The latest version of OSX, due out shortly, does not include Rosetta, software included in past versions to make it possible to run programs written for older versions of the hardware. One result is that Eudora, the Email program which I have been using for almost twenty years and on which I have an enormous collection of past correspondence, will stop working when and if I update the operating system. The obvious solution is to move all of my accumulated email to a more up to date email program, probably Thunderbird. So far my attempts to do so have been unsuccessful—mailboxes copy over, but their content does not. Until I can solve that problem, I do not plan to update to Lion.
There is, however, another and more elegant way in which the problem could be solved. While I cannot run a program that worked under OSX10.2 but broke under 10.3, I can and occasionally do run programs under OS9, using a free third party emulator and Apple system software to which I have a license based on my ownership of the long obsolete machine it originally ran on.
What open source volunteers did for SheepShaver
, Apple programmers, with vastly greater resources and unlimited access to Apple's own past software, could surely do better. Emulation is a well developed technology; I can switch among the current version of OSX, either of two versions of Windows (in Parallels), or OS9 in Sheepshaver, without ever having to reboot my machine. It is true that emulation carries some penalty in speed—but I would expect that to be more than outweighed by running software designed for machines of five or ten years ago on current hardware. Maintaining, in effect, multiple copies of Apple's system software on one machine would tie up a certain amount of hard drive storage—but modern machines have very large hard drives.
Apple's current approach to backup is an elegant program named Time Machine. Instead of giving you a backup of your hard drive as it was at some point in the past, it gives what its name implies, access to the state of your drive as it existed a day ago, a week ago, a month ago. That could be very convenient when you discover that it was last month that you accidentally deleted a document you now need or made changes you would now like to undo.
What I am proposing is the OS equivalent. Most users most of the time would be running the latest version of the operating system. If I want to run Eudora, I enter OS Time Machine, scroll back to OSX 10.6, and am good to go. If I want to entertain myself with Warlords II, a game that I and other members of my family spent quite a lot of time playing a very long time ago, I scroll back to OS9, perhaps even OS8, and play it. If I want to access documents written with WriteNow, my and family's favorite word processor for many years but now many years unsupported, or on AppleWorks, which at the moment still runs on current software but not very well, those too would be easy options. Emulation is not, of course, perfect; their might be occasional glitches. But it ought to be adequate for most purposes.
And very cool.
When I mentioned the idea to my wife, she pointed out a further advantage. Home computers such as the TRS80 and the Apple II first became widely available more than thirty years ago. That means that at this point, there are quite a lot of people in their fifties, some in their sixties or older, who have been routinely using computers for most of their adult life, not even including those who started out earlier on mainframes.
As people get older, they tend to become more conservative. At twenty, learning a new program to do something your old program already does, perhaps do it a little better or with a few more bells and whistles, feels like an adventure, a challenge. At sixty it may feel more like a chore. Once OS Time Machine is incorporated in the Macintosh system software, you never have to do it again. If the new program has new features you want, you buy it and learn it. If the advantages of the new are outweighed by the very large advantage of software you have been using for years and are intimately familiar with, or if the changes actually make the new software less suitable for your purposes than the old, you don't. I expect there are already enough cybergeezers to make up a significant market niche, and the number can only increase.
Over time, OS Time Machine could introduce additional features. Double click on a program that no longer runs on the latest version of the OS, and it automatically shifts you back to the most recent version under which it did run before loading the program.
So far as I can see, the proposal is technically doable, although it would of course cost Apple something in programmer time and other expenses. The strongest argument I can see against it is that it would increase the complexity of the Macintosh software universe by keeping more old programs in use, programs that users might, perhaps unreasonably, expect Apple itself to support, a cost that might more than outweigh the benefits.
But I hope not.