| NOTE: This Technical Note has beenretired. Please see theTechnical Notes page for current documentation. |
  |
March 1995
IntroductionThis tech note provides the latest information on the components of the System7.5 System Software release. System 7.5 is a Reference System Softwarerelease, incorporating System Update 3.0, as well as other enhancements andupdates to System software, several Toolbox managers, and other features.System 7.5 provides a common code base for the System and Finder for bothMacintosh 680x0 and PowerPC computers System Reference releases. Because of thescope of System 7.5, this document provides a simplified listing of thecontents of System 7.5, with pointers to other sources of information. AppleScript 1.1 w/ Scriptable Finder System 7.5 includes the Scriptable Finder, which permits users to automatesystem tasks with their scripts. Several sample automated tasks are included inthe "Automated Tasks" and "More Automated Tasks" folders, together with severalnew `osax's. For Further Reference:
Apple Guide Apple Guide is Apple's electronic assistant that guides users throughprocedures one step at a time. You can create Apple Guide files for yourapplications using the Guide Maker authoring tool; Apple Guide also works withAppleScript to create Guide scripts. For Further Reference:
Display Manager The Display Manager allows users to dynamically change the arrangement anddisplay modes of the monitors attached to their Macintosh computers. TheDisplay Manager is documented inInside Macintosh: Advanced ColorImaging in the Display Manager chapter. Preliminary copies of thisdocumentation are on the developer CD. Drag Manager 1.1 Macintosh Drag and Drop permits users to select a block of data and drag it toanother location, either on the Desktop or in a file, even in other applications. Macintosh Drag and Drop is integrated into the System 7.5 System file. For Further Reference:
Control Strip API The Control Strip originally introduced in the PowerBook 540/520 series hasbeen extended to all Macintosh PowerBook computers.
Power Manager API The Power Manager gives Macintosh PowerBook users additional control over thepower management settings that currently are available in the PowerBook controlpanel. The application programming interface (API) is documented in thefollowing documents in the Power Manager folder:
PowerPC System 7.5 supports Macintosh computers, whether they use a Motorola 680x0processor or a PowerPC processor. System 7.5 includes additional PowerPCnative interfaces and software, including the Drag Manager, Thread Manager,Macintosh Easy Open, PowerTalk, and QuickDraw GX. sFor Further Information:
QuickDraw GX QuickDraw GX implements more intuitive printing and advanced text and graphicsupport. QuickDraw GX also provides for "portable digital documents" (PDDs) that do not require the presence of the creating application in order to open the file. For Further Reference:
All of the Inside Macintosh: QuickDraw GX books are available inprinted form. Here is a list of the Inside Macintosh: QuickDraw GX books:
Telephone Manager The Telephone Manager is part of the Macintosh Telephony Architecture (MTA),which provides a framework for the integration of personal computers and telephones. For Further Information:
Thread Manager 2.0 The Thread Manager is a System 7 extension that allows applications to make useof multithreading on Macintosh computers. Thread Manager 2.0 provides supportfor PowerPC. The Thread Manager is integrated into System 7.5's System file. sFor Further Reference:
Installer 4.0.3 The Installer permits application developers to write scripts that allow usersto easily install their applications. An Installer script is written using theMPW (Macintosh Programmer's Workshop) Rez language, and compiled using the MPWRez tool. The Installer 4.0.3 SDK is included on the developer CD, or on theMacOS SDK CD-ROM. SCSI Manager 4.3 SCSI Manager 4.3 provides asynchronous SCSI to all Quadra and Centris systemsfor the first time. In addition to the capabilities of the former SCSIManager, the SCSI Manager 4.3 additionally:
Please read the chapter "SCSI Manager 4.3" inInsideMacintosh: Devices. On a Power Macintosh 6100, 7100, 8100, or Quadra840AV/660AV, the SCSI Manager 4.3 extension is not necessary. On thesemachines, SCSI Manager 4.3 is in ROM, and the bug fixes to SCSI Manager 4.3 arein the System file. File System Extensions File System Extensions is a set of patches to the Finder and HFS which raisesthe current maximum volume size of 2 GB to 4 GB by treating volume sizes asunsigned values. It affects all Macintosh systems. * The exact upper limit of a volume's size is 4063 MB. This is due to the factthat the allocation block size must be a multiple of 512 bytes, and is treatedas an unsigned short in HFS. (It's stored as a long, and documented as a long,but actually treated as an unsigned short.) This means that the maximumallocation block size is $FE00. The maximum number of allocation blocks is$FFFF. Multiply these together to get 4063 MB. * The File Manager's routines to extend and truncate files had math problemsand would fail if the physical end-of-file was close to the 2 GB file sizelimit - the math problems were fixed. The bug wasn't seen under System 7.1.xand earlier systems because volumes were always less than 2 GB and files couldnever get large enough to show the bug because of the disk space used by theCatalog and Extents