jordan@hpfcdj.HP.COM (Steve J. Jordan) (04/04/91)
Need advice: I have a non-apple brand 5.25 floppy connected to the Smartport on my GS (along with my Apple 3.5.) The 5.25 drive has worked fine for about 2 years, and usually it still does. The last month or two I've sporadically had various 5.25 floppy disks stop working for no apparent reason (won't boot, I/O errors, etc.) My guess is that the 5.25 drive is occasionally trashing my disks. I figured my CPU board must be ok since my 3.5 drive (daisy-chained to the 5.25) hasn't had any problems. There isn't anything nearby that could be giving off large magnetic fields to directly damage my disks, and I can't think of anything else that might be causing the problem. So, assuming the 5.25 drive is the problem, what should I do? Are there some tests I could run to check it? I ran a drive speed test available on my old Locksmith disk. It looked fine. Is it worth bringing to a dealer to check? Or will that cost as much as buying a new drive? (I saw one in A+ for $99.) I can't seem to get the drive to fail while I'm watching it, so (with my luck) a dealer couldn't either (& still charge me.) I'm starting to wonder if it's trashing disks when I power-up & power-down my system with a disk in the drive. Do all 5.25 drives properly handle powerup/down? (ie. the write-head should not be skipping around.) Steve Jordan jordan@hpfcdj.hp.com
toddpw@nntp-server.caltech.edu (Todd P. Whitesel) (04/06/91)
jordan@hpfcdj.HP.COM (Steve J. Jordan) writes: >wonder if it's trashing disks when I power-up & power-down my system with a >disk in the drive. Do all 5.25 drives properly handle powerup/down? (ie. the >write-head should not be skipping around.) This I can answer right away. If the drive motor isn't spinning, the disk can't be modified -- IF the drive electronics are working properly. The light should also only be on when the motor is actually running. It is possible for the drive electronics to experience an age problem in which they accidentally kick into write mode about 1/3 of the time they are stepped to a new track. One of my friends had this problem in a cheap mail-order drive he got five years ago; we had to replace the MC3470 to fix it. (We swapped chips between drives to figure that out.) Todd Whitesel toddpw @ tybalt.caltech.edu
schiffer@stsci.EDU (Skip Schiffer) (04/18/91)
toddpw@nntp-server.caltech.edu (Todd P. Whitesel) writes: > If the drive motor isn't spinning, the disk >can't be modified -- IF the drive electronics are working properly. Although this statement is correct (with the IF clause) it is true that in the Apple drives the write electronics and the motor electronics are independent. It is possible to activate the write without enabling the motor. (In fact it is possible to enable the write without addressing the drive if the electronics fails the "proper" manner.) I spent more than a week proving this problem with a defective Apple 5.25" drive approximately 6 years ago. Just to keep the record straight. Skip -- | F. H. Schiffer 3rd | | | schiffer@stsci.edu | I speak for myself alone. | | scivax::schiffer | |