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Newsgroups: comp.lang.oberon,comp.answers,news.answers
Path: bloom-beacon.mit.edu!hookup!news.moneng.mei.com!howland.reston.ans.net!agate!library.ucla.edu!psgrain!m2xenix!mikeg
From: mikeg@psg.com (Mike Gallo)
Subject: Comp.lang.oberon FAQ (monthly)
Expires: Sun, 1 May 1994 07:00:00 GMT
Reply-To: mikeg@psg.com
Organization: PSGnet, Portland Oregon US
Date: Fri, 8 Apr 1994 12:07:13 GMT
Approved: news-answers-request@MIT.Edu
Message-ID: <1994Apr8.120713.15265@psg.com>
Followup-To: comp.lang.oberon
Summary: This posting contains a list of Frequently Asked Questions
(and their answers) about Oberon. It should be read by anyone
who wishes to post to the Comp.lang.oberon newsgroup.
Lines: 176
Xref: bloom-beacon.mit.edu comp.lang.oberon:1741 comp.answers:4822 news.answers:17828
Archive-name: Oberon-FAQ/system
(* * * * * * * * * * * * * * * * * * * * * *)
Many FAQ lists, including this one, are available by anonymous
ftp from rtfm.mit.edu in the /pub/usenet/news-answers directory.
Thanks to all who have contributed! Further additions,
corrections, and suggestions are welcome.
mikeg@psg.com
(* * * * * * * * * * * * * * * * * * * * * *)
Comp.lang.oberon Frequently Asked Questions
The Operating System
Copyright 1994 Michael Gallo
(c) 1994 Michael Gallo
THE OBERON SYSTEM
From "The Oberon Guide"
For the present, we focus on the system Oberon, beginning
with a brief overview of its design principles. The underlying
dynamic model is extremely simple. There exists a single
process acting as a common carrier of multiple tasks. This
process repetitively interprets commands, which are the
official entities of execution in Oberon. Commands are atomic
actions operating on the global state of the system. Unlike
customary interactive programs, they rigorously avoid direct
dialogs with the system user.
Besides "single-process multitasking" and execution of
commands in lieu of programs, the Oberon System also features
automatic garbage collection, memory resident modules, text as a
built-in abstract data type, tools for editing text and graphics,
and program development tools.
From "Oberon: A Glimpse at the Future"
The result is a system that provides efficiency and
reliability rather than offering inflated size, which
dramatically increases the probability of bugs and flaws.
What is most astonishing about Oberon is its smallness.
The core operating system -- including the Oberon compiler --
occupies only 131 KB, which is smaller than most [Microsoft
(tm)] Windows utilities.
OBERON SYSTEM 3
From "Oberon System 3 -- A Realm of Persistent Objects"
We soon decided to realize our ideas by developing System
3, an evolutionary version of the original Oberon system. From
our vision and from examples like the one in Figure 1 it
followed immediately that System 3 needs to be settled one
important step beyond the ordinary state of object-oriented
programming because it needs to be able to manage hundreds or
even thousands of persistent objects and components that can
appear in extensive variety, including at least character
patterns, formulae, all kinds of figures, pictures, gadgets
and widgets. What was obviously needed is a central object
management and some concept like object library.
GADGETS
From The GADGETS User Interface Management System
The GADGETS user interface management system (UIMS)
is a graphical user interface to the Oberon system.
Although it is based on the representation model of
windowing user interfaces such as X Windows and
Presentation Manager, GADGETS is a conceptual departure
from the conventional graphical user interface (GUI).
Several features such as the separation of application
code and user interface, the interactive modification of
user interfaces while applications are executing, the
automatic generation of default user interfaces for
applications, and the simplification of user interface
programming have been incorporated into GADGETS. The
result is smaller, easier to build application programs
with a high level of integration between each other and
the Oberon system. The GADGETS UIMS is extensible and
provides a prototyping environment for alternative man-
machine interaction styles. The high level of
integration of GADGETS with the Oberon system makes the
addition of graphical user interfaces to existing Oberon
applications a relatively easy task.
VERSION COMPATIBILITY
"Is Oberon System version X compatible with version Y?"
According to templ@inf.ethz.ch (Josef Templ),
The Oberon ancestry is as follows
Oberon = V1 ( V2 V4 | System3 )
The main difference between V1 and V2 is the introduction
of an extensible text model and the text editor Write.
The main difference between V2 and V4 is the unification
of the two text editors Edit and Write. In order to avoid
confusion with System3, the direct successor of V2 is not
named V3 but V4.
The main difference between V2 and System3 is that
System3 introduced (a year later) a more general object model
(not restricted to text elements) and the notion of persistent
object libraries.
Many programs port between the different versions without
any changes. Some programs need simple textual substitutions,
and only very few need a considerable amount of reengineering
(e.g. Write, Script).
CONCURRENT OBERON
From "Adding Concurrency to the Oberon System"
Concurrency was not supported in the original Oberon
system. We have argued that, although the Oberon experience
has demonstrated that concurrency is not needed to support
interactive applications in a system with a multiple window
user interface, concurrency is nonetheless desirable in a
single user system. We have demonstrated that it can be
introduced without a significant increase in size or
complexity by developing the Concurrent Oberon system. Since
all interfaces remained the same or were extended, the
semantics of the Oberon loop were preserved. Concurrent Oberon
is completely compatible with the standard system [version 4]
and all applications run without change.
BIBLIOGRAPHY
Sources cited in the FAQ list that are not listed in the
bibliography are electronically available in PostScript and/or
Oberon text formats from ETH Zrich. They can be acquired by
anonymous ftp from:
ftp.inf.ethz.ch:/Oberon,
wuarchive.wustl.edu:/languages/Oberon, and
gatekeeper@dec.com:/pub/plan/Oberon
"Designing a System from Scratch" by N. Wirth; Structured
Programming; 10,1 (January 1989) 10-18.
"The Oberon System" by N. Wirth and J. Gutknecht; Software:
Practice and Experience; 19,9 (September 1989) 857-893.
The Oberon System: User Guide and Programmer's Manual by M. Reiser;
ACM Press; 1992. This was reviewed in Computing Reviews articles
9109-0679, 9209-0651, 9209-0652, and 9207-0443.
Project Oberon: The Design of an Operating System and Compiler by
N. Wirth and J. Gutknecht; ACM Press 1992.
"Implementing an Operating System on Top of Another" by M. Franz;
Software: Practice and Experience; 23,6 (June 1993) 677-692.
"OBERON for PC on an MS-DOS Base" by A. R. Disteli; Swiss Federal
Institute of Technology (ETH Zrich); Technical Report #203,
November 1993.
Distributed Object-Oriented Programming in a Network of Personal
Workstations by Spiros Lalis; Swiss Federal Institute of Technology
(ETH Zrich); 1994 (in preparation).
--
A designer knows he has arrived at perfection not when there
is no longer anything to add, but when there is no longer
anything to take away.
-- Antoine de Saint-Exupery