How to Add a Second Display to Your Mac

Some tips on getting the job done without pulling out your hair.

Yesterday, I had the pleasure of adding a second display to my 24-in iMac setup. In this quick article, I’ll explain why I did this and provide some tips for how you can do it, too.

Why Two displays?

First of all, you need to understand how having a second display on your computer can work. Basically, you can use the second display two ways:

  • Use the second display to mirror the main display. You’d use this primarily when doing a presentation and you need a larger or second display to display to your audience. This is pretty common if you do a presentation from a laptop; you’d connect it to a projector which acts as a second display, then turn on mirroring.
  • Use the second display to add screen space to your computer setup. So instead of having the space on one display screen, you also have the space from the second display screen. The joined pair of screenshots below illustrate how this could work. This is how I use the second display.

The following example shows how I use my two displays. The one on the left is my 24-inch iMac display. This is my main display, which includes the menu bar, Dock (when displayed), and desktop icons. The one on the right is my new 22-inch Samsung DVI-D display. I’ve positioned them side by side, so when my mouse pointer is on the right side of the left display screen and I move the mouse to the right, it moves into the right display screen.

Two Monitors on a Mac

You may wonder why, with 24 inches of screen real estate set to its highest resolution (1920 x 1200 pixels), I wanted to add another display to my setup. There are two reasons:

  • I could. High resolution digital displays are surprisingly affordable these days (with the exception of those made by Apple and a number of other high-end makers). The new display cost just $309 in Best Buy; and yes, I’m sure I could have gotten a better deal elsewhere, if I were willing to spend days/weeks/months researching and shopping.
  • I felt that I could be more productive if I could move my online applications — Mail, Twitterrific, Skype, iChat — into a second display where they’d be visible but I wouldn’t have to switch to them. (Yes, I’ve tried Spaces and I’m very sorry to say that I just couldn’t make it work the way I needed it to with all my apps.)

I would like to mention here that although I bought a Samsung display and it works fine with my iMac, I’m not necessarily recommending it. The picture is okay and it worked right out of the box without installing any drivers. But the picture quality is not anywhere near as good as the incredible picture on my iMac — even my husband commented on it at first glance. So if you work with graphics or have problems with your eyesight and you’re not on a budget, I recommend that you check out an Apple display first. It might just be worth the $900 (for 23 inches) or $1800 (for 30 inches) price tag for you. Personally, I couldn’t justify the additional expense.

Set Up Tips

Once you decide to add a second display, consider these things:

  • Can your computer support a second display? This is a biggie. If the answer is no, forget it. You can find out if your Mac can support a second display by visiting the Apple store and chatting with someone working the floor. If that’s not an option, try checking Apple’s Web site for technical specifications on your computer model. (Here’s the specs for mine.) If you’re really confused and your Mac is a currently available model, you can try giving the Apple Store a call at 1-800-MY-APPLE (in the U.S.) and asking. (Please don’t use this phone number to get technical support — it’s a sales number and the person who answers will not be able to help you.)
  • What’s the maximum resolution your computer will support for the second display? This is also information you can get from the above sources. You need to know this so you don’t buy a display that’s too big for what your computer can support. My 22-inch Samsung has a lower resolution than what my computer can support.
  • What cable will you need for your display? Before you answer this question, either know which display you plan to buy or buy the display. If you’re like me, no matter how many cables and adapters you have in your home or office, you will not have the one you need.

To make sure I got the right adapter, I looked at the description on the display box, examined the DVI-D cable that came with the display, checked the pictures here, called the Apple Store to ask, and looked up the adapter on the Apple Store’s Web site.

Do I sound paranoid? I live 50 miles from the closest Apple Store and there’s nothing more frustrating than getting the wrong cable or adapter. The Apple Web site is full of bad reviews by buyers who bought the wrong adapter; I didn’t want to make the same mistake.

I sent a link to the Apple Store Web page for the adapter to my husband at work in Phoenix and told him to print it and bring it with him to the Apple Store. He walked into the Biltmore store, flashed the printout, and got the right adapter. The cost: $19.

Remember that the adapter I bought works for me with my computer and my second display; it might not work for you. Do your homework and don’t blame me if you buy the wrong one.

