.org/web/20190425201608/https://www.lifewire.com/locate-font-files-1074150 |archive-date=April 25, 2019 |access-date=April 25, 2019 |website=Lifewire |language=en |quote=The default location for all System fonts in System 7.1 and later is the Fonts folder inside the System folder.}}</ref> This replaced the often time-consuming method of dragging fonts to and from the System file, introduced in System 7.0; it also replaced the [[Font/DA Mover]] application from System 6, which could also be used with 7.0. System 7.1 also included a lot of internal changes to support the internationalization of dates, times, and numbers.  It was also the first version to support "Enablers", which removed the requirement to release a new version of the system software every time new hardware was released.

A set of specialized versions of 7.1, ranging from 7.1P1 to 7.1P6 (excluding 7.1P4) were created and included with various [[Macintosh Performa|Performa]] models that were already available or were released after 7.1.  These specialized versions included [[At Ease]], Launcher, and some other changes that were integrated into later versions of the system software.

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 on slightly older machines due to its memory footprint, System 7 Pro barely fit into any Macintosh computers of the time. It was most commonly used for its minor bug fixes rather than its new functionality.

Apple co-founded the [[AIM alliance]] (Apple, IBM, and Motorola) in 1992, shortly after the release of System 7 in 1991, and started developing [[PowerPC]]-based machines that later became the [[Power Macintosh]] family. Support for these machines resulted in System 7.1.2.

System 7.1.2 was never offered for retail sale; it shipped with the first batches of the PowerPC Macs and a 68k version shipped with a small number of Quadra 600 series systems. Later shipments shipped with System 7.5 instead.

System 7.1.2P was the same as 7.1.2 and shipped with the [[Macintosh Quadra 630|Performa 630, LC 630, and Quadra 630]] models that were released between July and November 1994.

===System 7.5===
On September 12, 1994, '''System 7.5''' was released with bug fixes from previous updates and several new features:

*An updated startup screen with a progress bar
*A new interactive help system called [[Apple Guide]]
*A clock in the menu bar (from the third-party freeware control panel SuperClock!)
*An Apple menu item called [[Stickies (software)|Stickies]] (formerly a third-party application called "PasteIt Notes"), which provided virtual [[Post-It Note]]s
*[[WindowShade]], another former third-party shareware control panel, provided the ability to condense a window down to its title bar. It was introduced as a "minimize" feature to compete with Windows 95 as Mac OS had no taskbar or dock.
*[[MacTCP]] was bundled, enabling any Macintosh to connect to the [[Internet]] out of the box for the first time.
*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]]) was enabled on desktop Macintosh models for the first time. It had previously only been included with the PowerBook series.
*A new Desktop Patterns control panel allowed for tiled patterns up to 128x128 pixels with 8-bit color; previous versions were limited to 8x8 pixel tiles with a maximum of eight possible colors. Similar functionality was found on earlier system versions exclusive to [[Macintosh Performa|Performa]] models and was housed in the General Controls panel.
*The Extensions Manager (enabling the user to turn extensions and control panels on and off; also based on a formerly third-party control panel)
*[[Apple Open Collaboration Environment|PowerTalk]], a system-level email handling service and the originator of the [[Keychain (software)|Keychain]] system. 
*The Launcher, a [[Control panel (Mac OS)|control panel]] containing shortcut buttons for frequently used programs (in a manner akin to the [[macOS]] [[Dock (macOS)|Dock]])
*A hierarchical Apple menu (folders within the Apple Menu Items folder would expand into submenus showing their contents. Again, based on a third party control panel; HAM by Microseeds publishing<ref>{{Cite web |title=Classic Mac Wares: MenuChoice 2.1 |date=November 17, 2000 |url=http://lowendmac.com/wares/menuchoice.html |url-status=live |archive-url=https://web.archive.org/web/20070808135500/http://lowendmac.com/wares/menuchoice.html |archive-date=August 8, 2007 |access-date=December 14, 2007}}</ref>)
*System-wide drag & drop for text and other data (selections can 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
*For the PowerPC only, an advanced, 3d [[NuCalc|Graphing Calculator]], secretly developed at Apple by a former third party contractor<ref>{{Cite web |title=The Graphing Calculator Story |url=http://www.pacifict.com/Story/ |url-status=live |archive-url=https://web.archive.org/web/20080118235558/http://www.pacifict.com/Story/ |archive-date=January 18, 2008 |access-date=December 14, 2007}}</ref>
*Support for [[OpenDoc]]

System 7.5 is codenamed "Capone", a reference to [[Al Capone]] and "Chicago", which is the codename for Microsoft's [[Windows 95]] and is also the name of the default system font in Mac OS until version 8.<ref name="Apple Confidential">{{cite book |last=Linzmayer |first=Owen |url=https://books.google.com/books?id=mXnw5tM8QRwC |title=Apple Confidential 2.0: The Definitive History of the World's Most Colorful Company |publisher=No Starch Press |date=2004 |isbn=1-59327-010-0}}</ref>{{rp|56}}

System 7.5.1 is primarily a bug fix of 7.5 but also introduced a new "Mac OS" startup screen in preparation for [[Macintosh clone|Mac clones]].

