regarding ISR

This is comp.arch.embedded - unless you know what you are doing (and you clearly don't), you shouldn't use dynamic memory at all. You certainly should not allocate any during an ISR.

Before posting again, please learn to type correctly.

May I suggest, that for a different view, you read: The Cell Phone: An Anthropology of Communication By Heather A. Horst, Daniel Miller

Available from Amazon et al.

Stephen

Could you summarise this "different view" for me? "An Anthropology of Communication" does sound somewhat interesting, but my things-to-read list is already long enough to last a lifetime...

mvh.,

David

Sure. Just don't forget to throw an exeption in the destructor.

VLV

In some areas of the world, a mobile phone is an important acquisition, and early internet access will be through it. With the cost of mobile phone access, people learn to compress their costs by compressing the text.

Hence, a side effect of SMS-speak appears on the internet. It's a bit like the days when we had 110 baud modems and minimal pocket money.

Be nice to your global neighbours!

Stephen

This depends very much on your hardware and software architecture. In general it is a bad idea to allocate memory in an ISR. Since you mentioned no specific platform, I would suggest you NOT do it. Ed

As long as they know that they're also "compressing" the liklihood that they'll get a useful response. I, for one, don't want to spend my time uncompressing SMS-speak, so I usually just ignore such posts.

Let me point out that Usenet is NOT - repeat NOT - a Cell Phone.

I *am* nice to my global neighbours (I even gave him as good an answer as possible, given the question) - as I am an ex-pat, I am well aware of the difficulty of writing accurately in a second language. However, I don't really buy your idea that SMS-speak is saving costs. You don't pay per letter for SMS messages (at least, I've never heard of such a scheme) - you pay per message. SMS abbreviations are nothing more than laziness. That's fine for teenagers chatting together - it's not appropriate in a newsgroup for professionals and serious amateurs.

I'm quite happy to talk with non-native (or native!) English speakers using "imaginative" grammar - but I expect people to use full words or standard newsgroup abbreviations, I expect them to get capitalisation and punctuation roughly correct, and I expect them to use a spell checker (from any half-decent newsreader, or browser for Google groups) to get most words correct.

Thus I fairly politely ask posters to communicate in the language of this newsgroup - it's in their interests to learn, since it will help them be more professional, and they'll get answers from Grant Edwards!

You are right they charge by the message not the letter. But alot of phones have a limit to the message size. On occasions you could compress the words to have a single message instead of two. Of coarse, I argue just to get the unlimited messaging plans. Or phones that don't have text buffer limits.

I think the root of the difference is that usenet is a "one to many" medium, whereas texting or chatrooms are one-one or one-few.

In texts and chatrooms, it is generally good to be able to express something as quickly as possible, to make it like a face to face "real-time" conversation. It takes more effort to write a message than to read it, so you can argue it is not worth putting much work into the writing side, that would just slow things down.

But with usenet, there are hundreds of readers reading the post. So it is worthwhile putting effort in to the writing side, since even a small increase in "readability" is multiplied by the number of readers. Also usenet is less of a "real-time" medium than texts and chatrooms are.

It's not the phone that limits the message size, it's the SMS messaging system itself that limits a message to 160 characters.

From what I can tell, the abbreviations are mostly just to save keystrokes, since I don't think I've ever gotten an SMS message anywhere near the limit. Of course, I'm the wrong generation to get a lot of text messages -- almost all of mine are reminder messages from Google Calendar. :)

Yes, it's your CPU so you can do anything you want with it. You can can even disable IRQs or dynamic memory altogether if you really want to.

There are many, and this is by no means an exhaustive list but the first percautions that come to mind are correct handling of the following scenarios:

- The allocation fails because there is no more dynamic memory available.

- The allocation takes too long and causes a subsequent IRQ to be missed.

- The IRQ occurs while the mainline is in the middle of allocating/freeing dynamic memory and your memory manager is non re-entrant.

- A higher priority IRQ occurs and causes another ISR to start while this one is in the middle of allocating memory.

Other percautions will depend on whether or not you are using a paged memory architecture, and whether pages are being swapped to secondary storage, etc. You also might want to search for "deferred procedure call"

--Tom.

If someone is really posting questions using SMS messages, how is that person going to receive messages posted by other users ?

If by SMS, that would imply that the sending a single message is very expensive but you can receive an unlimited amount SMS messages for free. Is there really such a service anywhere in the world ?

Paul

I don't think anyone is actually posting to Usenet via SMS (I'm sure it's possible - after all, someone actually implemented RFC1149, although they did not bother trying out Usenet). Stephen was suggesting that a reason for people posting in SMS-speak is that they are used to using SMS, and simply carry the same "language" over to Usenet.

I think there is a lot in what you say here. People often don't seem to understand Usenet - they think in terms of posting a question and getting an answer, rather than having a discussion for the benefit of many. They also often fail to realise that newsgroup archives are an important resource for the future - when you've solved a problem, and post the answer here, it's available for others searching the archives.

Good point about the archives - that's another factor I had intended to mention, too. The difference between writing a "txt" that will be deleted on reading, and a Usenet article that will likely remain archived and searchable until the end of time.

Possibly via an SMSemail gateway?

Not for free, but for a fixed price.

Let me point out I that I did not say that it was. I merely pointed out that the way one accesses Usenet may influence the content.

Stephen