Tips On Computer Technology By: Bill Michling

Welcome back! Last week we talked about saving information from the screen to a file, and also some Internet sites to check out. Since we did not get to talk about the file forks last week, we will talk about them this week. I will also touch upon a simple screen saver that does much more than just dim the screen.

I apologize in advance if I get too technical in this first piece.

** File forks

What is a file fork? Why do we need them? Why did Apple decide to use them? What types are there?

Answers:

Most disk operating systems store a file as one long string of characters. For example the word “bill” is made up of 4 characters or “bytes”, one byte for each character. They would be saved in the order they appear in the word. If you wanted to create another one to save you would need to create another file. Apple created a disk operating system called MFS that included two character sequences or “forks”. In other words when a file is saved it is save as two sequences of characters instead of just one. It is still one file, just two separate and distinct sequences of characters. Apple also included in HFS (Hierarchical File System), the ability to save two forks.

Why have more than one fork anyway? Extra forks are useful when an application wants to store related data into a single file instead of two files or more. For example an application can store data in one fork and font and style information in the other fork.

Apple found out that forks are so useful the latest Apple disk operating system HFS plus allows as many forks as you can fit in the available disk space. The current MacOS does not currently support more than two “forks”, but a future version just might. Can you imagine a word processing file that not only has the final file, but all the versions leading up to the final file! This way you can view any version all the way to the final version. This way you can restore to any version you may need! How about a music sequence. Each fork could hold a track instead of having multiple files for each track….

I am sure the kind of uses for forks will boggle the imagination in the future…..

** Types of forks

OK, we talked about forks in general, what type of forks are there? Since the MacOS only supports two forks at this time, there are two types.

The data fork usually stores what else, all the data.