UserDoc:How AmigaOS Works

As we have described, AmigaOS was a pironeer in the early days of personal computing in delivering sophistication that contemporary systems could only have dreamt of and pretended to offer. Today, AmigaOS continues to offer an straightforward elegance that seems to be overlooked in the development of other platforms.

In this page we will explore how your AmigaOS system works.

• Multitasking ?
• Applications
• Parallel Interfaces
• File Storage
• Scripting and Messaging
• System Startup

AmigaDOS: the underlying system

Many beginners are rather confused by the differences between the terms "AmigaDOS" and "Shell". Some people think they just use the Shell or they are just using AmigaDOS commands in a shell window.

DOS was originally an acronym for "Disk Operating System". Some say it should be "Disk Based Operating System" as it does a lot more than operate a disk and that it was really an operating system based (stored) on disks. Some say it should be "Device Operating System". The "Shell" is really a text-based window into AmigaDOS and the commands that run there.

The whole AmigaDOS system includes things such as:

• A set of commands that can be used in the Shell window and elsewhere.
• A system for saving data to disk and retrieving it from disk.
• A system for filing data on disks.
• An interface for peripherals such as keyboards, monitors, printers, etc.
• A method of running programs
• A multitasking system for running more than one program at a time.
• etc. etc. etc.

Read the AmigaDOS manual to understand and learn everything about AmigaDOS.

How is my data stored?

Files

Executable files

Programs you can start are stored in executable files. These are files with an executable bit, a flag that shows AmigaOS that such file will do something when started. An example is a music player. When you start this executable, the player opens and you can start playing music files.

AmigaOS can run two different kinds of executable files: the AmigaOS native programs made for the PowerPC processor and programs created for the Motorola 68k processors. The laters are executed inside an emulation that transcripts them into PowerPC code.

Data files

Files that are not executable are data files. These contain some data that will be manipulated by programs. Some examples are a music file, a video file or a text document.

Directories/Drawers

In order to organise things a bit, files are not all of them in the same place. We create directories which like drawers of a cabinet will store different files of the same kind. The graphical interface of AmigaOS being called the Workbench, directories are often called drawers.

Disks, partitions and volumes

Disks

Disks are storage medium you can purchase on a computer store. We use them to store our files. They can be internal hard disks, external ones or a USB disk drive.

Partitions

A disk is often very big and many users prefer to make it more organised. This is done virtually splitting the disk into several smaller parts. This operation is known as creating partitions on a disk.

TODO: insert a disk image with partitions

Volumes

A partition is a physical area on a disk. To access it with AmigaOS we could read the physical data off the partition but it's not an easy way. To make it easier AmigaOS uses the concept of volumes. These are virtual representations of a partition. The volumes have a name so AmigaOS and therefore the user can access all files/directories stored on it in a very practical way: just by using its name.