- Shopping Bag ( 0 items )
In addition to housing the brains of the operating system, the System Folder contains many of the components that load by default. These components include System Extensions, Extensions, Control Panels, Preferences, Startup Items, Shutdown Items, and Apple Menu Items. The following sections cover these components.
Although there are not many System Extensions, they are among the first items to load during the booting process. One of the most useful is MacsBug, a valuable tool that can tell you what process caused the system malfunction. When a system crashed or froze in the days before MacsBug, the user's only recourse was to reboot immediately. The user was given no chance to reboot gracefully, or-even more important-to learn exactly what caused the crash. Now that it's routine to run multiple applications simultaneously (especially Internet-based ones that can cause a system crash while running in the background), MacsBug is more valuable than ever. It can identify the culprit behind your problem and even allow you to quit the offending program from the MacsBug command line.
Rather than write a new operating system every time a software program is released or a system component is tweaked, developers create Extensions that plug into the system to increase functionality or improve performance. More than any other folder, the Extensions folder has a tendency to get out of control, gathering cryptically named files that eat away at precious system and memory resources.
The files stored in the Extensions folder load after System Extensions. Most Extension icons have the distinct puzzle-like appearance similar to those shown in Figure 2.4 (even the folder sports a puzzle-piece graphic). The most well-known Extensions are printer, peripheral, CD-ROM, video, and network drivers, but there are facetious ones as well, such as singing trashcans.
Occasionally, Extensions or Control Panels fail to load properly and cause the system to hang. This condition is termed an Extension conflict, although the problem may be isolated to a Control Panel. Previously, we discussed options for booting the system and one of these options is to boot with Extensions off. For clarification, this actually entails disabling both Extensions and Control Panels.
Weed out those useless Extensions. If for no other reason than to tighten your system performance, it's one of the best things that you, as a user or administrator, can do. Several Web sites define what these Extensions do and whether you can live without them. The Extensions Manager also can provide some information about these files, such as the creator and version number.
One of the biggest differences between Control Panels and Extensions is that Control Panels have windows or dialog boxes that allow you to change Control Panel settings. Control Panels are among the last of the system components to load. They often deal with the way that the system looks and behaves and include some screen savers, appearance managers, network configuration applications, and monitor settings. Control Panel icons, like Extension icons, also have a distinctive appearance, as shown in Figure 2.5.
If a programmer wants you to have some control over how an application runs within the system, he will write the code as a Control Panel. Otherwise, the code is written as an Extension.
Every application that launches on a Macintosh creates a preference file. Even if you used the application only once, decided that it didn't meet your requirements, and dragged it to the Trash, there is still a file in the Preferences folder that indicates how the program should be run in the future.
Information stored in a preference file can include options input by the user, such as preferred email address, custom toolbars, default views, and so on, as well as window positioning of a particular document. Applications that keep a list of recently used documents store this information in a preference file.
Most users do not need to interact with the Preferences folder unless something has stopped working within a particular application. Programs that hang when launching (and those that are not functioning normally) may have a corrupt preference file. In most cases, removing the preference and allowing the program to create a new one will solve the problem. You'll need to input some user preferences again, however. Make sure that important information-such as the IP number assigned to the machine, serial numbers for software, and configuration optionsis available or documented, should you have to delete important preferences.
If you have applications that you use every time you launch the machine (such as Web server software, Internet applications, or client programs), you may want to take advantage of the Startup Items folder. As the OS nears the end of the booting process, it looks to this folder to see if any applications should be launched. Although you can place the actual application in the folder, it's better for system security to use an alias.
You can place multiple items in the Startup Items folder. Because they are launched alphabetically, you can control the launch order by manipulating the first character in the name of an item. For example, adding a space before the first letter of BBEdit will cause it to launch before Adobe PhotoShop; adding a bullet character before the first letter of Fetch will cause it to launch after Outlook Express.
