System Software
Disk structure | Directory (Structure | Multilevel)

Disk directory structure

Operating systems are required to store user files physically on the disk and display them to the user in logical way.

Disk Structure

To help you understand how the computer stores data on a disk, let us first look at a Hotel room booking system;

If you were part of a large group and booked into a hotel, some of the following things might happen;

The hotel would keep a register of where all the guests were staying

A group might be put in rooms next to each other, or if rooms were already taken, might be scattered throughout the hotel.

To find out were the group was staying, you would look into the guest register.

This is similar to the way a computer stores data on a disk;

Physical data organisation

Directory Structure

	To help you understand how the computer allows us to manage data on a disk, let us first look at how a farmer could arrange their animals.
	First the Farm is made up of boundaries, limiting how many animals can fit onto the property.
	Next we put a house on it and create a home paddock. Note that the animals can live in the home paddock
	Since we don't want the animals around the house we put them in their own paddocks. We would also give the paddocks names, such as the Large paddock, or the cow paddock.

This is similar to the way the computer allows you to manage your files on the disk. (right through to buying a new farm if you have too many animals !!)

Also consider a file box containing folders and loose papers.

swssfdr7.gif (3270 bytes)

Multilevel Directories

Exercise

For your class (or friends) create a diagram of how I would get to them from where you are now.
e.g.. Car to Hastings, Drive to Flaxmere, go toTui St

(You can include other countries in this exercise)

Once completed rewrite to;

swssfdr6.gif (2135 bytes)

When there is more than one user on your computer, or you are using several applications or you are working on several different projects, the number of files in a directory can become large and unwieldy. You may want to keep the files separate, or organise programs into their respective categories.

In an office you separate and organise files into different filing cabinets. The MS-DOS equivalent is putting files into sub-directories.

Diagram: Multilevel Directory Structure (with files)

TREE /a >>lpt1

The full name of each file is given by

<Drive>:<path><filename>.<extension>

So DRCTRL.DAT has a full name of C:\DEBTORS\DRCTRL.DAT
and
MEMO1.TXT = C:\DATA\MEMOS\MEMO1.TXT