From: mccall@mksol.dseg.ti.com (fred j mccall 575-3539)
Newsgroups: comp.os.msdos.misc,comp.os.msdos.apps
Subject: Re: WARNING !!!!! MS WINDOWS 3.1 SmartDrive Problem
Date: 17 Aug 92 19:14:43 GMT
Organization: Texas Instruments Inc

In <1992Aug14.141659.328@csc.canterbury.ac.nz> cctr132@csc.canterbury.ac.nz (Nick FitzGerald, CSC, Uni. of Canterbury, NZ) writes:

>In article <1992Aug13.202720.22761@serval.net.wsu.edu>,
>mwoodwar@yoda.eecs.wsu.edu (woodward matthew d - CS350) writes:
>> In article <1992Aug13.040731.2286@cs.mcgill.ca> George Mitchell (passed on)
>> writes...
>[George Mitchell's warning about smartdrive deleted]
>> 
>> George is correct that this is dangerous.  This, however, is neither a bug
>> nor a problem with the Win 3.1 smartdrive program.  

>I agree it's not a bug - some may disagree that it's not a problem.  To
>make write-behind caching the -default- and --NOT-- clearly explain this
>to users - many of whom will have no concept of what disk caching is,
>let alone the potential problems of write-behind caching - is bordering
>on negligent, IMHO.

Last time I checked the docs, it WAS clearly explained.  Hey, nobody
ever explained it to me on any of the REAL computer systems I've used,
and it's not like SMARTDRV is the first write-behind cache program for
DOS. 

> 
>> The problem is PC users who don't think before they flip the switch, and 

>I thought you said there was no problem?

This isn't a problem if you read the documentation.  If you don't,
there's no way to change the behaviour of the power switch so it will
ask "Are you sure?" before it powers down.  Are there still people who
flip the switch within five seconds of writing to disk?

[Are there still people who flip the switch at all?]

>> Microsoft not trapping the warmboot vector to flush the cache before a 
>> warmboot.

>This is incorrect to the best of my knowledge.  

Indeed it is.  The cache flushes on a soft boot.

>With smartdrive loaded,
>at DOS proper - not a DOS prompt run from inside Win31 - the keyboard to
>screen response is slower on my 386/20-8MB than on an XT/4.77, much
>slower.  I take this as evidence that smartdrive totally usurps the
>keyboard for its own purposes - presumably to catch Ctrl/Alt/Del.  Once
>Win31 is running it can drop this practice, as Windows does the reboot
>checking for it and presumably signals smartdrive to flush its unwritten
>buffers should the user actually insist on rebooting.

Well, I don't think your 'evidence' is correct, though.  While
SMARTDRV.EXE does check for reboot and flush the caches on it, I've
certainly never noticed any such effect as you describe and can't
imagine why you would see it from SMARTDRV.EXE.  What happens if you
take SmartDrive off the machine with the 'slow' keyboard?

[I suspect a keyboard accelerator on the 'slow' machine to make its
keyboard faster, so the keyboard on the 'fast' machine seems slower.]


-- 
"Insisting on perfect safety is for people who don't have the balls to live
 in the real world."   -- Mary Shafer, NASA Ames Dryden
------------------------------------------------------------------------------
Fred.McCall@dseg.ti.com - I don't speak for others and they don't speak for me.
Newsgroups: comp.os.msdos.misc,comp.os.msdos.apps