Setting Options

Once you’ve got the second display connected and powered up, your Mac should automatically recognize it. Although you may not need to configure it at all, you can. Here’s what the configuration looks like with my Leopard setup.

Open System Preferences and click the Displays icon. Two Displays preferences panes should appear — one on each screen.

iMac Display PanelSamsung Display PanelHere’s the Display panel of the Display preferences pane on each display. I won’t go into detail on the usual settings; I cover all that in my Leopard book. Instead, note the Gather Windows button. Clicking this button moves all the open windows to that display. You might find this handy if you have a second display connected and you don’t want to power it up. What I’ve discovered is that your Mac will remember where an application’s windows were the last time you ran the application and will reopen the windows there. The Gather Windows button moves those windows to the display you click the button on.

You might also notice a Rotate button on the SyncMaster window for my Samsung display. That’s a weird little feature that enables me to rotate the display’s image in 90° increments. (The larger display actually has a rotating base.)

Display ArrangementTo set up the positioning of the displays, click the Arrangement button on the main display’s Display preferences pane. The Arrangement panel, shown here, displays the two displays as they are arranged. In my setup, the two displays are physically side by side with the Samsung a little lower than the iMac. You can drag the boxes to reposition the displays and I highly recommend that you do so if you need to. For example, if your second display is on the left, drag its box to the left of the main display. This way the mouse behaves logically when you drag it from one screen to another. (This, by the way, would be a great practical joke to play on a friend with two displays; just switch the boxes around to drive him nuts!)

If you decide you want the menu bar on the other display, just drag it over there. That’ll move the menu bar, Dock, and volume icons that appear on the desktop.

If you want to mirror the displays, as discussed at the beginning of this article, turn on the Mirror Displays check box. This is also where you’d disable this feature if it happened to be turned on by default.

But Wait! There’s More!

Displays MenuOf course, you can set many of the Options in the Displays preferences pane if you turn on the Displays menu. Here’s what my Displays menu looks like with both displays connected. As you can see, I can enable/disable mirroring, set resolution for either display, or open Display preferences. Saves the bother of going into the Displays preferences pane for making minor adjustments.

Learn More

Product ImageYou can learn more about options in the Displays preferences pane on pages 553-554 of Mac OS X 10.5 Leopard: Visual QuickStart Guide.

And if you’d prefer to stick with one monitor, be sure to check out pages 179-183 of the book to learn more about Spaces.

Leopard 10.5.2 Adds More Support for Routers

Makes Back to My Mac feature accessible to more Leopard users.

The release notes for the Mac OS X 10.5.2 update mentions, almost in passing, that the update “adds support for more third-party routers” for the Back to My Mac feature. It then provides a link to a support document titled, ” Back to My Mac: Supported router devices (Mac OS X 10.5).”

Back To My MacThe article indicates that Back to My Mac should work with all AirPort Express and AirPort Extreme base stations. It provides additional links to information for configuring a base station to work with Back to My Mac.

The article also lists third-party manufacturers whose routers work with Back to My Mac.

If you’re struggling to get Back to My Mac working on your setup, the support document is a good place to start your troubleshooting process.

Page References

Product ImageYou can learn more about enabling the Back to My Mac feature of Mac OS X on page 460 of Mac OS X 10.5 Leopard: Visual QuickStart Guide.

You can also find more detailed how-to information in an article I wrote for Peachpit Press’s Web site, “Going Back to Your Mac in Mac OS X Leopard.”

Toggling Menu Bar Translucency

Your Leopard menu bar no longer has to be translucent.

One of the things some Leopard users complained about on the initial release of Leopard was the translucent menu bar. Rather than appear at the top of the screen like a plain white (or gray) bar, it now showed the desktop image through it. People with extremely “busy” desktop images found it difficult to read the menu bar.

Menu Bar
Here’s an example of the standard, translucent menu bar with the Bamboo Grove desktop picture. I don’t think it looks so bad.

(I kind of like the way the translucent menu bar looks. But then again, I don’t like “busy” desktop images.)

Desktop PanelIn Mac OS X 10.5.2, the recent Leopard update, Apple added a new setting in the Desktop panel of the Desktop & Screen Saver preferences pane: Translucent Menu Bar. Turning this check box off removes menu bar translucency, returning the menu bar to a plain gray, Tiger-like menu bar.

