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AmigaOS

AmigaOS is the default native operating system of the Amiga. The DOS library and CLI was based on a Tripos port by MetaComCo written in BCPL.

It has:

It always came divided in two parts:

Amiga 1000 asking the user to insert the kickstart disk.

Kickstart is the name given to the bootstrap ROM. On the original Amiga (the Amiga 1000), this was loaded from disk, although later Kickstarts were on a ROM chip inside the computer. The Amiga 1000 could be modified to take these chips.

As well as containing the code needed to boot the computer, the Kickstart also contained large portions of the Amiga's operating system, such as Intuition (the Amiga's graphical user interface libraries), Exec (the multitasking kernel), Dos (the disk handling libraries).

Later versions of the kickstart contained drivers for IDE and SCSI controllers, PCMCIA ports and various other hardware that came with Amigas.

With third party hardware, it is possible to have two or more versions of kickstart in a single machine, selectable either by a switch or a keyboard shortcut when you first turn the machine on.

With third party software, it is possible to have a different kickstart loaded in RAM and to use it instead of the ROM one - for example Kickstart 1.3 may be loaded in order to run old games incompatible with Kickstart 2.0 and higher. These programs are called Softkickers.

Workbench is the native graphical user interface for the Amiga computer. As the name suggests, the metaphor of a workbench, rather than a desktop, is used. Directories are depicted as drawers, executable files are depicted as tools, data files are depicted as projects and GUI widgets are gadgets. Most Amiga application software has pull-down menus starting "Project Edit ..." rather than the "File Edit ..." typical on other platforms.

In many other respects the interface resembles Mac OS, with the main desktop having the drive icons, and a single menu bar at the very top of the screen. Unlike the Mac mouse, the Amiga mouse has two buttons - the right mouse button operates the pull-down menus, with a Macintosh-style 'release to select' mechanism.

A unique feature of Workbench is multiple screens. These are somewhat similar to X Windows virtual desktops, but are generated dynamically by application programs as necessary. Each screen can have a different resolution and colour depth. A gadget in the top-right corner of the screen allows screens to be cycled - as the OS stores all screens in memory simultaneously, redrawing is instantaneous. Screens can also be dragged up and down by their title bars.

Although, strictly speaking, Workbench is only the file-management part of AmigaOS, it is a commonly used term to refer to all the parts of the OS that do not reside in the Kickstart ROM.

The Workbench environment is not required for the machine to function, therefore a lot of old games boot directly from Kickstart, without loading it.

Without Workbench there is more RAM available, however the application will lose the ability to multitask with other applications. In this circumstance, the machine must be rebooted.

Each Kickstart version is tied to a particular version of the Amigas operating system software, so you should only boot Workbench 1.3 on a machine with a 1.3 Kickstart ROM. It is possible to boot incorrect versions (Workbench 3.1 will boot on Kickstart 3.0, with some problems). The only exception is Workbench 2.1, which was a software-only update based on Kickstart 2.04. Also, the latest Workbench versions, 3.5 and 3.9, use Kickstart 3.1 and load ROM updates at boot time.

AmigaOS versions

This is the original implementation of AmigaOS. It had a distinctive blue and orange colour scheme. Versions after 1.0 consisted mostly of bug fixes. 1.x shipped with the A1000, A500, A1500, CDTV and A2000.

This was a beta version of the upcoming 2.0 update, but was released in very small quantities with early Amiga 3000 computers.

2.0 introduced a lot of major advances to the Amiga operating system. Gone was the harsh blue and orange colourscheme, replaced with a much easier on the eye grey and light blue. The Workbench was no longer tied to the 640x256 (PAL) or 640x200 (NTSC) display modes, and much of the system was improved with an eye to making future expansion easier.

Unfortunately, 2.x introduced some incompatibilities with old, badly written software, and so a lot of people were upset with this update.

2.x shipped with the A500+, A600, A3000 and A3000T.

3.x was another major update. Updates included:

3.x shipped with the CD32, A1200, A4000 and A4000T.

After the demise of Commodore, the later owners of the Amiga trademark granted a license to a German company called Haage & Partner to update the Amiga's operating system. Along with this update came a change in the way people referred to the Amiga's operating system. Rather than specifying "Kickstart" or "Workbench", the updates were most often referred to as simply "AmigaOS".

Updates included:

Supplied with TCP/IP stack, web browser, and e-mail client.
Improved GUI, called "ReAction"
AVI/MPEG movie player
Support for hard disks larger than 4Gb (a limitation from 1.x)
HTML documentation
MP3 and CD audio player (OS3.9)
Dock program
Improved workbench

  • AmigaOS 4

    • A new version of AmigaOS 4 is being developed by Hyperion Entertainment under license for Amiga, Inc. It is a major update, comparable to the leap from Windows 3.1 to 95, or MacOS 9 to X.

    The new version will be PowerPC native instead of 680x0, and feature many updates. It is the first version to finally completely remove the Tripos legacy code.

    AmigaOS 4 will run on Amiga 4000 computers with PowerPC upgrade boards, and the new AmigaOne systems.

    Some of the features promised for 4.0:

    Greatly enhanced GUI
    Virtual memory
    Limited memory protection
    CD/DVD writer support, including Mt. Rainer
    Integrated GDB debugger
    Included PDF viewer
    Enhanced shared library model
    Support for PowerPC (native) and 68k (emulated) applications
    Improved input device support
    Support for modern hardware devices

    Although not strictly Amiga related, a recent fork of FreeBSD-4.8 called DragonFlyBSD has been created by a former FreeBSD developer and Amiga programmer Matt Dillon. DragonFlyBSD (although still a work in progress) aims to make the BSD core more like the Amiga architectually, featuring a message-passing kernel, allowing for a very efficient and virtually mutex free SMP design.

    External Links

    See also: AROS, MorphOS, Guru Meditation