Mac OS 7.6

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.

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


 * The "About This Macintosh..." menu item was replaced with "About This Computer...", and references to "Macintosh" were replaced with "Mac OS".
 * Control panels and desk accessories that are, strictly speaking, application programmes (creator codes APPC and APPD) are now rerouted into the Control Panels folder and Apple Menu Items folder, respectively.
 * Larger number of files can now be displayed in a single window.
 * The Finder's Get Info window displays correct values for volumes with a size exceeding 2 GB.
 * An error where PCMCIA card icons were not reappearing following sleep on PowerBook 190, 540 and 5300 models was rectified.

The System contained other enhancements and changes 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 operation 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 of up to 2 TB are supported on all Macs with either a Motorola 68040 or PowerPC chip, while 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 greatly improved. On PowerPC systems, the Modern Memory Manager always remains active, while 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 Manager.
 * The Menu Manager received minor changes.
 * Screenshots 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 was integrated into the System file. Routines were also simplified in order 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 related 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:


 * Auto Power On/Off 1.1 includes a change affecting most desktops from the Macintosh Quadra 840av, forward.
 * ColorSync 2.1 includes new features such as Named Colour System support, hifi colour support, embedding profile by reference, and expanded bitmap formats.
 * Extensions Manager was given a huge update, bringing it to version 4.0.
 * Macintosh Easy Open has been renamed into Mac OS Easy Open and is bundled along with MacLinkPlus 8.1.
 * The Map control panel now adds Cork, Ireland and München, Germany to the cities database.
 * The Memory control panel no longer allows the Modern Memory Manager to be deactivated on PowerPC systems. The "Use 24-bit addressing" control is no longer available as 24-bit addressing is gone. Also, the minimum disk cache setting is now 96K.
 * The Monitors control panel got some bug-fixes regarding situations where some Macs would see an error when two attached monitors were configured at different colour levels (thousands and 256 colours) and when configuration settings for all attached monitors on systems with more than one monitor attached were not being saved.
 * When QuickTime was being installed, a new control panel, QuickTime Settings, was installed as of Mac OS 7.6, to allow users to configure various QuickTime parameters.
 * The Startup Disk control panel version 7.5.3 sets the PRAM values correctly on the Quadra 660av and 840av; user settings are kept. Also, multiple volumes with the same name but different custom icons now display correctly.

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 any Motorola 68000 computers, and it is also incompatible with the Macintosh SE/30, Macintosh II, Macintosh IIcx and Macintosh IIx. Mode32 from Connectix did 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.


 * Mac OS 7.6 can be installed over System 7.0 for the Macintosh IIci, Macintosh IIfx & Macintosh IIsi
 * Mac OS 7.6 can be installed over System 7.0.1 for the Macintosh Quadra 700, Macintosh Quadra 900, Macintosh Quadra 950, Macintosh LC II, PowerBook 140, & PowerBook 170
 * Mac OS 7.6 can be insalled over System 7.1 for the PowerBook 145, PowerBook 145B, PowerBook 160, PowerBook 165c, PowerBook 165, PowerBook 180, PowerBook 180c, Macintosh LC III, Macintosh LC 475, Macintosh LC III+, Macintosh LC 520, Macintosh LC 550, Macintosh IIvi, Macintosh IIvx, PowerBook Duo 210, PowerBook Duo 230, PowerBook Duo 250, PowerBook Duo 270c, PowerBook Duo 280, PowerBook Duo 280c, Macintosh Quadra 610, Macintosh Quadra 650, Macintosh Quadra 660AV, Macintosh Quadra 800, Macintosh Quadra 840AV, Macintosh Centris 610, Macintosh Centris 650, & Macintosh Centris 660AV
 * Mac OS 7.6 can be installed over System 7.1.1 for the Macintosh PowerBook 150, Macintosh PowerBook 520 Series, Macintosh PowerBook 540 Series & Macintosh LC 575.
 * Mac OS 7.6 can be installed over System 7.1.2 for the Power Macintosh 6100, Power Macintosh 7100 & Power Macintosh 8100.
 * Mac OS 7.6 can be installed over System 7.1.2P for the Macintosh Performa / LC / Quadra 630 Series.
 * Mac OS 7.6 can be installed over System 7.5 for the Macintosh LC 580.