We've covered the basic functions of the Finder from stem to stern. It's now time to delve into the Mac OS's system preferences. Like the control panels on Windows PCs, system preferences govern much of the behavior of the Mac OS and the Mac's peripherals.

To begin your explorations, click the Apple menu in the top-left corner of your Mac's display and choose System Preferences. Optionally, click the System Preferences icon in the Dock.

When the System Preferences window appears, you'll see that the items within it (which are called preference panes or pref panes, but I sometimes refer to simply as preferences) are grouped in categories, such as Personal, Hardware, Internet & Wireless, and System. If you've added third-party preference panes, they will appear under the Other heading.

The Personal system preferences focus largely on the look and feel of the Mac OS in addition to security settings. Hardware preferences relate to, well, your Mac's hardware as well as peripherals. Internet & Wireless includes preferences for Internet and network connections, as well as Wi-Fi and Bluetooth settings plus a Sharing preference for choosing what services your Mac will and won't share with other computers. Finally, System is a category that Apple created seemingly to throw together preferences that didn't fit in Personal, Hardware, or Internet & Wireless.

We'll start with the General and Desktop & Screen Saver preferences that appear under the Personal heading.


The General preference consists of four sections. The first governs the look of buttons, menus, windows, text highlights, and sidebar size.

Colors and icons: The Appearance pop-up menu lets you choose the color of buttons, menus, and windows. Regrettably, you have just two choices: Blue and Graphite. You'll see these colors reflected in active buttons (meaning the colored-in buttons that you can activate by pressing the Mac's Return key), menu title backgrounds, and selected window headers (Name, Date Modified, and Size, for example).

When you highlight text, that highlighting is blue by default. If blue makes you blue, click the 'Highlight color' pop-up menu and choose a different hue. If you choose Other, you will meet--perhaps for the first time--the Mac's Colors window.

Here you can select colors from a color wheel, play with color sliders, choose colors from a variety of palettes, select colors from a spectrum display, and, my favorite, pick a color from a box of virtual crayons. (Click some of the colors to learn their Crayola-inspired names.) Additionally, if you click the Magnifying Glass icon, your Mac's pointer turns into exactly that. You can then hover that icon over anything displayed on your Mac and, with a click, choose the color of whatever the pointer is zeroed in on.

The 'Sidebar icon size' pop-up menu is self-explanatory. Choose from Small, Medium, and Large sizes for the icons that appear in Finder windows' sidebars.

Scrollbars: If you're new to the Mac with Lion or Mountain Lion, you may not be aware that at one time the Mac's scrollbars were always visible. They contained not only blue bars (called thumbs) that you could drag up and down to scroll through a window, but also small arrow buttons that caused the window to scroll in small increments with each click. Those arrow buttons are gone, as are the blue thumbs, though scrollbars remain.

Those scrollbars now display gray thumbs--sometimes. And the sometimes is what counts in the 'Show scroll bars' setting. If you enable the first option--'Automatically based on mouse or trackpad'--the scrollbars will always show when you use a mouse with your Mac. This is the Always item that you see in the list of options. If you use a trackpad instead, scrollbars will show only when you place your pointer within a window that should show scrollbars, and manipulate the trackpad. Do this, and the scrollbars appear and then fade away once you stop dinking around with the trackpad. This is the 'When scrolling' option that appears above the Always option.

One advantage of choosing the Always option is that you can easily click and drag a scrollbar's thumb to rapidly scroll through a window. Also, thumbs are sized proportionally to the number of items in a window. For instance, if all the objects in a window are showing, you'll see no thumb on the right side of the window because you have nowhere to scroll to. (You may see a thumb on the bottom of the window, however, because you can scroll to the right to see more information about the files within the window.) If a window has hundreds of items, you'll see a small thumb, which indicates that you can scroll the window quite a bit before you reach the end.

You can also configure the behavior of the scrollbar when you click in it. The default setting is to jump to the next page when you click anywhere in the scrollbar. Optionally, you can configure it to jump to the spot that you clicked. You might like this option if, for example, you routinely work on long, multipage documents, and you want to move to the beginning, middle, or end of your documents with a single click.

