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From: pnm@goanna.cs.rmit.oz.au (Paul Menon)
Newsgroups: comp.sys.mac.hardware
Subject: Re: Hi Density Disks -- high failure rate
Message-ID: <5097@goanna.cs.rmit.oz.au>
Date: 3 Apr 91 09:12:59 GMT
References: <1991Apr3.003702.14936@hawk.cs.ukans.edu> <1991Apr3.041443.12295@en.ecn.purdue.edu>
Organization: Comp Sci, RMIT, Melbourne, Australia
Lines: 69

In article <1991Apr3.041443.12295@en.ecn.purdue.edu>, tmattox@en.ecn.purdue.edu (Timothy I Mattox) writes:
> In article <1991Apr3.003702.14936@hawk.cs.ukans.edu> chai@hawk.cs.ukans.edu (Ian Chai) writes:
> >Has anyone else had problems with a high failure rate with the
> >1.44 meg disks?
> Yes.
> 
> DUST DUST DUST!!!!!!!
> Here at Purdue, we have several Mac labs, with 20-30 Macs each.
> They are left on most of the day for 5 to 7 days a week.
> For the Mac IIcx's they act like vacuum cleaners, with the floppy drive
> being the largest opening on the case directly in-line with the fan.
> I generally have to try two different machines to get one with a working drive.
> 
> It seems as if the 1.44 Meg disks are much more sensitive to dusty drives.


Err, I might have something to refute this.  We also had really bad 
experiences with the 1.44 MByte floppy disks and drives.  They appeared to
flake it when either ..
    *	files on the floppy had to be replaced (a common situation if
	they are used as 'shuttles' or 'archives')
		    or
    *	a large number of files exist on the floppy
		    or
    *	a large number of files are being copied to the floppy
		    or
    *	a combination of the three.

What really shook me was that IT WASN'T A TERMINAL HARDWARE (FLOPPY) PROBLEM!!

    *	The MultiFinder still cannot cope with copying large numbers
	of files at a time.  Yes, I know - increase the mem given to the
	finder, but still those (Sorry, read error, cancel/continue???) 
	rather silly messages crop up.  It's usually after this that the 
	problems start - the typical message being something like 'This is
	not a Mac Disk, initialize/eject??'.  No amount of coaxing the
	Mac (or should I say 'FInder') to accept this disk as is works.
    *	Take any reasonable Disk Copying program (try Apple's DiskCopy, it
	may also work) which overrides the default System 'eject/init'
	joke and format the disk.  It Works!!!
    
Conclusion - 	
		The moronic Finder/MultiFinder/System is the cause of these
		woes.  It cannot even reformat a zonked floppy after it's been
		through the mill (as described above), EVEN THOUGH MOST OTHER
		FORMATTING UTILITIES LET YOU!

		You do not have unusable, faulty disks: don't throw them away 
		like I did.  You can still re-format them.  You just can't
		use the dopey default mechanism.

		I cannot point to the original cause of this problem.  It may
		be marginal specs, but I suspect the 
		Finder/MutliFinder/System combo because of its inability to
		even copy large numbers of files twixt hard drives 
		successfully.  I suspect it leaves the floppy in an aborted
		mess after such a failure.  Maybe this is fixed in System 7 -
		if not there's always System 25 - some of us may still be 
		alive.

    Paul Menon,
    Dept of Computer Science,
    Royal Melbourne Institute of Technology, 
    124 Latrobe Street,
    Melbourne 3001, 
    Victoria, Australia.

pnm@goanna.cs.rmit.oz.au
PH:	+61 3 660 3209