From: Hans-Bernhard Broeker Newsgroups: comp.os.msdos.djgpp Subject: Re: direct hard drive controll? Date: 10 Jul 2000 16:28:02 GMT Organization: Aachen University of Technology (RWTH) Lines: 23 Distribution: world Message-ID: <8kctii$joa$1@nets3.rz.RWTH-Aachen.DE> References: <200007071558 DOT VAA00953 AT midpec DOT com> <1lpdms87iqsbt558fqotdrhb1krtmgao78 AT 4ax DOT com> NNTP-Posting-Host: acp3bf.physik.rwth-aachen.de X-Trace: nets3.rz.RWTH-Aachen.DE 963246482 20234 137.226.32.75 (10 Jul 2000 16:28:02 GMT) X-Complaints-To: abuse AT rwth-aachen DOT de NNTP-Posting-Date: 10 Jul 2000 16:28:02 GMT Originator: broeker@ To: djgpp AT delorie DOT com DJ-Gateway: from newsgroup comp.os.msdos.djgpp Reply-To: djgpp AT delorie DOT com Damian Yerrick wrote: > On Fri, 07 Jul 2000 21:03:30 GMT, nunnayod AT mbiz DOT nez (CaffineLady) > wrote: >> I don't want to read any data (infact the platter will probably be removed), >>and I need the operation to be fast because I need to switch between tracks >>really really fast (to move the mirror Im gonna glue to it back and forth). > Most modern hard drives use a voice coil to move the head. If you > just want to move a mirror real fast, why not program the voice coils > yourself with a sound card? I second this suggestion. If the hard drive is even remotely modern, it won't move the heads at all without the platters in, anyway. Modern drives don't use stepper motors any more to position their heads. Do successfully find discrete tracks with their continuous actuator, they need special information on the platters ('servo information'). This implies that without the platters, the head doesn't know where it is, and no command from the controller will reproducibly position it anywhere but at the emergency stoppers :-( -- Hans-Bernhard Broeker (broeker AT physik DOT rwth-aachen DOT de) Even if all the snow were burnt, ashes would remain.