Overflow files. The PBHGetVInfo call was changed to pin the number of allocation blocksand free allocation blocks reported. For example, if the allocation block sizeis 0xfe00 (the largest possible under System 7.5), the total number ofallocation blocks and number of free allocation blocks is pinned to 0x8102.This change was made because a significant number of programs use signed mathto determine the volume size and free space and they didn't work if the realvalues were returned. The volume's Volume Control Block (VCB) still containsthe real number so code that needs the real value can still get to it. See theDTS sample code MoreFiles for a routine that shows how to access the VCB to getthe actual number of allocation blocks. The Finder's code that calculates volume size and free space was patchedto use unsigned math. The gestaltFSAttr Gestalt selector has a new bit defined to indicatewhen the 4 gigabyte changes have been made, gestaltFSSupports4GBVols. Here's acomplete list of the gestaltFSAttr bits that are currently defined. Not all arein use at this time (i.e., gestaltFSSupports2TBVols). gestaltFSAttr = 'fs ', /* file system attributes */gestaltFullExtFSDispatching = 0, /* all HFSDispatch selectors are passed through to file systems */gestaltHasFSSpecCalls = 1, /* File Manager has FSSpec calls */gestaltHasFileSystemManager = 2, /* has the File System Manager */gestaltFSMDoesDynamicLoad = 3, /* File System Manager supports dynamic loading */gestaltFSSupports4GBVols = 4, /* file system supports 4 gigabyte volumes */gestaltFSSupports2TBVols = 5, /* file system supports 2 terabyte volumes */gestaltHasExtendedDiskInit = 6, /* has extended Disk Initialization calls */ If a greater than 2 gigabyte volume is mounted under System 6, System 7.0.x, or System 7.1.x, nothing bad should happen. Some programs, including the Finder,will not work correctly because of their signed math problems and files thatare close to the 2 gigabyte file size limit may not be usable. The following hints are recommended to writers of device drivers Make sure your disk driver always uses ioPosOffset as a unsigned longvalue. This allows access to 4GB offsets. The File Manager will never usenegative offsets. When allowing a user to partition a volume 2 gigabytes or larger, put upa informational dialog to make sure they are aware that the volume should beused only with System 7.5 or later. Your driver should set the dNeedTime bit in the drvrFlags. The firsttime your driver receives an accRun Control request, it should call gestaltwith the gestaltFSAttr selector and check the gestaltFSSupports4GBVols bit. If 4 gigabyte volumes are not supported, then you should use the NotificationManager to let the user know that this disk should not be used with systemsearlier than System 7.5. Note: Apple's driver and Apple HD Setup do not implement the second and thirdsuggestions above. System Update 3.0 bug fixes and enhancements System Update 3.0 is a collection of bug fixes and enhancements delivered aspart of the System file. Under System 7.5, it is no longer a separate file. Technical Note "OS 05 - System Update 3.0" describes these bug fixes and enhancements. SimpleText The application known as TeachText has been greatly enhanced and renamedSimpleText; it is the integration of many changes made by various engineeringgroups at Apple. Integrating existing behavior means that not all behavior has been modified;also, despite some significant improvements SimpleText remains considerablyless than a full-fledged word processor. Its footprint is now 25K smaller,although the recommended RAM size is now 512K. SimpleText is designed to serve as the standard version of TeachText for users of System 7.5 and beyond. SimpleText/TeachText Changes Note that some changes were implemented prior to the name change to SimpleText.With these changes, SimpleText now:
SimpleText also includes the following changes for the System 7.5 release:
Speed ImprovementsSystem 7.5 includes the following improvements in speed and performance: Process ManagerThe System 7.5 version is a superset of the version thatshipped with PowerTalk. Among other improvements, this version of the ProcessManager switches context faster than previous process Managers, resulting in abetter user experience. Faster File CopyingA change was made to the buffer size that the Finder uses.Note that this is only for file copying from hard disk to hard disk (filescopied to and from floppies or foreign file systems are not affected). Opening windowsThis change is for windows in the Finder that have a largenumber of files (greater than 100). As the number of files increase thisspeed-up should be noticeable to the user. File System CacheThe cache now consolidates contiguous blocks before writing,reducing internally the number of driver calls necessary to flush the cache. Menu ManagerThis is an enhancement to the former MDEF; it now caches menusthat have been drawn. The result is that the next time a menu is pulled down,it is drawn immediately. The results vary according to the speed of the CPU.On slower machines, the effect is quite dramatic. System Software ComponentsThe following System Software Components are included as part of System 7.5:
There are various scripts included in System 7.5 that can be used toscript the Finder. Developers can create additional scripts. See "Scriptingthe Finder from Your Application" by Greg Anderson, develop magazine, issue 20.
