1997 Mac OS 7.6.0 (Harmony) (PPC)

1997 Mac OS 7.6.0 (Harmony) (PPC)

Mac OS 7.6
was released on January 7, 1997. Mac OS 7.6 is the last major release of System 7. Starting at this operating system, the "System" designation was no longer used by Apple, but was instead replaced by "Mac OS".

Its major enhancements came in the areas of virtual memory, memory management, the File Manager's caching scheme and the PowerPC Resource Manager routines. Also, the system's memory allocation scheme for some of its more frequently-used shared libraries were streamlined to take advantage of file mapping when virtual memory was on, a new functionality was implemented in Extensions manager, and a new Mac OS Installer -- the "umbrella" installer -- walks users through a safer installation process, including disk integrity checks, leading to less restarts.

QuickTime 2.5, OpenDoc 1.1.2, Open Transport 1.1.1 and Cyberdog 1.2.1 were integrated in Mac OS 7.6.

At the same time, support for classic networking and PowerTalk were discontinued.


With Mac OS 7.6 came Finder 7.5.6, which included the following enhancements:

The System contained other enhancements as well:

  • The Assistant Toolbox is now integrated into the System file.
  • The Code Fragment Manager now has a simplified algorithm for finding shared libraries.
  • When a 720K diskette is being reformatted as a DOS disk, an error now appears informing the user that the operating is not allowed.
  • The Display Manager's DisplayLib has been integrated into the System.
  • In the Drag Manager, DragLib has been integrated into the System.
  • File Manager was given major enhancements. A task has been added to the File Manger's disk cache that periodically removes dirty cache blocks. A new file system cache (96K) will be loaded at startup should extension be disabled. Volume sizes up to 2 TB are supported on all Macs with a Motorola 68040 or PowerPC chip, but those on the Motorola 68030 chip are still limited to 4 GB volumes.
  • In the Font Manager, an obscure bug was fixed involving multi-byte character systems.
  • Memory management was improved greatly. On PowerPC systems, the Modern Memory Manager is always active and the classic 68K Memory Manager is no longer available. Only 32-bit addressing is supported; 24-bit code was removed. The Modern Memory Manager now communicates directly to the Virtual Memory Manger.
  • The Menu Manager was given minor changes.
  • Screen shots were enhanced: it became possible to capture a region of the screen instead of the entire screen. Additionally, when the control key was held down, the screen shot was saved to memory (Clipboard) instead.
  • Minor enhancements were seen in the Process Manager.
  • The Resource Manger had been integrated into the System file. Routines have also been simplified to reduce execution time.
  • StringToExtended and StringToFormatRec routines were corrected in Script Manger 7.5.
  • In terms of the SCSI Manager (PowerPC), an error involving a SCSI Manager hang during periods of high network activity on systems with the Power Macintosh Card 1.0 installed had been corrected.
  • Sound Manager was integrated into the System file.
  • Standard File received a minor bug-fix.
  • StdCLib was enhanced, with Mac OS 7.6 introducing a new version of the library replacing the ROM library, and StdCLib was integrated into the System file. Most of the features and corrections provided by StdCLib 3.4.3 are realted to the handling of invalid parameters.
  • System Error Alert was fixed; this was involved with the System "bomb" dialogue box. Cases where the "bomb" dialogue box turned out to be flickering on screen were reduced.
  • QuickDraw was enhanced, with minor bug-fixes.
  • PowerMgrLib of the Power Manager was integrated into the System file.
  • TelephoneLib 3.0 of the Telephone Manager was moved into the System file.
  • Thread Manager's ThreadsLib 2.1.3 was integrated into the System file.
  • A minor error involving potential displaying of windows by extensions during system startup was corrected by a fix in Window Manager.

Desk accessories and other applications under the Apple menu were also corrected:

  • Apple System Profiler is now under the Apple menu instead of the previous location, the Apple Extras folder. However, Apple System Profile is not installed on Motorola 68030 machines.
  • Stickies got a memory partition size boost to 150K, correcting a few out-of-memory problems found in version 1.0.1 (the new version is 1.0.2).

Control panels were enhanced as well:

The control strip added a new module (CD Strip) interfacing with the CD drive, and Printer Selector 2.0 permitted users to choose from multiple desktop printers if Desktop Printing was installed.

