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[Hal MacArgle <halinux AT kvinet.com>]

Greetings: Sindi asked that I forward this:


Floppymeter fun (another new posting).

We tested out about 20 floppy drives.  Two which don't format a known good 
disk without finding imaginary bad spots were spinning too slowly and had 
deviations of about +1500 ppm on capacity.  So did one which makes disks 
that other computers cannot read.   We recycled those and a couple with 
very high negative deviations on capacity (they spun too fast).  The very 
worst drive was about -4600 ppm deviation on rotation time (spun at 
199,100 instead of 200,000).  Unfortunately that is the one in our 486 
laptop which we don't have a replacement for.  It will read disks that it 
formatted but not disks formatted elsewhere so to test it first we had to 
format two disks, copy BL2 to them, then floppymeter (on disk 2).  Would 
not run off the original disks.    What makes drives run too fast?

If they spin too fast but transfer data too slowly the problems cancel 
out, as the capacity deviation ppm equals time per rotation added to data 
transfer rate.  Most drives spun too fast and transferred a bit slowly or 
a bit fast.  All bad drive were way off on spin speed.

One drive was very noisy and spun very slowly.  One did not work at all.
We now have 8 fewer floppy drives.  

The best drives had deviations under 1000 ppm.  TEAC (TUV, Mitsumi) was 
consistently excellent (under 500 ppm, in one case only 70) with one 
exception, and we have about 10 of them.  Toshiba was bad both times and 
the front covers were also loose or missing.  Packard Bell was sloppy, 
rotation speed kept changing.  IBM/ALPS - one good, one rotten.  Same for 
Panasonic.

We have about 10 360K drives which have never had any problems.  My first 
360K needed cleaning after about 5 years heavy use on a computer with no 
hard drive.  I hear that they could also be realigned.  

End of forward: