Windows NT & Real-Time Extensions

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Martin Timmerman - chief-editor of Real-Time Magazine - introduces the subject like this: "The major reason is the invasion of Windows NT as a potential candidate for embedded (real-time) applications. The market considers Windows NT as a must in an open application, due to the availability of cheap hardware, including device drivers, protocol stacks and other software modules. Although I have no problems at all with this, for a lot of dedicated systems, predictable response is needed. The question then becomes: Can I make a predictable system using Windows NT?

A couple of years ago, Microsoft claimed real-time performance for Windows NT. We wondered how true this was and started an evaluation campaign. The resulting article, Windows NT and Real-Time, which you will find in issue 97Q2 of Real-Time Magazine, points out the problems with Windows NT in this context. It has been available on the WEB for a number of months now, and we received a lot of mixed reactions. Positive ones from the industries who appreciated the independent analysis and negative ones from some vendors being upset: the article was considered as a threat for the potential market that they have in mind. These vendors showed us how they would make Windows NT work in a system that needs predictable responses. The extensions they created are the simplest demonstration (if you don't accept the arguments in our article) that Windows NT in itself has severe problems in supporting deadlines. Studying these solutions, I found that the definition of a Real-Time System (RTS) is still not the same for everybody.

The solutions offered to produce a RTS with a predictable behaviour, seem also to differ a lot from one vendor to another. While some consider that having fast interrupt response is sufficient, others are more serious and rather prefer a multi-threading solution."

Real-Time Magazine did issue two major editions on the subject:

• 97Q2 issue - RTOS Update I
• 98Q3 issue - Windows & Real-Time

Our views about Windows NT
Windows NT as Real-Time OS ? By Dr. ir. Martin Timmerman, Managing Director, Jean-Christophe Monfret, Project Manager, Real-Time Consult. Paper published in Real-Time Magazine, 97Q2, page 6-13. More and more companies are trying to use Windows NT as a standard Operating System (OS) at all levels of the industrial hierarchy. The use as server and workstation is obvious, but some people want to use it also on the factory floor. These factory floor applications demand real-time system behaviour. Can Windows NT be a component to fulfil this need? First, we will define what a real-time system is and the OS characteristics we need to allow developers to build such a real-time system. The distinction will be made between hard and soft real-time systems. In the second part, we demonstrate how and why Windows NT cannot fulfil the requirements of a hard real-time system. We show, however, that for some simple soft real-time applications, Windows NT could be used under certain circumstances.
Could Windows NT 4.0 be used as a RTOS?
When Windows NT was originally designed it was not foreseen to be a real-time operating system. Yet many people are keen to use it as such and some already do so. Why would they want to do this and what are the advantages of Windows NT? This paper looks into those questions and explains the general architecture of the operating system. It also gives some results of performance tests that are useful for anyone who's interested in using Windows NT in real-time systems. The paper also gives some insights in the final RTOS evaluation report, released on Dec. 9, 1998.	This document is available for free download (Acrobat PDF, 238K - 15 pages) from our Visitor's Center.
Windows NT Workstation 4.0 - RTOS Evaluation Report
The Windows NT RTOS Evaluation Report serves as an example of the content and quality you may expect from any RTOS Evaluation Report drafted by Real-Time Consult.   An abstract from this document (including the Table of Contents & Table of Figures) may be viewed in our Visitor's Center.	To find out how to order or purchase the report online
Our views on Windows NT Real-Time Extensions
Windows NT Real-Time Extensions : an Overview By Dr. ir. Martin Timmerman, Managing Director, Jean-Christophe Monfret, Project Manager, Real-Time Consult. Paper published in Real-Time Magazine, 97Q2, page 14-24. In a previous article we discussed the impossibility of using NT as a Real-Time OS. (RTOS). In this article, we want to discuss and compare the solutions the industry is offering today to give NT a Real-Time flavour.  All solutions have potential advantages and drawbacks. This essentially means that each of them is probably useful in only a particular application type. The information in this paper should give the reader the capability of choosing the right solution for his kind of application. .
Evaluating Windows NT Real-Time Extensions By Dr. ir. Martin Timmerman, Managing Director, Jean-Christophe Monfret, Project Manager, Real-Time Consult. .	This document is available for free download (Acrobat PDF, 83K - 2 pages) from our Visitor's Center.
Windows NT Real-Time Extensions better or worse ?
By Martin Timmerman, Chief-Editor of Real-Time Magazine, Bart Van Beneden Project Manager, Laurent Uhres, Software Engineer, Real-Time Consult. Updated version from paper published in Real-Time Magazine, 98/3 - p. 11 This article presents an overview of the capabilities of the real-time extensions for Windows NT 4.0 as a real-time operating system (RTOS). The extensions that are covered are RTX 4.1 from VenturCom, INTime 1.20 from Radisys and Hyperkernel 4.3 from Imagination Systems. This paper is part of an evaluation project concerning real-time extensions for Windows NT 4.0. The final RTOS Evaluation reports of those products are available since Nov. 24, 1998.	This document is available for free download (Acrobat PDF, 1.07MB - 7 pages) from our Visitor's Center.
RTX 4.2 semaphore queue management enhanced!
VenturCom, Inc recently released RTX 4.2 real-time extensions for Windows NT. As part of a RTOS evaluation program, Real-Time Consult has been evaluating both RTX 4.2 and the previous release (RTX 4.1). This paper illustrates the improvement of the problematic semaphore queue management detected in release 4.1.	This document is available for free download (Acrobat PDF, 54K - 3 pages) from our Visitor's Center.
INTIME 1.20 - RTOS Evaluation Report Abstract & Content Table
The INtime 1.20 report evaluates INtime 1.20, the Windows NT Real-Time Extension from Radisys Corp. An abstract from this document (including the Table of Contents & Table of Figures) may be viewed in our Visitor's Center.	To find out how to order or purchase the report online
RTX 4.2 - RTOS Evaluation Report Abstract & Content Table
The RTX 4.2 report evaluates RTX 4.2, the Windows NT Real-Time Extension from VenturCom, Inc. An abstract from this document (including the Table of Contents & Table of Figures) may be viewed in our Visitor's Center.	To find out how to order or purchase the report online
HyperKernel 4.3 - RTOS Evaluation Report Abstract & Content Table
The Hyperkernel 4.3 report evaluates Hyperkernel 4.3, the Windows NT Real-Time Extension from Imagination Systems, Inc. An abstract from this document (including the Table of Contents & Table of Figures) may be viewed in our Visitor's Center.	To find out how to order or purchase the report online
Windows NT RT Extensions - Comparison Report Abstract & Content Table
This report compares the evaluation results for the following products: INtime 1.20 from Radisys Corp. RTX 4.2 from VenturCom Inc. Hyperkernel 4.3 from Imagination Systems Inc. An abstract from this document (including the Table of Contents & Table of Figures) may be viewed in our Visitor's Center.	To find out how to order or purchase the report online
Our reports compared to the OMAC Evaluation Report. OMAC has been publishing a hard real-time Extensions of Windows NT evaluation report. We position the Real-Time Consult RTOS evaluation reports against this report. Read our remarks here. .
Other relevant articles (from third parties)
Tackle real-time applications with Windows NT By Richard A Quinnell, Technical Editor, EDN Magazine .
Windows NT for real-time control: Which way to go? By Peter Cleaveland, Wayne Labs, Senior Technical Editors, I&CS Magazine