🚀 go-pugleaf

I'm trying to take advantage of the wondrous ability to perform i/o operations
asynchronously from program execution.  I've been able to write the file that
I want to write, but have been having trouble with the ioCompletion routine.
I haven't been able to find anything that would indicate how the operating
system calls the specified routine.  Does the toolbox pass any parameters to
the completion routine?  Does the toolbox make application globals available
to the routine?  If anyone could point me to a reference, either a pointer
into Inside Macintosh or some other source, I'd be very grateful.

Also, I've heard a nasty rumour to the effect that the floppy controller takes
so much of the cpu's attention that there is absolutely no benefit in doing
floppy i/o asynchronously. What little I've been able to get working tends
to support this.  Does anyone have any hard data on this?  Does the scsi
controller on Mac+'s suffer from the same problem?  (I would call it brain-
damage but I'm just getting over a bad sunburn and I don't need the heat)

Thanks in advance for any help.  
-- 
Breck Beatie
uunet!aimt!breck