Just as the Startup Items folder runs the programs within it during the boot process, the Shutdown Items folder runs applications during shutdown. Common applications that run at this time are disk utilities, optimization programs, and virus protection-although any application placed in the Shutdown Items folder will run. You'll find more information on shutting down a little later in the chapter.
Apple Menu Items
The System Folder also is home to the Apple Menu Items folder. This folder contains the applications or aliases that are available under the Apple menu, which is located in the top-left corner of the screen. You can launch applications from the Apple menu simply by selecting them. Figure 2.6 shows the Apple menu under Mac OS 9.1.
As with any graphical interface, you must exercise care when shutting down the operating system. There are several ways to shut down a Macintosh properly.
The most common method is to select Shut Down from the Special menu, as illustrated in Figure 2.7. The system will begin closing open programs. If you have made changes to any open documents, the system will display a dialog box that asks whether you want to save the changes. When all applications are closed, the system will shut down and turn off the power. Older Macintoshes that have a power button will display a window, indicating that you can now turn off the computer.
You can also shut down the computer by pressing the power key. This method is often discovered by accident. The dialog box shown in Figure 2.8 will appear, asking if you're sure you want to shut down the computer and offering you the option to restart, sleep, or cancel the command. Notice that the default shuts down the system. If you press the Return or Enter keys at this point, the system will begin the shutdown process.
Finally, some Macintosh systems have a Shut Down option under the Apple menu. This option will effectively bring down the operating system gracefully. It is not included by default in Mac OS 9.1, but is often found on systems as legacy software.
Should you turn your computer off whenever it's not in use? In most cases, it's perfectly fine to leave a system running. In many workplaces, backup systems run during the night and cannot back up a computer that has been shut down. At home, however, it's better to turn off the system because most home computers have long periods of inactivity. Running them while not in use wastes energy. Keep in mind that restarting a computer also provides useful benefits like freeing up memory and removing hidden temporary files...
TIP: Never attempt to store essential OS components on removable media such as floppy disks or Zip cartridges, or on network volumes or file servers.
The System Folder, shown in Figure 1.1, contains the programs necessary for the operation of the OS as well as many folders (and a few files) that must be properly named in order for the OS to function.
The System Folder on your computer may look a bit different, depending on which OS components you've installed. In addition, it may house files and folders added by other software you have installed.
The Finder and the System suitcase are components that are critical to the booting of the OS (see Figure 1.2). They constitute the kernel of the OS and work in conjunction with Control Panels, Extensions, and System Extensions to provide access to the computer, network services, disks, and files, as well as to printing and other kinds of input and output.
TIP: For a detailed description of all the components of the System Folder, please see Chapter 2.
In addition to the OS itself and its associated files and folders, a default installation of Mac OS 9.1 includes over 2,000 files that constitute many additional applications, utilities, and documentation. These files fall into several broad categories:
Unlike the Finder and System suitcase, which are directly responsible for the low-level operation of your computer. The other components of the Mac OS are usually modular and upgraded by Apple after the initial release of the OS has reached consumers. These components add valuable functionality in areas such as networking and multimedia support. Mac OS 9.1 includes the components listed in Table 1.1.
Table 1.1 The modular components of Mac OS 9.1 that are not part of the low-level OS and may be easily updated....
The elements of the Mac OS user interface described in the following section demonstrate just how simple it can be to access the Internet from the Mac OS.
Internet Access Tools
Mac OS 9.1 comes with many tools to help you connect to the Internet. For example, Figure 1.5 shows several of the tools that assist in creating or modifying an Internet service provider account.
Sherlock 2 (Search Internet)
The old Find application has undergone a major upgrade. Now known as Sherlock 2, this application allows you to find information by name, by content on an indexed hard drive, or on the Internet. Sherlock 2's new capabilities, shown in Figure 1.6, show exactly how far Apple has extended the reach of the Mac OS. It's now possible to control information beyond the local file system with the same ease that has made the Mac OS famous.
