ls1i+@andrew.cmu.edu (Leonard John Schultz) (12/15/90)
Does anyone know where I can get the ED floppy disks nesessary to format to 2.88 Megs on the NeXT? How about the price of the floppies, especially bulk rate. Len Schultz
jsd@arcadien.rice.edu (Shawn Joel Dube) (12/16/90)
In article <EbOPLTa00Uh784Okl=@andrew.cmu.edu>, ls1i+@andrew.cmu.edu (Leonard John Schultz) writes: |> Does anyone know where I can get the ED floppy disks nesessary to format |> to 2.88 Megs on the NeXT? How about the price of the floppies, |> especially bulk rate. |> I've seen a NeXT price sheet saying 5 for $99. I would guess that you could use 720k and HD (1.44m) disk if make a proper change on the disk. What I mean is that with a low-density 720k disk, drilling a hole in a corner will make the disk an HD one (or at least that's what the drive thinks it is). -- rrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr r ___ _ "...but then there was the r r /__ | \ possibility that they were r r ___/hawn |__\ube LaRouche democrats which, of r r jsd@owlnet.rice.edu course, were better off dead." r rrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr
tempest@walleye.uucp (Kenneth K.F. Lui) (12/16/90)
In article <1990Dec16.072544.233@rice.edu> jsd@arcadien.rice.edu (Shawn Joel Dube) writes: >proper change on the disk. What I mean is that with a low-density >720k disk, drilling a hole in a corner will make the disk an HD one >(or at least that's what the drive thinks it is). If you think you can get away with drilling a hole on a DSDD floppy hoping it will work with the same reliability as a DSHD disk, you are terribly mistaken. The converted disk will work initially, but the chances of data staying on the disk reliably is unknown because of the different magnetic formulation used on HD disks. This difference in materials is even more dramatic between HD and ED diskettes. Ken ______________________________________________________________________________ tempest@ecst.csuchico.edu, tempest@walleye.ecst.csuchico.edu,|Kenneth K.F. Lui| tempest@sutro.sfsu.edu, tempest@wet.UUCP |________________|
matthews@lewhoosh.umd.edu (Mike Matthews) (12/16/90)
In article <1990Dec16.072544.233@rice.edu> jsd@arcadien.rice.edu (Shawn Joel Dube) writes: >I've seen a NeXT price sheet saying 5 for $99. Hmm, I've seen 'em for 5 for $30. Can't verify that, though. >I would guess that you could use 720k and HD (1.44m) disk if make a >proper change on the disk. What I mean is that with a low-density >720k disk, drilling a hole in a corner will make the disk an HD one >(or at least that's what the drive thinks it is). Nope. The media is totally different, from what I hear. That's just ASKING for trouble anyway. Use the disk the way it's rated for, save yourself and anybody else who depends on that data some grief. >r jsd@owlnet.rice.edu course, were better off dead." r ------ Mike Matthews, matthews@lewhoosh.umd.edu/matthews@umdd (bitnet). ------ sig under construction, replies may have NeXT attachments
philip@pescadero.Stanford.EDU (Philip Machanick) (12/17/90)
In article <7724@umd5.umd.edu>, matthews@lewhoosh.umd.edu (Mike Matthews) writes: > In article <1990Dec16.072544.233@rice.edu> jsd@arcadien.rice.edu (Shawn Joel Dube) writes: > > >I've seen a NeXT price sheet saying 5 for $99. > > Hmm, I've seen 'em for 5 for $30. Can't verify that, though. Stanford price 5 for $27. -- Philip Machanick philip@pescadero.stanford.edu
tempest@walleye.uucp (Kenneth K.F. Lui) (12/17/90)
In article <1990Dec17.065959.19798@cunixf.cc.columbia.edu> ta-aca@cunixd.cc.columbia.edu (Andrew C. Athan) writes: >formatted ... but if it works the first time, its likely to retain data for a >LONG LONG time. If it works in practice --- it works period. > If it works for you, that's great; however, I wouldn't do it myself and wouldn't recommend it to anyone else. What are the prices for HD disks these days anyway? Aren't they inexpensive enough to not bother with drilling holes? >acheive much higher densities. I have yet to try formatting a 720 for ED >usage, but I would suspect the real-world failure rate to be very high. > Instead of using magnetic particles that's pin-like (for conven- tional longitudinal recording) ED diskettes use particles that are hexagonal in shape (for perpendicular recording). I read an article in Scientific American several years ago about this and I'm fairly sure that the NeXT floppy disk subsystem works in a similar fashion. Ken ______________________________________________________________________________ tempest@ecst.csuchico.edu, tempest@walleye.ecst.csuchico.edu,|Kenneth K.F. Lui| tempest@sutro.sfsu.edu, tempest@wet.UUCP |________________|
sef@kithrup.COM (Sean Eric Fagan) (12/17/90)
In article <1990Dec17.065959.19798@cunixf.cc.columbia.edu> ta-aca@cunixd.cc.columbia.edu (Andrew C. Athan) writes: >This is just EXACTLY what the disk manufacturers want you to believe. *Bzzt* Wrong answer, but thanks for playing anyway. >As far >as *I* know (and this has been confirmed to me over and over by people who'se >knowledge on the subject I trust...) the ONLY difference between HD and 720k >disks is the CERTIFICATION: i.e., the disk manufacturer wrote to the disk a >few times and verified that "yes indeedy this thing retains data." That is true, as far as it goes. But you forgot a step: they throw out any ones which don't pass teh certfication. And, yep, a few don't (how much depends on the manufacturer). If the manufacturing process is sufficiently high-yield, there is a much better chance that your 720k floppy will work in a HD drive. If, however, it isn't (say they use an older, less reliable plant for the 720k floppies), then you stand a much better chance of getting a bum floppy. Knowing all that, you takes your chances. I rarely use floppies, but I have run into ones that would not format at high density; these were returned to the manufacturer (since we bought them as high density). I should ammend that: they would format, but the verification would fail. -- Sean Eric Fagan | "I made the universe, but please don't blame me for it; sef@kithrup.COM | I had a bellyache at the time." -----------------+ -- The Turtle (Stephen King, _It_) Any opinions expressed are my own, and generally unpopular with others.