Saving and such: Mountain Lion, like Lion before it, has an AutoSave feature, which (in supported applications) will automatically save your changes as you work. Some people found that they didn't care for this feature as they didn't want to save the last changes they made before closing a document. When enabled, the first option in this area--'Ask to keep changes when closing documents'--causes a dialog box to appear when you close a document, asking whether you'd like to keep your changes. If you choose not to, the next time you open the document the last version you elected to save is the one that appears (versus the last autosaved version).

The 'Close windows when quitting an application' option addresses another complaint that some people had with Lion: When you restarted an application, all open documents and windows were restored when you next launched the application. Much of the time people want to start fresh rather than with a desktop cluttered with old document windows, and enabling this option makes that possible.

The 'Recent items' pop-up menu is here for no apparent good reason, but it allows you to choose the number of recent documents, applications, and servers that show up when you select the Recent Items command in the Apple menu. Your choices are None, 5, 10, 15, 20, 30, and 50.

Font smoothing: The Mac can smooth the look of fonts using a technology called antialiasing. With the 'Use LCD font smoothing when available' option on, fonts of medium and large point sizes will look smoother.

However, smaller font sizes can be harder to read if antialiasing is turned on. And that's where the second item in this area comes in. If you find small text difficult to read, turning off antialiasing for just those small sizes can help make the text more legible. It's within the 'Turn off text smoothing for font sizes x and smaller' pop-up menu that you choose the point size at (and below) which antialiasing is not applied.

Desktop & Screen Saver

The Desktop & Screen Saver preference, as the name suggests, controls two of the more visual functions of the Mac OS. The first is the pattern (called wallpaper in the Windows world) applied to the Mac's desktop. The second is what the Mac displays when you initiate the Mac's screensaver. First, the Desktop tab.


Lovely as the picture of the galaxy that adorns your Mac's desktop by default may be, some people find contemplating such vastness unnerving. Thankfully there's no need to remind yourself of just how inconsequential your existence is in comparison with such massive and ancient mechanisms. Just select the Desktop & Screen Saver preference, click the Desktop tab, and choose the Desktop Pictures folder that appears on the left side of the window under the Apple heading. To the right you'll see a collection of lovely Apple-supplied images. As you select an image, the desktop's picture changes and a larger thumbnail of the image appears near the window's top-left corner. (Tip: You can drag this thumbnail to the desktop to make a copy of the full-size image.)

If you find the beauty of the images too distracting, select Solid Colors instead and choose one of the default ten colors. If you like the idea of a solid color, but you're not fond of the hues Apple offers, click the Custom Color button to see your old friend the Colors window.

You can also pick images from your iPhoto library and, by default, from the Pictures folder within your user account. (If you've installed a copy of Apple's Aperture photo-editing application, you'll see an Aperture entry as well.) Click the + (plus) button, and you can use the resulting sheet to navigate to a folder of your choosing. Select the folder in this preference pane, and any compatible images it contains appear to the right.

When you select an iPhoto item or folder, a pop-up menu appears just above the image previews. It's within this pop-up that you choose how images display as the desktop pattern: Fill Screen, Fit to Screen, Stretch to Fill Screen, Center, and Tile. Fill Screen does exactly that, zooming the image so that it occupies the screen without distortion. Fit to Screen displays the entire image--and where that image doesn't cover the desktop, a background color of your choosing appears on either side of it. Stretch to Fill Screen stretches the full image so that it covers the desktop. Center places the center of the image smack-dab in the middle of the screen, and may cut off its edges. And Tile takes multiple instances of small images and repeats them in a grid.

Underneath you'll see three options. The first, 'Change picture', gives the Mac permission to change the desktop pattern every so often--when logging in, when waking from sleep, and at intervals of 5 seconds, 1 minute, 5 minutes, 15 minutes, 30 minutes, 1 hour, or every day. If you enable this option, the second option, 'Random order', becomes active. Switch it on, and the Mac will randomly pick an image. Otherwise, images will change in the order in which they're displayed.

