s64421@zeus.usq.EDU.AU (house ron) (06/24/91)
I have a Connor 80Mb drive in my 386, which came with a big sign saying not to ever run any parking software, as the drive parked automatically and would be damaged by the software. Can anyone confirm the accuracy of this? What exactly would go wrong, and why? Just puzzled. -- Regards, Ron House. (s64421@zeus.usq.edu.au) (By post: Info Tech, U.C.S.Q. Toowoomba. Australia. 4350)
burton@asdsun.larc.nasa.gov (John Burton) (06/25/91)
In article <s64421.677770114@zeus>, s64421@zeus.usq.EDU.AU (house ron) writes: |> I have a Connor 80Mb drive in my 386, which came with a big sign saying |> not to ever run any parking software, as the drive parked automatically |> and would be damaged by the software. Can anyone confirm the accuracy |> of this? What exactly would go wrong, and why? Just puzzled. |> |> -- |> Regards, |> |> Ron House. (s64421@zeus.usq.edu.au) |> (By post: Info Tech, U.C.S.Q. Toowoomba. Australia. 4350) I'm not sure of the technical reason *why* head parking software would damage an autopark drive, but I've *seen* it happen (not a pretty sight :-) Most (not just conner) autopark drives (primarily voice coil) come with this warning...so there must be some reason for it... John
skipm@dorsai.com (Dorsai SysOp) (06/25/91)
s64421@zeus.usq.EDU.AU (house ron) writes: > I have a Connor 80Mb drive in my 386, which came with a big sign saying > not to ever run any parking software, as the drive parked automatically > and would be damaged by the software. Can anyone confirm the accuracy > of this? What exactly would go wrong, and why? Just puzzled. > I doubt this holds any validity. I will say that some parking software that is aged could conceivable screw up the drive by issuing it a command to park on a track/sector that is not the established landing zone. That Connor - I would guess it's an IDE? Or is it SCSI? Connor's, as far as I know, do auto-park on power failure. Western Digital IDE's however, do not. Skip ************************************************************************** ** SkipM@DORSAI.com - The Dorsai Embassy / Dorsai Diplomatic Mission ** ** (Systems Manager) - Consulate : (212) 431-1944 ** ************************************************************************** ** "The difference between a good man, and a bad man, is the choice of ** ** cause." - Unknown ** **************************************************************************
maurice@sol6.cs.monash.edu.au (Maurice David Castro) (06/26/91)
From article <1991Jun25.122949.13109@news.larc.nasa.gov>, by burton@asdsun.larc.nasa.gov (John Burton): > I'm not sure of the technical reason *why* head parking software would > damage an autopark drive, but I've *seen* it happen (not a pretty sight :-) > Most (not just conner) autopark drives (primarily voice coil) come with this > warning...so there must be some reason for it... I can not comment on the modern autopark drives, but a few years back, when 286s were young, there was a warning not to use XT harddisk parking programs with certain AT harddisk units. No explanation was offered at the time for the behaviour, however, the following is a suggestion: * IBM harddisks are a mess when it comes to parking zones, an AT bios lists many different tracks for parking or shipping the disk. XT programs do not access the bios list and hence do not know where to park the drive. As to the current problem the following is a possibility: * One parking program basically seeks the last track on the disk and parks over that. This works on some drives, however, this method would not actually place the heads in the right place for a voice coil self parking drive. If anyone knows the real story ... -------------------------------------------------------------------- Maurice Castro | "In hardware engineering, Ohm's maurice@bruce.cs.monash.edu.au | law and Maxwell's equations pale | in importance and influence next | to Murphy's Law" Gordon Bell -------------------------------------------------------------------- -- -------------------------------------------------------------------- Maurice Castro | "In hardware engineering, Ohm's maurice@bruce.cs.monash.edu.au | law and Maxwell's equations pale | in importance and influence next
amichiel@rodan.acs.syr.edu (Allen J Michielsen) (06/27/91)
In article skipm@dorsai.com (Dorsai SysOp) writes: >s64421@zeus.usq.EDU.AU (house ron) writes: >> I have a Connor 80Mb drive...which came with a big sign saying >> not to ever run any parking software, as the drive parked automatically >> and would be damaged by the software. >I doubt this holds any validity. I will say that some parking software... >I know, do auto-park on power failure. Western Digital IDE's however, >do not. I don't know connor's problem, but I have fixed drives where this was done. BACKGROUND: Drive parking can be done at several points in several manners. The controller can (be mfg'ed) sense power failure and issue a park command, or the drive interface can do the same thing. A park command can be done several ways,last cyl figured and seek commmand issued, first cyl seek command issued, or most commonly a seek_HI_# command issued. In this case, knowing that the drive is dowing down, and time is a issue, a out_of_range seek is issued to get the drive done ASAP. When this is done twice, the heads can be jammed against the inside hub rail, killing the drive. Using the original IBM AT 20 MB CDC disk with a Western Digital controller caused this problem all the time, as the western digital was designed with a park address high, and the drive with park at 0. Further the drive had like zero overrun at the high end, and they jammed up. This is what I suspect is what the warning was due to. IF they do actually get stuck, you can open the drive and release it by hand. Although I don't recommend opening up a drive like that, the choice is yours. (Obviously, I've done it, but...) al -- Al. Michielsen, Mechanical & Aerospace Engineering, Syracuse University InterNet: amichiel@rodan.acs.syr.edu amichiel@sunrise.acs.syr.edu Bitnet: AMICHIEL@SUNRISE