System 7.5.2, released only for the first [[Peripheral Component Interconnect|PCI]]-based Power Macs, introduced Apple's new networking architecture, [[Open Transport]].

System 7.5.3 is a major bug-fix update that also included [[Open Transport]] for other PowerPC-based machines and some 68k-based machines. 7.5.3 improved the 68k emulator, and added translucent dragging to the Drag Manager. It included the first version of [[Control Strip]] to be compatible with all Macs. This was the first version of Mac OS to support [[Symmetric multiprocessing|SMP]] (9500/MP).

System 7.5.3 Revision 2 included performance enhancements; better reliability for PowerBooks using the third-party RAM Doubler program; improved reliability for PowerBook 500, 2300, and 5300 series computers with the PowerPC Upgrade Card; improved reliability when using the Startup Disk control panel; and improved reliability when copying files to 1&nbsp; GB hard disks.

System 7.5.3 Revision 2.1 was shipped with the [[Macintosh Performa|Performa]] 6400/180 and 6400/200; this particular release is specific to these machines as there was stability problems with System 7.5.3 Release 2 on the new hardware, especially with the video card and transferring files over LocalTalk.<ref name="system-software-museum" />{{rp|page=235}}

System 7.5.4 was pulled due to a mistake at Apple, in which some components were not included in the installer.

System 7.5.5 included significant performance improvements for virtual memory and memory management on PowerPC-based Macs, including the elimination of one type 11 error.{{clarify|date=January 2023}} Also included are several reliability improvements, such as fixes for Macs using floppy disks equipped with a DOS compatibility card, improved hard disk access for PowerPC PowerBooks and Performa 5400 through 9500 computers, fixes for Macs that included an Apple TV Tuner or Macintosh TV Remote Control, improvements to LocalTalk and networking (especially for the Performa 5400 and 6400), fixes to system startup for the faster 180&nbsp; MHz Macs (which included PowerPC 604 or 604e processors), improved reliability when using sound-intensive applications on Quadra or Centris computers that contained the PowerPC upgrade card, and improved stability when using multiple background applications and shared printers on a network. System 7.5.5 is also the last System 7 release that can run on 68000-based Macs such as the Macintosh Plus and Macs with ROMs that lack support for 32-bit addressing such as [[Macintosh IIcx]]. 7.6 and later required a 68030 processor and 32-bit-addressing-capable ROM and will automatically turn on 32-bit addressing on boot.<ref>{{Cite web |last=Hoffman |first=Ilene |date=December 14, 2000 |title=Mac Corner: Your Mac OS, part 2 |url=http://www.techrepublic.com/article/mac-corner-your-mac-os-part-2/5030860 |archive-url=https://web.archive.org/web/20110308203756/http://www.techrepublic.com/article/mac-corner-your-mac-os-part-2/5030860 |archive-date=March 8, 2011}}</ref>

===Mac OS 7.6===
Mac OS 7.6 (codenamed "Harmony") is the final major update, released in 1997. With 7.6, the operating system was officially called "Mac OS" instead of "System". New features include a revamped Extensions Manager, more native PowerPC code for Power Macs, more bundled Internet tools and utilities, and a more stable Finder with increased memory allocation.<ref>{{Cite web |title=Mac OS 7.6, Will it be worth it? |url=http://www.themacintoshguy.com/mactips/archive/tip13.shtml |url-status=live |archive-url=https://web.archive.org/web/20101222120836/http://themacintoshguy.com/MacTips/archive/tip13.shtml |archive-date=December 22, 2010 |access-date=July 27, 2011}}</ref> In this version, the [[Apple Open Collaboration Environment|PowerTalk]] feature added in 7.5 was removed due to poor application support, and support for a large number of older Macintosh models was dropped, including those with a Motorola 68000 or 68020.