Finally, Mountain Lion, as did Lion, makes the menu bar translucent so that you can see a bit of a desktop's image behind it. If you have a particularly busy desktop pattern, you may find this translucence distracting; if so, just disable this option to turn the menu bar an opaque off-white.

Screen Saver

And then there's the Screen Saver tab. Before I delve into its mysteries, a little background.

In the days when Macs weren't as thin as the worst sort of fashion model, users viewed the Mac interface through CRT (cathode ray tube) monitors--akin to the large picture-tube-bearing televisions of the time. These monitors were prone to a condition called screen burn-in: The phosphor inside the CRT could permanently take on an image when that image was projected to it for months on end--the image of the Mac's menu bar, for example, was commonly burned in. The burn-in left ghost images on the display that were distracting.

To help prevent burn-in, companies created screensavers--applications that would automatically kick in after a period of computer inactivity and display moving images rather than static ones. After Dark's Flying Toasters was the most well-known of these products.

Since today's monitors don't suffer from this kind of burn-in, screensavers often serve as an amusement rather than as a prophylactic measure (though they have a practical use that I'll address shortly).

When you click the Screen Saver tab, you'll see that Mountain Lion's screensavers are broadly arranged in two categories: slideshows and screensavers. In the Slideshows area, you'll find 14 slideshow effects. These can show images from a variety of sources, including your iPhoto and Aperture libraries, images from National Geographic, images supplied by Apple, and a folder or photo library of your choosing. You pick the source from the aptly named Source pop-up menu.

Below the slideshow area are Mountain Lion's screensavers. These include three computer-generated patterns, a message of your choosing, album covers from your iTunes library, and a "Word of the Day" that travels across your screen along with its definition. Choose Random, and the screensaver will be one of the six alternatives chosen at the OS's whim. Some of the screensavers have options that you can explore by clicking the Screen Saver area's Options button.

To test the look of a slideshow or screensaver, select it on the left side of the window, hover your pointer over its image on the right side of the window, and click the Preview button that appears. The slideshow or screen saver will expand to full screen. To stop it, just click anywhere.

At the bottom of the window, you'll see a few additional options. The first is 'Start after'. This is where you choose the period of inactivity (meaning you haven't touched the mouse, trackpad, or keyboard) after which the slideshow or screensaver begins. You have choices from 1 minute to 1 hour. The next option, 'Show with clock', displays a clock over the screensaver when enabled.

About Hot Corners

The last option, Hot Corners, deserves a bit more explanation. When you click this button, a sheet will appear that shows four pop-up menus corresponding to the four corners of your Mac's display. Click one of these menus, and you see several commands: Start Screen Saver, Disable Screen Saver, Mission Control, Application Windows, Desktop, Dashboard, Notification Center, Launchpad, Put Display to Sleep, and a dash, which indicates "Don't Do Anything, Thank You Very Much."

You assign these commands to the various corners of your display. For example, you might assign Start Screen Saver to the top-left corner. Do that and click OK; when you drag your pointer to this location on the screen, the screensaver kicks in. Move your pointer, and the screensaver disappears. In short, it's a quick way to invoke one of these commands.

Before committing to a hot corner, examine how you use your Mac. If you often drag your pointer to the bottom-left corner to access the Dock, assigning a command to that hot corner probably isn't such a hot idea, as your Mac will do something that you didn't intend. Rather, place that command in a corner that you'd touch for only that specific purpose.

Screensavers and security

Earlier I mentioned that screensavers serve little useful purpose, and I promised to show a hidden talent. You'll find that talent in the Security & Privacy system preference. Select that preference and then click the General tab if it's not already selected. Click the lock icon at the bottom of the window and enter your username and password. The option you're looking for is 'Require password [some amount of time] after sleep or screen saver begins'. Configure its pop-up menu to read immediately. Now, when your Mac goes to sleep, you invoke the screensaver, or the screensaver starts on its own, and you'll be required to enter your account password before you can use your Mac.

This is a particularly useful option to enable if your Mac is in a location where other people can access it--your office, say, or within reach of a surly teenager. Just shove your pointer into the appropriate hot corner, and you can step away without fear that someone without your password can muck with your Mac.

Next week: About Mission Control