You can now seek help using a Web browser-like interface, thanks to Apple's application of HTML technology to its new Mac Help. The searchable Help Viewer, shown in Figure 1.7, uses frames to display help topics on the left and detailed information on the right. Clickable hyperlinks direct you to additional information on a topic.
Translucent file names and the addition of an arrow to the alias icon are two recent improvements to the Mac OS icons. Both of these enhancements are shown in Figure 1.9. Translucent file names are much easier to read when viewed against a colored background; they're invisible against a white background. The addition of the arrow to the alias icon helps identify a file as an alias. As in previous versions of the Mac OS, the file name of an alias appears in italicized text. Because italic and regular styles can be hard to distinguish in some listview fonts, the arrow was added to eliminate any confusion.
While you're in the process of copying or making an alias, the cursor is enhanced with an additional visual clue: a small plus sign indicates copying and a small right arrow indicates aliasing. Figure 1.10 shows the Utilities folder being copied (left) and aliased (right).
Alternatively, a summary of a file may be created and sent to the clipboard by way of the contextual menu. Figure 1.12 shows a SimpleText document that has been summarized.
Users of Systems 6 and 7 were stuck with the old "System 7" appearance; then Mac OS 8 introduced the "Platinum" appearance. Now OS 9.1 maintains the framework for third-party software developers to create entirely new appearances (a feature which initially appeared in Mac OS 8.5). Figure 1.13 shows the effects of an appearance called Dimple from Power/Mac (www.powermac.co.uk).
Apart from the visual aspect of the new appearance, nothing has really changed. Windows, menus, and all mouse actions work the same, regardless of what Appearance Control Panel settings you choose.
NOTE: For more information on the Appearance Manager and themes, see Chapter 3.
The Preferences and View Options menus have been modified to consolidate several preferences configuration options into a single location. In addition, it's now possible to create a "Standard Views" option for each disk drive or folder; you can then use this option to control the View preferences for all enclosed folders. (This was possible in System 7, but not in Mac OS 8.0 or 8.1.) Figure 1.15 shows the View options for the List view.
This much-needed enhancement also enables you to easily change the options for one or more of the enclosed folders on a folder-by-folder basis while retaining the default view for the others.
NOTE: For additional information on how to customize your Desktop, file, and folder views, turn to Chapter 3.
Users who prefer to use any and all keyboard shortcuts whenever possible will be relieved to know that the menu changes do not affect keyboard equivalents. Figure 1.16 shows one of our favorite keyboard equivalents, throwing a selected item in the Trash by pressing Command+Delete....
What do you need to use this book most efficiently? First, this book assumes you have significant experience with the Macintosh family of computers, the Internet, and some level of interest in cross-platform connectivity and interoperability. This last point may not seem too relevant for many readers, but let us suggest that we all need to realize that the Mac OS will probably never reach the level of monopoly that the various versions of Microsoft Windows enjoy, and that the best OS is often the one that gets along best with all the others. To this end, we're assuming that you share this view on the state of things and are interested in using the Mac OS to communicate and share data with other operating systems, and that you have some experience with these operating systems.
Next, it assumes that you have a Mac with a PowerPC processor, which is required to run Mac OS 8.6 and higher. Finally, this book assumes that you have experience with, and connectivity to, the Internet. You may have a permanent connection through your computer at work, or you may be one of the lucky ones with Internet access through a cable modem, DSL, ISDN, or frame relay. But even us poor souls with a modem and a PPP connection can still qualify.
The following overview of the book's chapters will help you see how we've organized things; feel free to jump right into the middle if that's what you think you need. Each chapter is self-contained, but the first paragraph or so will make it clear if you need to see a previous chapter in order to proceed with the present chapter:
We welcome your feedback on this book. You can email us directly at mbell@MacOSBook.com and dsuggs@MacOSBook.com. Errata, updates, and more are available at www.MacOSBook.com.