'''Mac OS 7.6.1''' ported the 68k exception handling routines to PowerPC, turning type 11 errors into less harmful errors (type 1, 2, or 3, usually) as crashing applications would more often terminate safely instead of crashing the operating system.<ref>technote 1096</ref>

Through this period, Apple had been attempting to release a completely new "modern" operating system, named [[Copland (operating system)|Copland]]. When the Copland project was abandoned in 1996, Apple announced plans to release an OS update every six months until [[Rhapsody (operating system)|Rhapsody]] (which would by 2001 evolve into what was released as [[macOS|Mac OS X]]) shipped.<ref>{{Cite web |title=YouTube - Macworld Boston 1997 | website=[[YouTube]] |url=https://www.youtube.com/watch?v=PEHNrqPkefI |url-status=live |archive-url=https://web.archive.org/web/20161124213936/https://www.youtube.com/watch?v=PEHNrqPkefI |archive-date=November 24, 2016 |access-date=November 28, 2016}}</ref> Two more releases were shipped, now officially branded as Mac OS: Mac OS 7.6 and the minor bug fix 7.6.1. Future versions were released as [[Mac OS 8|Mac OS 8–8.6]] and [[Mac OS 9|Mac OS 9–9.2]].

Released during a troubled time in Apple's history, 7.6 is known for several bugs, such as the inability to customize what components are installed to the system<ref>{{Cite web |title=System 7.5 and Mac OS 7.6: The Beginning and End of an Era - LowEndMac |date=June 27, 2014 |url=https://lowendmac.com/2014/system-7-5-and-mac-os-7-6-the-beginning-and-end-of-an-era/ |url-status=live |archive-url=https://web.archive.org/web/20220408084846/https://lowendmac.com/2014/system-7-5-and-mac-os-7-6-the-beginning-and-end-of-an-era/ |archive-date=April 8, 2022 |access-date=May 15, 2022}}</ref> and its tendency to crash on some systems when they are shut down while a RAM disk is in use.<ref>{{Cite web |title=RAM Disk Fix utility posted - CNET |url=https://www.cnet.com/tech/computing/ram-disk-fix-utility-posted/ |url-status=live |archive-url=https://web.archive.org/web/20220515235641/https://www.cnet.com/tech/computing/ram-disk-fix-utility-posted/ |archive-date=May 15, 2022 |access-date=May 15, 2022}}</ref>

==Releases==
{| class="wikitable"
|-
!Version number
!Release date
!Computer
|-
|7.0
|May 13, 1991
| 
|-
|7.0.1
|October 21, 1991
|[[Macintosh Quadra]] 700/900/950<br/>[[Macintosh Classic II]]<br/>[[PowerBook 100]]<br/>[[PowerBook 140]]<br/>[[PowerBook 170]] and some others
|-
|7.1
|August 28, 1992
|[[Macintosh IIvx]]<br/>[[PowerBook 180]]<br/>[[Macintosh IIvi]]
|-
|7.0.1P
|September 14, 1992
|[[Macintosh Performa 200]]<br/>[[Macintosh Performa 400]]
|-
|7.1P
|October 19, 1992
|[[Macintosh Performa 600]]
|-
|7.1P2
|April 12, 1993
|[[Macintosh Performa 405]]<br/>[[Macintosh Performa 430]]<br/>[[Macintosh Performa 450]]
|-
|7.1P3
|October 18, 1993
|[[Macintosh Performa 410]]/460/475/550
|-
|7.1.1 (Pro)
| rowspan="2" |October 21, 1993
| 
|-
|7.1.1
|[[PowerBook Duo]] 250/270c<br/>[[PowerBook]] 520/540
|-
|7.1P5
|December 1, 1993
|[[Macintosh Performa 560]]
|-
|7.1P6
|February 1, 1994
|[[Macintosh Performa 575]]
|-
|7.1.2
|March 14, 1994
|[[Power Macintosh 6100]]<br/>[[Power Macintosh 7100]]<br/>[[Power Macintosh 8100]]
|-
|7.1.2P
|July 18, 1994
|[[Macintosh Quadra 630|Quadra 630]]
|-
|7.5
|September 12, 1994
|[[Macintosh LC]] 580
|-
|7.5.1
|March 23, 1995
|[[Power Macintosh 6200]]
|-
|7.5.2
|June 19, 1995
|[[Power Macintosh 9500]]
|-
|7.5.3
|January 1, 1996
|[[Power Macintosh 5400]]
|-
|7.5.3 Revision 2
|May 1, 1996
| 
|-
|7.5.3 Revision 2.1
| rowspan="2" |August 7, 1996
|[[Power Macintosh 6400|Performa 6400]]
|-
|7.5.3 Revision 2.2
|[[Power Macintosh 9500/200]]<br/>[[Performa 6360]]
|-
|7.5.5
|September 27, 1996
|[[Power Macintosh 5500]]
|-
|7.6
|January 7, 1997
|[[PowerBook 3400c]]
|-
|7.6.1
|April 7, 1997
|[[PowerBook 2400c]]<br/>[[Twentieth Anniversary Macintosh]]
|}