Menu Bar
Here’s what the same menu looks like with the Translucent Menu Bar option turned off.

Oh, and you may not have noticed this at all, but the menus, which are also translucent, are now a little less translucent than they were in the original Leopard release.

Page References

Product ImageYou can learn more about setting Desktop options on pages 166-167 of Mac OS X 10.5 Leopard: Visual QuickStart Guide.

Using Leopard’s Mosaic Screen Saver

A very cool screen saver for folks with a lot of photos stored on their Macs.

One of the very cool and almost hidden features of Mac OS X 10.5′s improved screen saver is the photo mosaic screen saver module. This screen saver tells your computer to use all of the photos stored on it to create mosaic images of photos stored in a specific folder or an iPhoto event or album.

If that description doesn’t really help you visualize what this screen saver is doing, this post includes a video that not only shows you how to set it up, but it shows you the screen saver in action.

Keep in mind that the mosaic screen saver works best if you have a lot of photos in your iPhoto file.

Setting It Up

Here are the step-by-step instructions for setting up this screen saver on your Mac. These instructions are repeated in the video, but you might want to read through them quickly to get an idea of what to expect.

  1. Choose Apple > System Preferences.
  2. In the System Preferences window that appears, click the Desktop & Screen Saver Icon.
  3. In the Desktop & Screen Saver preferences pane, click the Screen Saver button.
  4. In the Screen Savers list on the left side of the window, scroll down to the Pictures list and select one of the picture folders, iPhoto events, or iPhoto albums in the list. This will be the folder full of images that are created with the mosaic tiles.
  5. Under the Preview area, click the Mosaic Display Style button.
    Screen Saver
  6. Screen Saver OptionsClick the Options button and use the dialog sheet that appears to set options, including whether slides should be presented in a random order, how many rows of mosaic tiles should make up the image, and the speed at which the mosaic image should be built. Click OK to save your settings.
  7. Set screen saver Start options as desired, using the slider in the main Screen Saver window.
  8. To see what your screen saver will look like on a full screen, click Test. (You can press Esc when you’re finished previewing.
  9. Click the Desktop & Screen Saver preferences window to save your settings.

Seeing It In Action

Okay, here’s my home movie of the setup process, as well as a full-screen test with a number of images. To keep the video small, I downsized my computer display’s resolution. You’ll need QuickTime installed on your computer to see this video.

Two quick notes about this video:

  • To make the file size smaller, I’ve set the screen rate a bit low for this. As a result, the screen saver’s transition appear a bit jerky. When you use the screen saver, you’ll see that the transitions are actually quite smooth.
  • This is a 17 MB file. The quickTime controller may not appear immediately after you click, especially if you have a slow connection to the Internet.

[Note: I removed the full-size video I'd linked to here in addition to showing the movie above. It was choking at least one offline RSS reader with its 72+ MB size.]

Page References

Product ImageMac OS X 10.5 Leopard: Visual QuickStart Guide includes more information about related topics:

  • Screen Saver, pages 166-169
  • Using System Preferences Panes, pages 547-549
  • Preview, pages 304-308

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Choosing Your Mac OS Startup Disk on the Fly

For folks who have two operating systems installed on their computer.

My “test mule” these days is a MacBook Pro. (I use the term “test mule” to identify the computer I use to run software on when I’m writing books and articles.) In preparation for writing a book about Leopard while I still had to work with Tiger for articles and blog posts, I partitioned the hard disk and installed both operating systems, one on each partition.

Startup DiskThere are two ways (at least) of choosing a startup disk. The most obvious is with the Startup Disk preferences pane, which is shown here. It should display all system folders the computer can boot from, including any inserted CDs or DVDs. You choose a folder and click Restart. Easy.

The trouble with this method is that your computer needs to be running to open the Startup Disk preferences pane. What happens if your computer is shut off and you decide you want to start with the other operating system — the one that wasn’t selected when you shut down?

The answer is the Option key.

Start the computer and hold down the Option key. Before the operating system loads, your computer will display icons for each disk the computer can start from. Release the Option key and click the disk you want to start from to select it. Then click the arrow beneath it. The startup process continues from that disk.

One important thing to keep in mind here is that the change in startup disks is for that session only. If you always want to start from that operating system from that point forward — or at least for the next start — you should use the Startup Disk preferences pane to make that selection.