Talk:Real-time operating system
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[edit] Misc. Cleanup
[edit] Alt-Pcyberpunk
"...that has been developed for real-time applications." I'm not so sure about the "for".
As for the quotation at the end and its purported refutation - Forth solves the problem and provides a framework, without being an operating system unless you decide to define what Forth does as an "operating system". PML.
[edit] Remove non sequiter
- A new architecture is currently being developed.
Well, yes. New architectures are constantly being developed. Without any more detail, this doesn't tell me anything. MatthewWilcox 12:21, 15 Dec 2004 (UTC)
[edit] Incorrect or misleading content
I feel that some of the content in here is incorrect or misleading. I am going to make some changes. I hope not to offend anyone. Redslime 28 Sept. 2005 (UTC)
- So far, so good -- carry on!
- Atlant 12:25, 3 October 2005 (UTC)
Throughout the article, shouldn't it be 'an RTOS' instead of 'a RTOS'? (Assuming RTOS is pronounced 'are tee oh ess') --Anon
No, that is bad English.
"An RTOS" is right. —Preceding unsigned comment added by 24.30.138.61 (talk) 04:50, 9 April 2008 (UTC)
[edit] Has it occured to anyone...
that the article is full of self actualizing create talk that enerigzes the full potential of the collective bloggosphere synergy....
seriously can somone put this in terminology that doesnt link back to itself? (eg. "a real time operating system is a system that executes tasks in real time), such definitions really are not helpful.
EDIT, perhaps include content from this page http://64.233.187.104/search?q=cache:y9bdxyIM3LgJ:linuxdevices.com/articles/AT4627965573.html+%22real+time+operating+system%22&hl=en&client=opera i belive it provides and excellent defintions and explainations —Preceding unsigned comment added by 161.184.206.122 (talk • contribs)
- The referenced article contains at least one false assertion, that RTOSs provide an abstraction layer: this is not an essential feature of a realtime operating system. The article also gives the impression that an RTOS contains a number of features, such as i/o supervision, memory allocation, etc., none of which are necessary—but are convenient. —EncMstr 17:23, 8 August 2006 (UTC)
is the section about running the OS from ROM really necessary here? wouldn't it fit better in the article on embedded OSs? —Preceding unsigned comment added by Petrem (talk • contribs)
- Yes, I totally agree. —EncMstr 17:23, 8 August 2006 (UTC)
[edit] Totally bogus definition!!!
The qualifications of what constitutes a Real time Operating System makes no sense at all!!!
Comparing these examples:
- "Examples include embedded applications (programmable thermostats, household appliance controllers, mobile telephones), industrial robots, industrial control (see SCADA), and scientific research equipment."
To:
- "An early example of a large-scale real-time operating system was the so-called "control program" developed by American Airlines and IBM for the Sabre Airline Reservations System."
is like comparing a kite to the space shuttle.
Transaction oriented operating systems like TPF(the OS for the Sabre System) are considered real time to the user, but the actual response time can vary based on many factors including workload, network delays, etc. Industril-type applications that take input from analog devices can't guarantee a response time either because the analog input may differ.
The problem is the term 'Real time'. The perception of the term varies depending on the application and should never be used to categorize operating systems. —Preceding unsigned comment added by Klg53 (talk • contribs)
- A kite and the space shuttle are comparable when examining aircraft. The essential feature of an RTOS is latency determinism of an operation. Sabre is bound to respond to a transaction in a maximum time—which is determined by what is acceptable for reservation agents. Response times faster than the maximum are acceptable. A programmable thermostat has similar constraints: after a button is pushed, there is an expectation of the maximum length of time it may take to recognize the input and respond. That is the nature of real time. —EncMstr 17:23, 8 August 2006 (UTC)
That is a description of a very soft real time system. Compare that to a hard real time system such as a PC (or a CPU in an embedded system) monitoring a piece of lab equipment that is genrating a new data sample every 20ms, and which has to be polled for the data. If the PC lets more than 20ms lapse between polls an irreplacable data sample will be lost. That is a classic hard real time system and a good candidate for an RTOS. Rusty Cashman 09:14, 28 November 2006 (UTC)
[edit] Need more meat?