PC Exchange permits Macintosh users to mount MS-DOS and Windows diskettes on their desktops.
Macintosh Easy Open is a System Software Extension that enables users tohave the Macintosh OS in conjunction with third party plug-in's to automatically translate documents. The system also allows the user to "route" translated documents to a preferred application and thus bypassing the "The application that created this document cannot be found" dialog box. Macintosh Easy Open 1.1 is included on the Macintosh OS SDK CD-ROM. Inthe Macintosh Easy Open folder you can find the following:
For Further Reference:
The Sound Manager is Apple's digital audio software solution that allowsany application to play and record sounds using the built-in sound hardwarefound on Macintosh computers. Sound Manager 3.0 is integrated into System7.5's System file. Refer toInside Macintosh:Sound for documentation.
PowerTalk 1.1 is Apple's implementation of the Apple Open CollaborationEnvironment, or AOCE. The AOCE Developer's Kit has been updated, and isavailable on the MacOS SDK CD-ROM. For Further Information:
For Further Information:
In the past, developing a foreign file system required extensive knowledgeof the Macintosh File Manager and how it used both documented and undocumentedlow-memory global variables and data structures. To solve this problem, Applehas written the File System Manager. To create a new foreign file system,developers no longer need to access undocumented portions of the Macintosh andinterface with the Macintosh file system through a 68000 register-basedinterface. Instead, they provide a foreign file system for a particular filesystem that works with the File System Manager. The File System Managerprovides a systematic way for one or more foreign file systems to interact with the Macintosh file system using high-level language interface. For Further Information:
System 7.5 includes a new disk initialization package. For further details, see theInside Macintosh:Files errata tech note. New Features- originally included only on Performa systemsThese features were originally included only on Performa systems, but now areprovided as part of the System 7.5 release for all systems in the new GeneralControls control panel device.
Allows the user to hide the Desktop (Finder) when in the background.
Provides options for the user to specify a file's default folder whenopening or saving a document: either the folder which contains the applicationthat creates the document, the last folder used in the application, or thedocuments folder. Setting the Documents option in the General Controlscontrol panel to "folder which contains the Application" provides essentiallythe same behavior as before System 7.5.
Prevents users from changing, removing or deleting files inside the System folder.
Prevents users from changing, removing or deleting files inside an application folder.
General Controls- enables or disables various system features
Incorrect Shut Down Warning lets users know if the computer was shut downincorrectly. In addition, the following two items originally included only on Performasystems are now standard parts of System 7.5.
Launcher is a separate control panel that permits the user to accesscommonly used items quickly.
The Shut Down desk accessory allows users to shut down from Apple Menu. Print DriversSystem 7.5 includes the optional installation package for QuickDraw GX. System7.5 provides drivers for both QuickDraw GX and non-GX systems. The Chooserdetermines which environment is currently active and only displays printersthat work in the current environment. The following print drivers are included with System 7.5:
Utilities/DAsNew Utilities and Desk Accessories are included in System 7.5. They helpdemonstrate new features available in System 7.5, such as Drag and Drop. Thefollowing are included on this CD:
Apple Menu Options is a control panel which extends the functionality ofthe Apple Menu. AMO adds hierarchical menus as well as menus which track recentapplications, recent documents, and recent servers.
