From: "wesley_ae" <awesley@acquerra.com.au>

Date: November 28, 2005 4:16:51 PM MST

To: Astro_IIDC@yahoogroups.com

Subject: Re: DMK camera fixes itself - is there some kind of timeout?

--- In Astro_IIDC@yahoogroups.com, Milton Aupperle <milton@o...> wrote:

Steve;

Okay - What you DIDN"T say was that Astro IIDC is still running after  

you unplug - replug, nor did you say any error messages show up. What  

your doing is just not a "smart thing" to do and if you try that with  

any device that is actively transmitting data, the results are  

unpredictable. That's the same thing as simply pulling the plug on  

your Mac while it's copying files, rather than shutting it down form  

the Apple menu. If you do that with a IDE, SATA, SCSI,  USB or   

FireWire hard drive while transferring files, you can lose entire  

volume as the disk map can become corrupted - let alone kernel panics  

and other fun things.

When the Camera control window is up, Astro IIDC has an open  

connection to the camera hardware and may still be reading /  writing  

IO control data. If you unplug it, it's left dangling and it is not  

going to refind the device. Under OS 9 it might have been able re- 

connect itself, but not under OSX - which is far sloppier and less  

robust as far as finding and connecting to devices goes. That's why  

so many people have had problems with FireWire hard drives and have  

lost complete volumes of information with each new X.x.x upgrade of  

OS X.

Milton, is that really the way that Astro_IIDC is written? I find that

a bit surprising. I use Linux for my firewire imaging and an

application called Coriander which lets me unplug and replug my

firewire camera as often as I like without crashing.

If I unplug the camera then it cleanly shuts down any capture stream

and puts up a dialog box saying something like "No firewire camera

present. Please connect a camera to continue". It sits there patiently

until I plug a camera back in (either the same camera or a different

one) and then the dialog closes and the application resumes with the

new camera.

I assumed that all firewire applications would behave like this, as

the firewire protocol has more than enough flexibility to allow it.

It's vey sad to hear that unplugging a firewire camera could cause any

sort of crash. That is reminiscent of a different operating system...

regards, Anthony