I was wondering if the following changes are reasonable..
- 1. First para -
What constitures real-time and what constitues a real-time OS has been discussed a zillion times before on the realtime newsgroup. Perhaps we should state the commonly accepted ideas and post a pointer to realtime faq here.
- 2. Third para - I find the refernce to Sabre resevation system as a real-time system to be controversial at best. All systems need to have some reasonable thruput and a lot of them have mechanism to ensure that they respond in good time .. but that doesnt make them real-time. If the sabre reservation system is late in responding what happens? Is the action result incorrect? Are there any references to the Sabre system being designed as a real-time system?
- 3. Design philosophies - If we agree on a definition for real-time OS, preferably as one defined in the comp.realtime faq.. it would probably be easier to discuss this. Assuming that all real-time os have to support a multitasking preemptive scheduler, the part about the time sharing thing falls as a sub-feature. (for all tasks with the same priority, you may have round robin scheduling based on time or some other event)
- 4. Intertask communication and resouce sharing - There is nothing inherently different about these tasks in a real-time system. I am not sure if its appropriate to talk about them here.
- 5. Interrupt handlers, scheduler, memory allocation - These (and I am sure there are more) are issues that have to be dealt with in designing a real-time system. perhaps having a section that talks about designing with RTOS and then listing these issues might be beneficial?
--Nitin Karkhanis 05:23, 9 November 2006 (UTC)
The FAQ is not apropriate. It is about real-time, not about a real-time OS. And say "tolerate hundreds of milliseconds of delays without a problem" to a video game player, or someone viewing a video with a new frame every 50 ms. Arnero 15:24, 1 March 2007 (UTC)
[edit] Separating Soft And Hard RTOS's?
I think it would be helpful to mention in the list of RTOS's which ones are capable of meeting hard real-time deadlines. Can someone who is familiar with these OS's do this? Also, perhaps mention some notable applications using each OS? —The preceding unsigned comment was added by 74.136.149.49 (talk • contribs).
- I haven't taken a close look at the list lately, but my my casual, unstudied opinion is that at least 75% of the links on the list ought to be thrown out entirely as non-notable linkspam; I've watched this list grow seemingly without bounds over the last several years. One rule of thumb I might apply is if the vendor doesn't show up at the Embedded Systems Conference, advertise in embedded-and-realtime magazines, etc., we toss them.
RTOS companies come and go. Requiring people to attend a conference or be a vendor? It reads to me like you have vested interest in the conference. If the link is bad then asked for it to be removed only after you have tried to make a phone call with the company. If there phone is no listed on the website then that may be a sign that is not legitimate. —The preceding unsigned comment was added by 71.255.37.169 (talk • contribs).
- Vested interest in the conference? Not at all. What I do have an interest in is enforcing the rules of Wikipedia and one of the rules is that you don't get to use us to advertise for you. Most of the RTOS's listed here are not in the least bit notable and should, therefore, be removed from this article. And the onus of establishing notability is on the person adding the information to the article and not on the rest of us.
- Atlant 23:46, 5 May 2007 (UTC)
[edit] Atropos?
Removed a link to the seemingly irrelevant article for Atropos. I'll admit that I didn't read the entire article through, but my cursory scan didn't reveal any correlation, and the article for Atropos mentions nothing of real-time operating systems (which, I'm led to believe, didn't exist during the time of the Greek deities). If I've missed something and actually removed a relevant link, please let me know on my Talk page and apologies all around. -Shane Lawrence 22:17, 6 September 2007 (UTC)
more over the response time of rtos is close to 0 as compared to non real time os and less memory is occupied by rtos as compared to normal os.
varun jha, kpit cummins 12:39,14 december 20007.
[edit] Why is Windows CE not mentioned?
As far as I know, Windows CE is also a real time OS? Why is it not mentioned? —Preceding unsigned comment added by 213.160.55.239 (talk) 12:23, 9 April 2008 (UTC)