Numerous system extensions were enhanced as well:

  • Invisible extensions were no longer executed at startup.
  • Apple CD-ROM extension version 5.3.1 adds generic support for 6x and beyond SCSI CD-ROM drives, corrects incompatiblities with some third-party drives, and corrects a problem that could occur when pausing an Audio CD during playback. Also, errors where the sleep timer would never expire, and where the CD-ROM could go to sleep while playing an Audio CD were corrected.
  • AppleGuide 2.1.1 adds support for multi-process guide files, which enables AppleGuide to be used in conjunction with OpenDoc documents.
  • Mac OS 7.6 ships with Apple Remote Access Client 2.1; however, Open Transport/PPP must be installed after Apple Remote Access Client 2.1 was installed.
  • AppleScript 1.1 is installed with Mac OS 7.6.
  • AppleShare Workstation Client 3.6.4 received some bug-fixes, including one where AppleShare was incorrectly allocating temporary memory for its caches.
  • Desktop Printing was upgraded to version 2.0.2.
  • OpenDoc was upgraded to version 1.1.2.
  • OpenDoc Essentials was upgraded to version 1.0.1.
  • OpenTransport became the only supported networking technology for Mac OS 7.6. Version 1.1.1 corrects the following: General OpenTransport functionality; backward-compatibility for the original AppleTalk and TCP/IP APIs; AppleTalk; TCP/IP; and Links. Classic networking APIs are emulated under OpenTransport.
  • OpenTransport/PPP was introduced with Mac OS 7.6.
  • QuickTime 2.5 was introduced, enhancing the QuickTime Music Architecture, improving movie playback, supporting more types of hardware accelerated video compression, multiple processors, closed-captioned text into a text track and low data rate audio capture, rendering QuickDraw 3D images, enhancing Alpha channel support, and enabling asynchronous JPEG display and CD auto start for audio CDs.
  • QuickDraw 3D was upgraded to version 1.0.6.
  • QuickDraw GX 1.1.5, introduced with Mac OS 7.6, is now compatible with ColorSync 2.x (and ColorSync, now that it is installed with the System, is no longer installed with the GX installer), and corrects errors relating to network PAP problems and PostScript and third-party spoolers.
  • Speech Manager was upgraded to version 1.5.

Several Apple Extras were also enhanced:

  • Cyberdog was upgraded to version 1.2.1.
  • Disk First Aid was upgraded to version 7.2.3 and is recommended for use on Mac OS 7.6.
  • Drive Setup 1.2.2 included a patch fixing a problem that could cause a hang on PowerPC models employing a MESH SCS controller.
  • MacsBug 6.5.4, while not included by default, is now required for use under Mac OS 7.6.

System requirements

Mac OS 7.6 can be installed on any Mac or Mac clone that is 32-bit clean and has at least a Motorola 68030 microprocessor. It cannot be installed, however, on computers that meet these requirements as a result of a hardware (or software) upgrade.

Mac OS 7.6 cannot be installed on all Motorola 68000 computers, and it is also incompatible with the Macintosh SE/30, Macintosh II, Macintosh IIcx and Macintosh IIx. In addition, current versions of Mode32 from Connectix do not allow Mac OS 7.6 to be installed on older Macintosh computers using this extension for 32-bit compatibility.

A typical installation requires about 70 MB of available hard disk space. At least 8 MB installed RAM is required, with an additional 8 MB through installed RAM or virtual memory.

Mac OS 7.6 cannot be installed over System 6.

System 7
System 7.0.x: 7.0 | 7.0.1 | Tune-Up 1.0 | Tune-Up 1.1 | Tune-Up 1.1.1
System 7.1.x: 7.1 | 7.1.1 (Pro) | 7.1.2 | 7.1.2P
System/Mac OS 7.5.x: 7.5 | 7.5.1 | 7.5.2 | 7.5.3 | 7.5.3L | 7.5.3 Rev 2 | 7.5.3 Rev 2.1 | 7.5.3 Rev 2.2 | 7.5.4 | 7.5.5
Mac OS 7.6.x: 7.6 | 7.6.1
Performa Systems: 7.0.1P | 7.1P | 7.1P1 | 7.1P2 | 7.1P3 | 7.1P4 | 7.1P5 | 7.1P6 | 7.1.2P
← System 6 | System 7 | Mac OS 8 →

Macintosh system software
Macintosh System: System 1 | System 2 | System 3 | System 4 | System 5 | System 6 | System 7
Mac OS: Mac OS 8 | Mac OS 9 | Mac OS X