Newsgroups: comp.misc Path: utzoo!utgpu!news-server.csri.toronto.edu!torsqnt!tmsoft!robohack!contact!slaurel From: slaurel@contact.uucp (David Maxwell) Subject: Re: Installing HDs upside-down Organization: Contact Public Unix BBS. Toronto, Canada. Date: Sun, 28 Apr 91 04:59:17 GMT Message-ID: <1991Apr28.045917.14294@contact.uucp> References: <1991Apr21.184024.13484@ecst.csuchico.edu> In mikeg@c3.c3.lanl.gov (Michael P. Gerlek) writes: >In article <1991Apr21.184024.13484@ecst.csuchico.edu> > ekrimen@ecst.csuchico.edu (Ed Krimen) writes: >> I always had the impression that installing HDs upside-down was bad. Then >> so I'm assuming upside-down drives aren't a problem. >> Is it preferable to install hard drives upside-down?! >Doesn't make a (bit) of difference, because the bits are stored on the >disk vertically, and an upside-down 1 or 0 is still readable as a 1 or >0 - ones and zeros are vertically symmetrical. :-) :-) >Of course, you may wind up reading all your files backwards >(endianness, et al)... Well, while the positioning of a drive may have no effect on the magnetic storage system used, because everything is relative to the position of the drive, there is another matter. Hard drives contain a disk which spins constantly, and at high speed. These two facors are part of the reason hard drives are so fast. 1) No wait for spin-up time during each disk access (As per floppy). 2) The disk is more durable, and encased in a dust/fingerprint/moisture-proof box, which means that the magnetic surface is more reliable and is one factor which allows the data to be read at the higher rotational speeds. Numbers one and two combine to set up a constant, fairly strong gyroscope, so moving the drive (aside from in the plane of rotation) while it's on is a bad idea. Try holding a gyroscope and turning it in any direction (Not in the plane of rotation) and feel the resistance. Imagine the gyroscope spinning much faster, and the resistance as pressure on the surface of your hard disk's platter. Not good. I'm not a physics major, but I've been told that the best positions for the drive are 90 deg angles, (I justify this by reminding myself that the Earth is spinning too. (Maybe hardrives should only be mounted sideways in positions where they face north or south? :-) ) ) So aside from that, remind yourself that hardcard makers mount drives sideways daily, but that the hard drive manufacturers make them with a side generally considered up. If it was better for your hardrive to be upside down, or sideways, wouldn't the manufacturer have called a different side 'up'. (I have two hardrives mounted sideways in my machine, one on it's left, on it's right.) David Maxwell P.S. Would some kindly physics major like to discuss gyroscopic forces in terms of hard drives? -- Worf: I protest! I am NOT a merry man! (Qpid) slaurel@contact