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System 6 (also referred to as System Software 6) is a graphical user interface-based operating system for Macintosh computers. It was released in 1988 by Apple Computer, Inc. and is part of the classic Mac OS series of operating systems. System 6 was included with all new Macintosh computers until it was succeeded by System 7 in 1991. The boxed version of System 6 cost $49 when introduced.[2] System 6 is classed as a monolithic operating system. It features an improved MultiFinder, which allows for co-operative multitasking.

System Software 6
A version of the classic Mac OS operating system
Macintosh system 6.0.8.png
System Software 6.0.8
DeveloperApple Computer, Inc.
OS familyMacintosh
Source modelClosed source
Released to
April 1988; 31 years ago (1988-04)
Latest release6.0.8 / April 1991; 28 years ago (1991-04)[1]
Kernel typeMonolithic
Preceded bySystem 5
Succeeded bySystem 7
Support status
Unsupported, historic

Main featuresEdit


A new utility called MacroMaker was included with System 6.[3] When enabled, it allowed users to record mouse and keyboard input as "macros." MacroMaker had a unique user interface, which aimed to look and act like a tape recorder.[4] MacroMaker was criticized for its lack of features when compared to Microsoft's AutoMac III, which was already available commercially.[4] As MacroMaker only recorded the locations of mouse-clicks inside windows and not what was being clicked or exactly when, users soon found that it could not be used to automate more sophisticated programs. The pre-recorded clicks would miss buttons if they had moved or failed to appear upon playback.[4] In addition, MacroMaker had limitations in that it recorded the start and end locations of mouse movements but not the precise path of the movements, and its macros did not handle situations that required the macro to wait for a period of time before or after an action.[5] MacroMaker was not compatible with System 7, which marked the introduction of AppleScript as an alternative.


Cooperative multitasking made its Macintosh debut in March 1985 with a program called Switcher by Andy Hertzfeld, which allowed the user to launch multiple applications and switch between them.[6] Many programs and features did not function correctly with Switcher. Also, Switcher did not display windows of other applications beside the selected one. It was not included with the operating system, but was available from Apple as a separate purchase. Both System 5 and System 6 had a feature called MultiFinder instead,[7] which was much more mature and widely used in System 6. MultiFinder could be enabled or disabled, with a reboot. If disabled, the Finder would quit when the user launched another application, thus freeing RAM for it. If enabled, the system behaved as in the nowadays familiar multitasking tradition, with the desktop and windows of other applications in the screen's background.

Hardware supportEdit

System 6 included support for the Apple ImageWriter LQ and other PostScript laser printers. New software drivers allowed the ImageWriter LQ to be used on AppleTalk local area networks and supports use of tabloid, or B, size paper (11 in × 17 in (280 mm × 430 mm)).[3] System 6 also included QuickerGraf (originally called QuickerDraw), a piece of system software used to accelerate the drawing of color screen images on the Macintosh II. It was licensed to Apple and Radius Inc by its programmer, Andy Hertzfeld.[3]


System 6's Apple menu cannot be used to launch applications. The current application icon in the upper right-hand corner of the menu bar cycles between open applications; it is not a menu.[8] System 6 supports 24 bits of addressable RAM (random access memory), which allowed a maximum of 8 megabytes of RAM with no provision for virtual memory.[9] These limitations were fixed in System 7. The version of the HFS file system used by System 6 also has a volume size limit; it supports up to 2 gigabytes (GB) and 65,536 files on a volume.[10] This limitation was not increased until System 7.5 which first increased the limit to 4 GB.

The Trash (known as the "Wastebasket" in British versions) empties when the Finder terminates. If MultiFinder is not running, this occurs as soon as an application launches. Icons on the desktop in System 6 are not organized into a single folder, as in later operating systems. Instead, the system records whether each file is on the desktop or not.[11] This is inefficient and confusing, as the user cannot browse to the desktop in applications besides the Finder, even within the standard Open and Save As dialog boxes. Furthermore, these dialogs are primitive, mostly unchanged since 1984. The lack of aliases, shortcuts to files, was another limitation of file management on System 6.[12] Custom file and folder icons are also not supported. These problems were all remedied in System 7.

A maximum of 15 desk accessories may be installed at one time, including the Chooser, Scrapbook, and Control Panel. System 6 uses the Control Panel desk accessory to access all the installed control panels, which imposes severe user interface limitations.[13] Desk Accessories cannot be installed or removed within the Finder; this requires the Font/DA Mover utility. System 7 also fixed this. Control panels, however, are contained in separate files.

