wheatley@inuxc.UUCP (Steven Wheatley) (01/05/84)
I recently tried to format a box of 3M DSDD reinforced hub diskettes. My tandon disk drive formatted them, with about 15-25K bytes unusable, and once or twice sounded as if it was going to die or fly apart while formatting. I called the 3M Diskette Hotline (1-800-328-9438) and they claim that the reinforced hub causes the tandon disk drive to press down on the hub too firm, as the hub is slightly thicker than other disks. They suggest that the disk be checked for the amount of pressure placed on the hub. My question: Has anyone else experienced this problem. Is it possible to check, or adjust the tension placed on the hub by the drive, without pulling it out, or taking the unit into a repair center. I can format dysan, and verbatim disks without any problems. Any insight (other than throwing the 3M disks away and sticking with dysan and verbatim....i am contemplating this option!) will be appreciated! Steve Wheatley inuxc!wheatley
burton@fortune.UUCP (Philip Burton) (01/06/84)
Your message raised several issues, some specific to Tandon or 3M, and some
general to floppy disk drives and media.
First, some of the hub ring reinforcements are too thick ( > 10 mils, I think),
so that the drive's clamp cannot seat properly. On the other hand, without
the reinforced ring, you may get centering problems if the clamp is a bit loose,
particularly with 80 track drives.
Second, Tandon drives are, in general, not always the best. Ask industry people,
even Tandon employees, and they will say that Tandon's busines reputation
doesn't include superb quality. So, you may have a drive problem. this seems
to be a problem more with Tandon drives from the aftermarket than those supplied
directly by IBM with the PC.
Third, 3M media is good, when it's good. Unfortnately, that too, isn't always.
For media, stick with Dysan, Verbatim, or Maxell, and you won't go wrong.
In short, to isolate your specific problem, try to reformat some Dysan or Ver-
batim reinforced ring diskettes on your drive, and then try to format your
3M diskettes on other Tandon or non-Tandon drives.
If this doesn't sound reassuring, then you're right. A real opportunity for
someone with a good reputation to put his label on everything to reassure
the public of good quality. (Hmnm, with a blue color ???)
Good luck,
--
--
Philip Burton, Fortune Systems, 101 Twin Dolphin Drive,
Redwood City, CA 94065 (415) 595-8444 x 526
{allegra,ucbvax!amd70,cbosgd,harpo,hpda,ihnp4,sri-unix}!fortune!burtonjones@fortune.UUCP (01/10/84)
#R:inuxc:-88900:fortune:14700002:000:1952 fortune!jones Jan 9 19:22:00 1984 I agree with Phil, but there is no particular reason why a diskette with extra clamping pressure would make unusual noises. The important thing to remember in the floppy world is that *nobody* is perfect. The best you can do is go with the vendors which have the highest average quality or take it upon yourself to check to actual performance. Bye the way, the diskette clamping pressure is set by the door adjustment. The door hinge is attached to the spindle lever arm through two screw slots. When the door is closed, the position of the lever arm with respect to the door guides is set by those screws. You could probably get it right if you are careful and willing to do over and over. I wouldn't recommend it to most people. When correctly adjusted, and I quote, you must "ensure there is a 0.010" +/- 0.001" clearance between the E-ring (aside - E-ring is what holds the cone/spindle) and the washer when the cone is clamped - the result of the front door being closed". Diskette envelopes not seating correctly are a possible noise generator. Out of tolerance envelopes can also cause data errors since they affect the head to media interface. On second thought, I guess you could generate noise with improper clamping, but that would take some heavy duty clamping. Are the hub re-enforcing rings on both sides of the diskette? Just to muddy the water a little more, some vendors (like Shugart) are real particular about which side of the diskette the hub ring is placed since they believe it affects the critical head penetration of head 1. A while back Verbatim was evaluating a thin built up polymer hub ring....that looked good. Gosh, how it all comes back as I think about it, another consideration is that the hub ring can act as an insulator which may allow static charge to build up on the diskette as it brushes by the liner, to be discharged by the head. I hate floppies, I really do. Dan Jones Fortune Systems Corp