realtime embedded systems doubt

It most certainly does, and it runs great on robots - I have used it several times on robotics projects.

Have you ever surfed the web on your cellphone?

Sorry, it's not possible.

:-)

Hey! My web-enabled cellphone just disapeared in a puff of smoke!

Can I get you to say that lawyers are imossible? :)

Embedded System : a computer Embedded inside another machine or system. Real Time: the computer will respond to simulus within a guaranteed amount of time. Ever notice windows lagging while some program is busy? it would not be too good if your breaks where delayed because you changed the radio station.

Yes.

No. QNX is a modular system ... it can be configured as a tasking kernel only, as a complete Unix work-alike with file system and networking, or as almost anything in between. The operating system is adapted to new hardware by writing device drivers.

You don't surf or edit with the operating system, you do these things with application programs which run on top of the operating system.

You won't see it unless you get the development package and write yourself a timing critical program.

I wouldn't know.

Your computer is a device isn't it?

George

QNX is different than desktop operating systems in many ways. It is factored into pieces that let you use just the pieces that you need without using all the pieces. Remember when Microsoft claimed that they just couldn't remove their browser from the desktop without everything crashing down.

Partly because of the factoring of parts and partly because of the way the parts were designed it is designed to have much harder real-time responses than typical desktop environments. Real-time is not a hard definition but a sign that something isn't real-time is when a user stares at an hour-glass icon until they decide to take a coffe break and come back.

Software design! It depends on which device you choose to use. Some devices will let you surf the web others won't. Some will use a mouse, some will use an IR Remote, some will use a touch screen, some will use voice, etc. etc.

There was a recent thread about the difference between the terms real-time and embedded systems that you should find very educational. There were lots of good posts and a little quibling about whether a payroll system that produces output once a month, or sometimes prints out the checks a few years late, is really real-time or not. ;-)

Best Wishes

..which is something that you *really* don't want to happen to your anti-lock brakes, pacemaker, or nuclear power plant colling system... :)

I hate it when I have to delay my breaks. But it would be more serious if my brakes didn't work while driving.

Simple. Real time is an operating system that has been constructed correctly. Your desktop operating system cannot be used as real time operating system because it was designed by people who would not know a real time operating system if it fell on them.

Considering the fact that they thought that giving an incoming email the power to read your address book and send emails to people on it was a fine idea, it's a shock that they have figured out how to alternate inhaling and exhaling.

new

Both concepts "real time" and "embedded" are really understood in many ways. You can find numerous definitions for both, easily. All OS'es can be used in embedded systems of some kind. Some just perform better doing this than others....

???

Are you referring to QNX with that?

Pygmi

Sorry my context sensitive spell checker missed that one.

The Spellchecker Song:

I have a spelling checker. It came with my Pea Sea. It plane lee marks four my revue Miss steaks aye can knot see.

Eye ran this poem threw it. Your sure real glad two no. Its very polished in its weigh, My checker tolled me sew.

A checker is a blessing. It freeze yew lodes of thyme. It helps me right awl stiles two reed, And aides me when aye rime.

Each frays comes posed up on my screen Eye trussed too bee a joule. The checker pours o'er every word To cheque sum spelling rule.

Bee fore a veiling checkers Hour spelling mite decline, And if we're laks oar have a laps, We wood bee maid too wine.

Butt now bee cause my spelling Is checked with such grate flare, There are know faults with in my cite, Of nun eye am a wear.

Now spelling does not phase me, It does knot bring a tier. My pay purrs awl due glad den With wrapped words fare as hear.

To rite with care is quite a feet Of witch won should be proud, And wee mussed dew the best wee can, Sew flaws are knot aloud.

Sow ewe can sea why aye dew prays Such soft wear four pea seas, And why eye brake in two averse Buy righting want too please.

And the unteachable annoyance fails to snip 70 odd lines of irrelevant quotation, while irritating the world with YATP. PLONK

Soon he will be plonked by everyone here and we can go back to discussing embedded systems without a yapping (yatping?) little dog bothering us.

BTW, there is no need to call me "God." "Guy" will suffice. :)

Getting back to the subject of QNX, it has been a while since I used it on a project. I usually work on the low end (4-bit uP with

? That wasn't a quote.

Tell us - what is your expertise in embedded systems? You haven't seen fit to share any of it yet, which would be appropriate before maligning others.

But I forgot, you're handicapped. I just realized what it is - one stone. While I'm sympathetic for your loss, that really shouldn't affect your performance much.

I don't think you can say a non-real-time operating system is incorrectly designed. It just has different goals.

For example, A desktop operating system (especially multi-user systems) try to be "fair" when allocating system resources. An RTOS tries to be "correct." An RTOS has no qualms about starving a philosopher, if that's what's required.

Regards,

-=Dave

I haven't posted here for some time. I used to post quite regularly until the groups got swamped by flame wars and self appointed net cops. I used to come here for a little pleasure, and to see if I could perhaps be of help to someone, but the recent influx of narrow minded bigots has taken all pleasure away from the experience. I still try to help, of course, but you can't sway a religious fanatic into believing there's more than one way to do things..

There are many here who know me. I have nearly 35 years experience as an engineer and designer. I have managed the systems division of a US corporation, consulted to Stoke Mandeville spinal injury unit, the VA rehab centre in Palo Alto, and the USAF, among others, and employed many engineers over the years in my own companies.

Within the last 2 years I've developed systems for military use which are under trials in the US. A 14 frame per second 4 image per frame, image processing system, based on an MSP430 ($600k in systems sold since shipping #1 last July). A non-intrusive scanning device which can detect tumours within 1cm of the skin surface before they reach pin head size, about to start clinical trials. And an adaptive pain suppression system, currently being trialled. I did want to enter the DARPA autonomous UGV contest, but they only allowed US residents to play, and travel is a bitch these days. Not much I know, but I've had to fit spinal surgeries, and a pretty nasty bout of diverticulitis in between work. Hopefully I'll do better next year.

Call it what you will, at least I'm not hampered by a narrow mind.

I guess that has to be an American joke. It doesn't play in English.

Al