Few methods exist for interface personalization. The Finder allows each icon to be assigned a color, but the desktop background is limited to an 8x8 pixel color tiled pattern (color patterns were introduced in System 5[14]), and standard window frames are all black and white. However, many "INIT" extension files existed to add color and customization. System 7 later allowed the user to change the color and various other aspects of the user interface.[15] By 1989, the System 6 user interface was in need of a change.[15] In comparison to the NeXTSTEP operating system of the time, System 6 did not make use of sound, and its user interface presented several limitations in terms of file management and the way windows were displayed.[15]


The initial releases of System 6 were unstable; many third party software developers did not receive copies before its release, resulting in widespread compatibility problems.[2] At first, many common software programs such as Microsoft Excel, Microsoft Works and 4th Dimension were not fully compatible with System 6.[2] There were also software bugs in the Color Manager, Script Manager, and Sound Manager extension files. Apple announced that 66 bugs were fixed when the 6.0.1 update was released in September 1988.[16][17] However, a major bug involving text spacing of screen fonts was found in 6.0.1 after distribution began.[17] This led to the quick release of 6.0.2, which solved this problem. Some customers waited longer until moving to System 6 because of the poor reputation already gained.[18]


System 6 was officially supported by Apple for many different machines, some of which were shipped with System 6. It may be that some Apple computers for which System 6 was not officially supported may nevertheless be able to run it, perhaps with limitations.[19][20]

Macintosh Model Model Date 6.0.8[19] 6.0.7[19] 6.0.5[19] 6.0.4[19] 6.0.3[19] 6.0.2[19]
128K 1984 No No No No No No
512K 1984 No No No No No No
512Ke 1986 Yes[21] Yes[21] Yes[21] Yes[21] Yes[21] Yes[21]
Macintosh XL 1985 No No No No No No
Plus 1986 Yes Yes Yes Yes Yes Yes
SE 1987 Yes Yes Yes Yes Yes Yes
SE/30 1989 Yes Yes Yes No Yes Yes
Classic 1990 Yes Yes Yes Yes Yes[22] No
Classic II 1991 Yes: 6.0.8L[23] No No No No No
Portable 1989 Yes Yes Yes Yes Yes Yes
II 1987 Yes Yes Yes Yes Yes Yes
IIx 1988 Yes Yes Yes Yes Yes Yes
IIcx 1989 Yes Yes Yes Yes Yes Yes
IIci 1989 Yes Yes Yes Yes No No
IIfx 1990 Yes Yes Yes No No No
IIsi 1990 Yes Yes No No No No
LC 1990 Yes Yes No No No No
LC II 1992 Yes No No No No No
Quadra 700 1991 No No No No No No
Quadra 900/950 1991/1992 No No No No No No
PowerBook 100 1991 Yes: 6.0.8L[23] Partial: limited[20] Partial: limited[20] No No No
PowerBook 140
1991/1992/1993 No No No No No No

Version historyEdit

System Version[24] Release Date[24] Finder Version[24] MultiFinder Version[24] LaserWriter Version[24] Release Information[24]
6.0 April 1988[citation needed] 6.1 6.0 5.2 Initial Release
6.0.1 September 19, 1988 6.1.1 6.0.1 5.2 Release for Macintosh IIx (1988)
6.0.2 September 19, 1988 6.1 6.0.1 5.2 Maintenance Release
6.0.3 December 23, 1988[25] 6.1 6.0.3 5.2 Maintenance release with bug fixes for Apple File Exchange, Time Manager and other components. New York 18 and 24 fonts were removed.
6.0.4 September 20, 1989 6.1.4 6.0.4 5.2 Release for Macintosh Portable and IIci (1989)
6.0.5 March 19, 1990 6.1.5 6.0.5 5.2 Release for Macintosh IIfx (1990)
6.0.6 March 19, 1990 - October 15, 1990 6.1.6 6.0.6 5.2 Packed with early Macintosh IIsi, LC and Classic machines; contained bugs that caused the keyboard to stop working and prevented AppleTalk from working.[26]
6.0.7 October 15, 1990 6.1.7 6.0.7 5.2 Official release for Macintosh LC, IIsi and Classic (1990)
6.0.8 May 13, 1991 6.1.8 6.0.8 7.0 Updated printing software to match the printing software of System 7.0
6.0.8L March 23, 1992[23] 6.1.8 6.0.8 7.0 Used only on the Macintosh Classic, Classic II, LC, LC II, and PowerBook 100.


