hounsell@nmerh4.BNR.CA (Rob Hounsell) (01/09/91)
Folks, Thanks to those who provided answers to my query about "key 880" on disk validations. Now, on a similar topic: I've backed out my LUCAS/FRANCES boards, and am once again running a stock A1000. I am having problems with the internal drive, which can no longer seem to read or write the inner tracks on the floppy (i.e. tracks 77-79). I don't have a sector editor: I discovered which tracks it was choking on by trying to format several disks. I took both my internal and external drives apart (down to the drive assembly) and hooked the external drive up to the internal drive cabling: everything worked fine, including the formatting, so I'm convinced it's the drive itself. Unfortunately, the two drives have a slightly different physical layout, so I can't just swap them and bolt everything together again. Now, I've called two places around here to determine if the drive could be realigned, and was told that it was too difficult to do, and that they always replaced the units. One store quoted me $150 for the internal drive unit, and another $300! So, is there any PD software for drive alignment? Can it even be done? How would I do it (assuming access to an oscilloscope, if required)? Thanks again! Rob +-----------------------------------------------------------------------------+ | Rob Hounsell UUNET: ...!chekov!hounsell | | NT Product Support Technology BNR WAN: hounsell@nmerh4 | | PHONE: (613) 765-2904 | | ESN: 395-2904 | +-----------------------------------------------------------------------------+
monty@sagpd1.UUCP (Monty Saine) (01/12/91)
In article <3876@bnr-rsc.UUCP> uunet!chekov!hounsell writes: > Now, I've called two places around here to determine if the drive could be >realigned, and was told that it was too difficult to do, and that they always >replaced the units. One store quoted me $150 for the internal drive unit, and >another $300! So, is there any PD software for drive alignment? Can it even be >done? How would I do it (assuming access to an oscilloscope, if required)? To realign a drive requires an alignment disk and an o'scope. The hard part is finding the alignment disk. They usually run about $100 and do to there nature you can't 'pirate' one. Some of the tracks are physically skewed on the disk in the form of a sine wave so that when the heads read them they form a lissajous pattern. When you look at the two side of the differential output from the heads you get equal but 180 degree out of phase sine wave when the head is centered over the track. It is also necessary to have a test fixture or software that allows you to step to a certain track and stay there. It also is necessary to know where on the drive to pick up the amplified head signals so that you don't load them down and affect the readings. This is all assuming that the drive manufacturer has left some means of changing the alignment without special tools.o If you are going to do a lot of these, the disk is the way to go, but most of us have found that it is cheaper to purchase a new drive. Most IBM type 720k drives function eletrically in a A1000, it just becomes a case of creative physical mounting and asthetics. Good Luck Monty Saine
fmcphers@VTTCF.CC.VT.EDU (Frank McPherson) (01/22/91)
| In general, the makers of 3.5" floppy drives do not provide a mechanism for | aligning the drives. They are manufactured to tight tolerances at the | factory and are tested for alignment, but there isn't an adjustment for | aligning or realigning them per se. Although enterprising repairfolks may | find ways to change the alignment of individual units, people with drive | problems should probably write off the drive and just get another. This, to the best of my knowledge, is not completely true. A friend of mine is borrowing my Amiga 1000 right now. I stopped using it when I got my A3000UX. At the time I gave it to him, the internal drive was out of alignment. He's fixed it since then, and I do stress the FIXED part of that, so I have to assume that it is possible to re-allign at least SOME 3.5" drives. -- Frank McPherson INTERNET: fmcphers@vttcf.cc.vt.edu --
dueker@xenon.arc.nasa.gov (Chris Dueker) (01/22/91)
In article <1991Jan21.165909.6648@tc.fluke.COM>, kurt@tc.fluke.COM (Kurt Guntheroth) writes... >In general, the makers of 3.5" floppy drives do not provide a mechanism for >aligning the drives. They are manufactured to tight tolerances at the >factory and are tested for alignment, but there isn't an adjustment for >aligning or realigning them per se. Okay then, how about some means of determining if a drive is out of alignment? Forget the problem of trying to realign it, can I find out if it is out of alignment? I've got two drives (one internal, one external on my A1000) and sometimes some disks will work on one and not the other. I'd like to know which one is bad, so I know which needs replacing. Thanks in advance for help! ------------------------------------------------------------------------ "Ah, Benson, you are so mercifully free of the ravages of intellegence!" "Oh, thank you, Master!" - from the movie, TIME BANDITS ------------------------------------------------------------------------ dueker@xenon.arc.nasa.gov | Chris Dueker (The Code Slinger) duke@well.sf.ca.us | Mtn. View, CA (Sillycon Valley!)
johnhlee@hermod.cs.cornell.edu (John H. Lee) (01/23/91)
In article <1991Jan21.165909.6648@tc.fluke.COM> kurt@tc.fluke.COM (Kurt Guntheroth) writes: [...] >Those of you who are old hands will say "Nonsense, I remember realigning the >8" (or 5 1/4") drives on my old banana pc jr." Well, these older drives had >an alignment screw or adjuster or whatever, and the 3.5" drives don't. [...] This may be true for some drives (perhaps more likely for higher density drives), but all three 720K 3.5" drives I have on my A2000 (one each from Matsushita, Chinon, and Toshiba) can be aligned by loosening mounting screws and rotating the stepper motor, just like the 5.25" drives. ------------------------------------------------------------------------------- The DiskDoctor threatens the crew! Next time on AmigaDos: The Next Generation. John Lee Internet: johnhlee@cs.cornell.edu The above opinions of those of the user, and not of this machine.
esgbs@lims02.lerc.nasa.gov (GARY STANDEN) (01/30/91)
In article <51034@cornell.UUCP>, johnhlee@hermod.cs.cornell.edu (John H. Lee) writes... >In article <1991Jan21.165909.6648@tc.fluke.COM> kurt@tc.fluke.COM (Kurt Guntheroth) writes: >[...] >>Those of you who are old hands will say "Nonsense, I remember realigning the >>8" (or 5 1/4") drives on my old banana pc jr." Well, these older drives had >>an alignment screw or adjuster or whatever, and the 3.5" drives don't. >[...] > >This may be true for some drives (perhaps more likely for higher density >drives), but all three 720K 3.5" drives I have on my A2000 (one each from >Matsushita, Chinon, and Toshiba) can be aligned by loosening mounting screws >and rotating the stepper motor, just like the 5.25" drives. What about adjusting the speed on the Chinon drives? Dose anyone know if it can be done? If so how? Gary Standen > >------------------------------------------------------------------------------- >The DiskDoctor threatens the crew! Next time on AmigaDos: The Next Generation. > John Lee Internet: johnhlee@cs.cornell.edu >The above opinions of those of the user, and not of this machine.