Disk change and write cacheing (Was: Compaq Portable II -

[Jim Leonard]

Fred Cisin wrote:
> Since the OS had been told that the write had been completed, it declared
> the file closed.  "Go ahead and change disks now".
> If the file write was the last thing that the application program wanted
> to do (word processing often ends with file write, followed by human
> turning off the computer and dashing out the door), then the OS would
> return to the command prompt, before the sectors actually got written!
> "All done, you can turn it off now"

In defense of Microsoft, disk caches had been deferring writes for years 
before SMARTDRV.  It only became a problem for Microsoft because they 
deployed this as the default behavior without notifying the user.

I'd been using disk caches since the mid 1980s (anyone remember the 35K 
"Lightening"?) and willingly turned that behavior on since it made 
working with floppy-only systems tolerable.  But the difference with me 
is that I, an informed user, made that choice and was aware of the 
behavior.  I never lost data... but then again, I never suffered media 
failure.
-- 
Jim Leonard (trixter at oldskool.org)            http://www.oldskool.org/
Help our electronic games project:           http://www.mobygames.com/
Or check out some trippy MindCandy at     http://www.mindcandydvd.com/
A child borne of the home computer wars: http://trixter.wordpress.com/