  1. ^
  2. ^ a b c Paden, Jake (November 1988), "Now we are six (System Software 6.0 for the Macintosh)", MacUser, p. 184
  3. ^ a b c Forbes, Jim (April 12, 1988), "Apple to enhance system software, desktop database.", PC Week, p. 11
  4. ^ a b c Beaver, David (July 19, 1988), "Some simpler solutions to making macros (MacroMaker and AutoMac III macro recorders for the Macintosh)", MacWEEK, p. 44
  5. ^ Heid, Jim; Norton, Peter (1989). Inside the Apple Macintosh. The Peter Norton Foundation series. Simon & Schuster, Inc. pp. 333–334. ISBN 0-13-467622-X.
  6. ^ Hertzfeld, Andy (2005), Revolution in the Valley, O'Reilly, pp. 243–251, ISBN 0-596-00719-1
  7. ^ Wiggins, Robert R. (March 1988), "All systems go (System Tools 5.0 with MultiFinder)", MacUser, p. 126
  8. ^ LeVitus, Bob (July 1991), "System 7.0: 10 reasons why you'll love it", Computer Shopper, p. 202
  9. ^ "Settling down with System 7 (Apple Macintosh operating system's compatibility with network operating systems and upgrading benefits)", The Local Area Network Magazine, p. 18, August 1991
  10. ^ "Macintosh: File System Specifications and Terms". Apple Inc. January 17, 2007. Archived from the original on May 8, 2008. Retrieved March 9, 2019.
  11. ^ LeVitus, Bob (March 1992), "Top ten secrets of System 7 (Beating the System)", MacUser, p. 213
  12. ^ Michel, Steve (May 14, 1991), "Aliasing: a file by any other name. (making duplicate files with minimal disk space) (System 7.0 Survival Guide)", MacWEEK, pp. S13
  13. ^ lead writer: Sharon Everson (October 1992), Inside Macintosh: More Macintosh Toolbox (Apple Technical Library) (PDF), Addison-Wesley, p. 779, ISBN 0-201-63243-8
  14. ^ Robert R. Wiggins, "All systems go. (Software Review) (System Tools 5.0 with MultiFinder.)", MacUser (March 1, 1988). Many of the cdev modules that come with System Tools 5.0 are for the Macintosh II, including a new one called "Color" that allows you to change the highlight color, the color used as a background when text or an icon is selected. The General cdev also adds the ability to set the desktop pattern color on a Macintosh II. '
  15. ^ a b c Crabb, Don (June 1989), "The Mac Interface: Showing Its Age", Byte, pp. 235–237
  16. ^ "System 6.0.1 set for distribution", MacWEEK, September 13, 1988
  17. ^ a b Perrow, Jonathan (September 20, 1988), "System 6.0 saga not over yet", MacWEEK, p. 2
  18. ^ "Managers go slow with System 6.0.2", MacWEEK, p. 2, October 25, 1988
  19. ^ a b c d e f g "System Software: Version Matrix, System 6.0.x to 7.0.1". Apple Inc. September 10, 1997. Retrieved April 22, 2008.
  20. ^ a b c "PowerBook & Macintosh Classic II: No Support for System 6". Apple Inc. November 30, 1994. Retrieved May 3, 2008.
  21. ^ a b c d e f "Macintosh 512Ke: Technical Specifications". Apple Inc. March 14, 2002. Retrieved May 3, 2008.
  22. ^ "The System in the New Machine". TidBITS Publishing Inc. November 19, 1990. Archived from the original on May 3, 2008. Retrieved May 4, 2008.
  23. ^ a b c "System 6.0.8L: ReadMe File (8/95)". Apple Inc. August 17, 1995. Archived from the original on April 26, 2012. Retrieved May 3, 2008.
  24. ^ a b c d e f "Macintosh: System Software Version History". Apple Inc. August 7, 2001. Archived from the original on April 20, 2008. Retrieved April 22, 2008.
  25. ^ "United States Macintosh System Software 6.0.3 - Change History".
  26. ^ "MacBulletin - Apple Pulls System 6.0.6". MacWorld Magazine. December 1990. p. 17. Cite magazine requires |magazine= (help)

External linksEdit