==Timeline==
{{Timeline of Macintosh operating systems}}

==See also==
* [[List of Apple operating systems]]
* [[List of Macintosh software]]
* [[Inside Macintosh]]
* [[Mini vMac]]
* [[Project Star Trek]]

==Notes==
{{notelist |refs=
{{efn|name="n1"|Project leaders Erich Ringewald<ref name="Apple: The Inside Story"/>{{rp|96}} and Mike Potel<ref name="Inside Taligent Technology">{{cite book |first1=Sean |last1=Cotter |first2=Mike |last2=Potel |url=https://www.wildcrest.com/Potel/Portfolio/InsideTaligentTechnology/WW6.htm |title=Inside Taligent Technology |publisher=Addison-Wesley |date=1995 |isbn=0-201-40970-4 |oclc=1072525751 |access-date=February 10, 2019}}</ref>{{rp|xiii,6}} date the start of Pink as "March 1988" or "early 1988", but ''Apple Confidential 2.0'' says "March 1987".<ref name="Apple Confidential"/>{{rp|69}}}}
}}

==References==
{{reflist}}

===Bibliography===
* Amit Singh, [https://books.google.com/books?id=K8vUkpOXhN4C ''Mac OS X Internals: A Systems Approach''], Addison-Wesley, 2007.

==Further reading==
* Harry McQuillen, ''10 Minute Guide to System 7'' (1991), {{ISBN|0-672-30033-8}}
* Stuple, S. J., ''Macintosh System 7.5 For Dummies Quick Reference'' (1994), {{ISBN|1-56884-956-7}}
* Bob Levitus, ''Macintosh System 7.5 for Dummies'' (November 1994), {{ISBN|1-56884-197-3}}
*{{webarchive|url=https://web.archive.org/web/20031004113439/http://developer.apple.com/technotes/os/os_05.html|date=October 4, 2003|title=System 7.1, System Update 3.0 - Technical Note OS05}} from [[Apple Inc.|Apple]]
*{{webarchive |url=https://web.archive.org/web/20010804041320/http://developer.apple.com/technotes/ov/ov_21.html|date=August 4, 2001|title=System 7.5 - Technical Note OV21}} from [[Apple Inc.|Apple]]
*{{webarchive|url=https://web.archive.org/web/20040429090120/http://developer.apple.com/technotes/os/os_07.html|date=April 29, 2004|title=System 7.5 Update 1.0 - Technical Note OS07}} from [[Apple Inc.|Apple]]
*{{webarchive|url=https://web.archive.org/web/20040628025311/http://developer.apple.com/technotes/tn/tn1017.html|date=June 28, 2004|title=System 7.5 Update 2.0 and System 7.5.3 - Technical Note TN1017}} from [[Apple Inc.|Apple]]
*{{webarchive|url=https://web.archive.org/web/20040824052006/http://developer.apple.com/technotes/tn/tn1050.html|date=August 24, 2004|title=System 7.5.3 Revision 2 - Technical Note TN1050}} from [[Apple Inc.|Apple]]
*{{webarchive|url=https://web.archive.org/web/20040627115141/http://developer.apple.com/technotes/tn/tn1069.html|date=June 27, 2004|title=System 7.5.5 - Technical Note TN1069}} from [[Apple Inc.|Apple]]
*{{webarchive |url=https://web.archive.org/web/20031207162734/http://developer.apple.com/technotes/tn/tn1090.html|date=December 7, 2003|title=Mac OS 7.6 - Technical Note TN1090}} from [[Apple Inc.|Apple]]
*{{webarchive |url=https://web.archive.org/web/20031208204957/http://developer.apple.com/technotes/tn/tn1096.html|date=December 8, 2003|title=Mac OS 7.6.1 - Technical Note TN1096}} from [[Apple Inc.|Apple]]

==External links==
* [http://www.system7today.com/ System 7 Today]
* [https://www.lowendmac.com/oldmac/compact3.html The Compact Mac Trio: System 6 or 7?]

{{S-start}}
{{Succession box
 | title = System 7/Mac OS 7
 | years =1991
 | before = [[System 6]]
 | after = [[Mac OS 8]]
}}
{{S-end}}

{{Classic Mac OS}}
{{Apple Inc. operating systems}}

[[Category:1991 software]]
[[Category:Classic Mac OS]]
[[Category:PowerPC operating systems]]