No fitness for any particular purpose is claimed or implied.
Permission for unlimited duplication and distribution is herewith granted, provided that this notice is distributed unaltered along with the Software. Please read the request for registration at the end of this document.
<- This is the Scroll Bar
In order to scroll upwards, move the mouse into the Scroll Bar next to the line that you wish to move to the top of the window. Then click the mouse button.
Getting started with MacOberon
Oberon is an extensible system. There is no difference between functions offered by the operating system and functions added by a user which enhance the basic system. As a matter of fact, Oberon abandons the notion of a Program altogether. Atomic actions in Oberon are called Commands.
Commands are parameterless procedures which may be executed directly from the operating system interface. Procedures from anywhere in a module hierarchy may be called in this way and there is no need for a "top" module which distributes commands to other modules. Instead, command distribution is built into the operating system. When a command terminates, control is passed back to the operating system's main loop. However, the module that contained the last command remains loaded in the system and all of its global variables remain unaltered. Subsequent commands may reference these variables freely.
The granularity of commands may be quite fine. Typical commands display the directory of a storage device, increase the font size of the text last selected or compile the contents of the active window. A user may execute commands in any sequence and may thus be working on completely different problems in different windows at the same time. We call this "one-process multitasking".
Using Commands
Commands are activated by the use of an Action Button (on the Macintosh, this is the Control key on the keyboard). Pressing the Action Button while pointing at any text anywhere on the screen will try to execute a command of that name. This may be text in a word processor document, captions in a drawing, or even the title string of a window.
The system will then attempt to interpret the text that is pointed at as "Modulename.Commandname" and search for the corresponding module, possibly loading it from disk if it cannot be found in memory. If the module is present or can be loaded, it will then search for the requested command and execute it. If the module or the command cannot be found, the system will simply resume its usual input state (i.e. not display an error message).
For example, the text written in italics following this paragraph is a command that will display the current time in the Log Viewer (the window in the upper right corner). Execute this command by moving the mouse over it and pressing the "control" key on your keyboard:
System.Time
Extensibility
The main feature of Oberon is extensibility. A user can add an arbitrary number of commands to the system at any time simply by writing a module and compiling it. There is no need to install the command (it may be activated as soon as compilation is completed) and modules containing commands are not added to the system until an actual call is made. The <working menus> of commands that users keep (called Tools in Oberon) are regular text documents and freely editable.
Even the basic resources of the system are extensible. For example, the editor you are just using supports "live" extensions of characters which are sent messages when editing operations occur. The moving objects that you see below are such "extensions" of characters. They float in the text just as characters, and may be cut, copied and pasted.
To Probe Further
A lot of documentation is supplied in this distribution. Execute the command below (by pressing and releasing the Command key over it) for viewing a first introduction to the built-in mouse commands and most important basic commands of Oberon:
Leda.Open MacOberonStarter.Doc
We have also prepared a Tool for you that leads you to further documentation about different parts of the system. Please:
Write.SysOpen Documentation.Tool
Portability
Oberon is also available for Ceres, DECStation running ULTRIX, Sun SPARC and IBM R6000 machines. Shortly, there will be a version for Intel 80386 processors running AIX. The Oberon libraries on those machines as well as the document architectures in all implementations are identical. For example, you could open this document on any of the machines mentioned above and see the same moving icon and clocks, despite even the fact that not all of the machines use the same byte ordering
Only the compiler and the low-level-modules Kernel, Macintosh, Modules, Input, Display, Display1, Fonts, Files, Files1, Reals, SCC, Printer, Math, MathL and Oberon contain some machine-specific code. All other modules, including the Leda, Write and Draw application packages and the user interface modules (Texts, Viewers, MenuViewers, TextFrames) were simply recompiled on the Macintosh without changing a single line of source text.
Registration
MacOberon is free. However, we would like to know who is using it. Please send a postcard with the words "I like MacOberon" (or the opposite, if you don't) and your name and address on it to:
Michael Franz
Computersysteme ETH
8092 Zurich, Switzerland
Picture postcards are preferred, because we can paste them to our wall... If you give us your E-mail address, we will also keep you informed of updates.
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