Displays the time and date in the menubar. Located in Date & Timecontrol panel.
Allows users to hide windows by reducing the window to just the title bar.
Searches for files on a network and/or local volume and puts them in alist that is Drag Manager aware.
A new game that replaces the old puzzle.
Completely re-written as an application to be growable and Drag Manageraware; also displays more information about data types.
Completely re-written, is now Drag Manager aware, and supports featuressuch as finding text.
Allows users to put notes on the computer screen.
Control panel that allows users to manage extensions by allowing them toturn them on and off.
Desktop patterns are no longer part of the general control panels. Youcan select a new desktop pattern. You can add new desktop patterns by pastingthem in. Hold down the option key to select the background pattern for certainutilities. The resource 'ppat' of id 42 is used as the background pattern forcertain utilities such as the Calculator and Find File. Generic Macintosh NamingWhen doing a clean install of System 7.5, the name stored in the System File as'STR#' -16395 has been changed. (When installing System 7.5 over a previousversion of system software, this change does not take place.) Instead ofcontaining the explicit name of a particular CPU, the string contains "Macintosh", " Power Macintosh", or "Macintosh PowerBook". This change showsup in the Finder menu "About This Macintosh" as well as in various other code,such as the AppleTalk "responder" code, MacSNMP system MIB, etc. This changewas implemented to allow greater flexibility in creating new Macintosh modelsfor specific markets. The documentation inInside Macintosh:OperatingSystem Utiliteson page 1-27 is now incorrect. Progress bar at boot timeSystem 7.5 now includes a progress bar during boot time. Certain third partyextensions try to put up dialog boxes at boot time. Calling InitWindows duringboot time causes the progress bar dialog to disappear, yet the bar itselfcontinues to be drawn. This misbehavior is due to extensions which try to douser interaction at boot time. Apple strongly recommends that you do not usethe Window Manager or Dialog Manager until after the machine has completedbooting. Use the Notification Manager to inform the user of information fromwithin an extension, or consider rewriting your extension as an application andputting it in the startup items folder. Apple Menu Options and tracking filesApple Menu Options adds hierarchical menus to the Apple menu and adds threefolders, Recent Applications, Recent Documents, and Recent Servers, to the Apple Menu. The Recent Applications folder tracks all process launches except:
The Recent Documents folder is implemented by keeping track of basic systemactivity such as opening files, launching applications, and windowmanipulation. When one of these operations occurs, Apple Menu Options will tryto find a match between an open file and a window title. Matches are only madebetween files and windows opened by the same process. A file name and windowtitle are considered a match if the file name is substring of the window titleeither at the beginning of the window title, or at the end of the window title.For example, with an open file named "Document", the window titles "Document","Document (WP)", or "(WP) Document" are considered matches. When a match isfound, it is added to the Recent Documents folder. When files are opened, a check is made for an existing window with a matchingname. If a match is not found, the file is kept in a list of "unattached"files. When a window is opened or its title is changed, a check is made to seeif an "unattached" file opened by the same process matches. Files opened by theFinder (except control panels), files opened by background-only applications,files opened by INITs, files opened by DAs, PrintMonitor files, clipboardfiles, and alias files are not tracked. This means that if your application really wants to avoid having specific filesadded to the Recent Documents folder, it can use names for those files whichwon't be part of the window titles. For example, if your window title is goingto be "Thesaurus" then a file name of "US Thesaurus" won't be a match and so itwon't be added to the Recent Documents folder. The Recent Servers folder is implemented by checking each successfully mountedvolume to see if it is a server volume. Under System 7.5, only AppleSharevolumes are tracked. 8*24 GC cardThe acceleration which used to be provided by the 8*24 GC card control panel nolonger works with System 7.5. The 8*24 GC card continues to function, but noacceleration is provided. Loading Macsbug without Loading ExtensionsA new feature in System 7.5 allows you to load Macsbug without loadingextensions. As previously documented, holding down the shift key during theboot process prevents all extensions (including Macsbug) from loading. Holdingdown the option and shift keys together during the boot process allows Macsbugto load, but prevents all extensions from loading. Further Reference:
|
Technical Notes byDate |Number |Technology |Title |
