OSDev.org

Colonel Kernel wrote:I will only point out that it's much easier to change a multi-process single-tasking OS (like iPhone OS) to do multi-tasking than it is to change a single-process OS like DOS to do multi-tasking.

If the iPhone's resolution is 480x320, and the iPad's resolution is 1024x768, then you could remain compatible with iPhone apps by having them inside of windows which can be resized between 480x320 and 1024x768.

It seems to me that some OS Dev's are splitting hairs, on the multi- v single tasking debate, we all know multi-tasking is just time sharing ( forget multi cores for now), in which you switch between more than one app (as far as the use see).

Now on that point Dos was multi-tasking, with its TSR
http://www.smartcomputing.com/editorial ... .asp&guid=
http://en.wikipedia.org/wiki/Terminate_ ... y_Resident

The next thing that was pointed out is things like playing music in the background, its done in hardware , apple designs its own hardware its so simple to have a mp3 etc in avery small chip, my single-tasking OS can play CD in the background and open and run any DexOS app ( the cd drive is a self contained cdplayer), anyone with a old PC knows you could put a CD in the cd drive, press the button on the cd draw and it would play, without the OS help.

Then M$ stop Co from puting the wire from the drive to the sound card, now you need the OS to do the work.

earlz wrote: Why do you persist in annoying the OSDev community?

Only the members that are dumb, as being wrong all the time can be annoying .

Err, no. The iPod app is actually running in the background. The iPhone/iPod Touch's OS is fully pre-emptively multitasking; it has to be to run the cellular stack. It's just Apple block this, as anyone with a jailbroken iPhone will tell you

(/Happy non-crippled Symbian phone owner)

As for the ability for CD drives to play audio direct to the sound card? It was dropped for cost reasons, along with no longer being necessary (When your processor runs at 2GHz, doing DMA between the CD & sound card is no longer slow). Also, CD drive DACs are a pile of crap, the analog audio cables were unshielded and picked up a lot of digital hash (Particularly bad with modern CPU power supplies), and the signal routing on the sound card was also often low quality

Dex wrote:It seems to me that some OS Dev's are splitting hairs, on the multi- v single tasking debate, we all know multi-tasking is just time sharing ( forget multi cores for now), in which you switch between more than one app (as far as the use see).

Now on that point Dos was multi-tasking, with its TSR
http://www.smartcomputing.com/editorial ... .asp&guid=
http://en.wikipedia.org/wiki/Terminate_ ... y_Resident

The next thing that was pointed out is things like playing music in the background, its done in hardware , apple designs its own hardware its so simple to have a mp3 etc in avery small chip, my single-tasking OS can play CD in the background and open and run any DexOS app ( the cd drive is a self contained cdplayer), anyone with a old PC knows you could put a CD in the cd drive, press the button on the cd draw and it would play, without the OS help.

Then M$ stop Co from puting the wire from the drive to the sound card, now you need the OS to do the work.

earlz wrote: Why do you persist in annoying the OSDev community?

Only the members that are dumb, as being wrong all the time can be annoying .

Of course, and if people want to download a file in the background, you have to buy the DexSoft Back-Download chip for $49.95. And if you don't have room because of all the other expansion chips your using you have to also buy the DexSoft 1-4 Multiplexer Card which enables you to have enough room to have background music, downloads, instant messaging(the client always running in the background to notify you), and server programs that you wish to run on a non-dedicated/development server.

Thanks, but I'll stick to my perfectly fine PC hardware and OpenBSD OS that can do all that without extra equipment on the cheapest of hardware. Oh, and I also like being able to have more control over my CD player than "next" and "play" which is on most cd drives. Actually, new CD drives no longer have this built in audio crap.. and for good reason.

and anyone else agree that Dex bested us and that his OS is the future? A future where everything is just a $50 extension chip away? You remind me of those emo kids that think they are right because they are different from everyone else. Really, do you read what you type sometimes?


btw, I'm really seeing this thread getting locked or moved to auto delete very quickly...

You just do not learn do you: http://www.tuaw.com/2008/02/11/new-hybr ... ip-debuts/

Geez, you really know how to annoy people.

TROOOOOLL! TROLL IN THE DUNGEONS!

Dex wrote:You just do not learn do you: http://www.tuaw.com/2008/02/11/new-hybr ... ip-debuts/

There is a difference between offloading video processing and offloading all background tasks as you suggested.

iPhone SDK Programming: A Beginner’s Guide wrote:Short-Lived Applications
Another iPhone application limitation is that it cannot be memory-resident. A memory-resident
application can run in the background while a user runs other applications. Forget about
memory-resident applications when programming for the iPhone. You can’t do it.
An iPhone can only have one program running at once. This restriction puts your application
in constant danger of the OS terminating it. Think about it: Allegedly, an iPhone’s primary
purpose is still that of a cellular phone. A phone call might arrive while your application is
running. In this situation, the OS asks a user if he or she wishes answering the call. If the user
chooses to answer the call, the iPhone OS terminates your application.
Because of this constant probability of sudden termination, you should program defensively
and anticipate abrupt terminations. You will see that the UIKit makes this easy by providing
event handlers you can implement whenever your application is about to terminate.

Just thought it might be relevant.