lindsay@MATHOM.GANDALF.CS.CMU.EDU (Donald Lindsay) (07/31/90)
In article <V%6$_&|@rpi.edu> deweeset@turing.cs.rpi.edu (Thomas DeWeese) writes: >...the fact that they are not >evacuated is the major reason why the heads are able to fly so close to the >disk media. There's talk of head altitudes of 0.05 microns - that's 500 angstroms. Combined with two micron track pitches, the mechanical aspects are getting pretty tense. The problem with putting 10 GB on a 3.5" disk (a published research goal) is that the access structure has to be treated as non-rigid. Since it also has to be moved rapidly, the engineering is unobvious, to me at least. Hence, my rather naive wish that they'd find a way to use a simple head stick, with a piezo per head, or some such. The major trend in the _use_ of disk drives, is to carry them around in portables. Does anyone know how much of a compromise it is to get ruggedness? -- Don D.C.Lindsay
arun@tinton.ccur.com (Arun Kandappan) (08/01/90)
In <10058@pt.cs.cmu.edu> lindsay@MATHOM.GANDALF.CS.CMU.EDU (Donald Lindsay) writes: >In article <V%6$_&|@rpi.edu> deweeset@turing.cs.rpi.edu > (Thomas DeWeese) writes: >>...the fact that they are not >>evacuated is the major reason why the heads are able to fly so close to the >>disk media. If I remember right, the SMD disks of CDC had a head which would literally "take-off" and land. It was designed in such a way that any abrupt shutdown of the disk would not cause a crash because the head glides down. Arun
henry@zoo.toronto.edu (Henry Spencer) (08/02/90)
In article <36331@masscomp.ccur.com> arun@tinton.ccur.com (Arun Kandappan) writes: > If I remember right, the SMD disks of CDC had a head which would >literally "take-off" and land. It was designed in such a way that any abrupt >shutdown of the disk would not cause a crash because the head glides down. Essentially all modern disk drives do startup and shutdown that way. But the clearance has to be maintained during operation, which is why you need an air cushion under the head. -- The 486 is to a modern CPU as a Jules | Henry Spencer at U of Toronto Zoology Verne reprint is to a modern SF novel. | henry@zoo.toronto.edu utzoo!henry