Snow Leopard: Do I need Rosetta?

One of the least-understood things about Snow Leopard is its dropping of support for PowerPC processor-based Macs. Let's take a quick look at the issue.

First of all, let's divide PowerPC into its two components, hardware and software.


Over the life of Macintosh computers, there have been three different chip types.

The first Macs used Motorola 680x0 chips. They are also called 68K Macs. These chips were used in the Compact Macs, the Macintosh II series, the Macintosh LCs, 500s, Centris, Quadra, and Performa computer with 3 digit names, and early PowerBook computers. Apple discontinued using this chip in 1996. Mac OS 8.1 was the last operating system that could run on 68K Macs.

The Motorola PowerPC was the next processor line to be used. They were used in a wide variety of computers with these chips were produced from 1996 until August 2006.

Apple introduced the first Intel chip based Mac, the Mac Pro in August of 2006. This line of processors is still in use today and it will be used for the future.

It is the PowerPC (and 68K) hardware that cannot use Mac OS X 10.6 Snow Leopard.


The other use of PowerPC is its programming code. It is included in many of the applications that you are using on your Mac today. That element of PowerPC is not being dropped in Snow Leopard

When Mac OS X 10.0 was released in March of 2001, Apple included the Classic evironment, – translation software, that allows applications that were compiled for Mac OS 9 to run in Mac OS X. That feature was available until Mac OS X 10.5 Leopard was introduced in March of 2005.

When the Apple moved to the Intel processor from the PowerPC they introduced Rosetta which allowed code written for the PowerPC processor to be run on Intel processors. Although we do not expect Rosetta to be around forever, there are many applications that are still being used that contain PowerPC code. One group of applications that comes to mind is the Adobe CS3 suite. Another is AppleWorks, and still another is Quicken 2006.

How can you tell what kind of applications you have on your computer? The easiest was is to use the System Profiler. The easiest way to get to it is through the More Info… button in About this Mac:

It will look something like this when you open it:

Locate Applications in the left column and click on it:

Notice the scroll bar indicates that there is a lot of the window that is hidden. Use the re-size tab in the lower right corner to drag the window until it is much wider:

You can change the size of columns by dragging on the line in the column header:

You can change the order of columns by clicking on the column title and dragging it to a new location:

You can change the sort by clicking a different column:

You can change the sort order by clicking the small arrow at the right end of the column:

Taking a look at my list of applications, you can see that I have several different types:

My Quicken 2006 is really old in software age. Parts of it will even run on a 68K Mac! I need to replace it, but I am waiting on Intuit to release a new version of Quicken (hopefully Quicken 2010) soon!

Many of my PowerPC applications are parts of Adobe CS3, which I will retire when Adobe CS5 is released. However, scrolling through the list, I have found a number of applications that I will be deleting. Do this cautiously! Make sure that the item you are deleting is a stand-alone application--that is not a part of something like the Adobe CS3 suite!

PowerPC applications run in Rosetta.

Still another kind of application is Universal. These applications contain code to run on both PowerPC Macs and Intel Macs.

These applications include both PowerPC and Intel versions of the code. When a x is present in their Get Info window, tney rely on the Rosetta software. If you have an Intel Mac, you do not want to be running apps using Rosetta.

The last kind of application is Intel. These will only run on Intel Macs. Many of these applications were added when I upgraded to Mac OS X 10.6 Snow Leopard. These may be are smaller (because they do not contain the code for PowerPC) and many are much faster because they run in 64 bit mode. (I will talk about this in a future blog entry.):

So, do you have to get rid of Classic or PowerPC applications? Not necessarily. My Classic version of Quicken is hidden deep inside the Quicken 2006 package. If I remove it, I might break my ability to run Quicken 2006, so I plan to just leave it alone. I have plenty of room on my hard drive and it takes up only 10.7 MB. The slash through it means that it will not launch on my Intel Mac:

I will be keeping an eye on my PowerPC and Universal applications to see if they have been updated. Over time, developers will release newer versions without the PowerPC code. They will be smaller and they should run faster.

However, in my quest to improve my computer usage, I frequently ask myself--

Am I spending my time working on my computer -- or with my computer?

I have noticed that many computer users spend most of their time tweaking the little things while photos, blogs, movies, email and even work are pushed to the side. Someday all of us will stop using our computers. What will be your legacy? I hope mine includes memoirs, photo albums, movies and projects to pass on to my children and grandchildren! They won't really care how clean or fast my computer was!

If you need some help with your computer -- or help learning to do new things, consider booking a tutorial session with me at Dr. Mac Consulting. The cost is $60 per hour and we will cover just what you want to learn. Give us a call at 408 627-7577 or send us a message at


blog comments powered by Disqus