By Jeff Steele
| Jeff is a freelance designer, writer and overall web junkie. He has an Associates degree in Computer Graphics and Animation and teaches at a local college. After spending nearly 13 years in the printing industry, he now works in the software industry and is the owner and developer of InternetKnow-How.com. |
All that is required to maintain some semblance of sanity and a full head of hair is a basic understanding of how each platform handles files, what can go wrong, and how to keep it from going wrong.
The most important factor here is knowing how each platform identifies files. If you know that, you have about 90% of the problem behind you. Let's take a quick look at the methods behind the platform madness.
A Mac file actually consists of 2 parts. There's the data fork and the resource fork. The data fork is the main part of the file that actually holds, as you might guess, the file data. The resource fork contains, among other things, two codes that are used to identify files. They are known as the File Type and Creator code. Between these two code, they tell the Mac OS not only what kind of file it is, but what application actually produced it. If you create a .tiff file in Photoshop and another in Corel, the Mac OS uses the creator codes to decide which application to launch when you double-click on the file. That way, you aren't trying to open your Photoshop files with Corel or vice-versa. It really is a beautiful system.
However, it does have a few drawbacks. The main one is that there is no external way to identify a file unless you happen to recognize the icon. To actually see the file type and creator codes you must either view them one at a time using Sherlock or use a utility like DropGetInfo to reveal them. We will discuss the other roadblock in this system in a minute.
On the Windows side, file identification relies on the 3 digit extension that is attached to the file. There is no internal marker within the file to determine what it's content or origin is. The best and the worst thing about this system is that you can change the file type (or at least what type of file the system thinks it is) by simply changing the extension. However, this must be accompanied by a stern warning. Just because you change the file extension does not mean you change the file! In other words,if you have a .tif and you want a .jpg, changing the file extension will not change the actual format of the file. That can only be done in an application that is capable of handling that particular file type.
As with the Mac, there are some rather serious drawbacks to this system. Most notably, if the file extension is missing, there is no way for you to determine what any given file is. Also, since there is no creator-type identification of files, any given format can only be associated with one application. Therefore, if you create a TIFF file in Photoshop and another in Corel, when you double-click on the icon, it will always launch either Photoshop or Corel, whichever application that file type is associated with.
So, you ask, what happens when these oh-so-differently marked files go to their respective darksides?
Related Information 
- Cross-Platform Tips & Tricks
- Converting Images
- Cross-Platform File Naming
- Mac-Windows Integration
- Graphics File Formats
- Macintosh Cross-Platform Software
- PC and Windows Cross-Platform Software
