Post by thread:Hard Disk Control

Hello, I am trying to control the rotation of an IDE hard drive using signals to be generated by a PIC. I have tried looking at the pinout of the IDE hard drive, but can't tell what of kind of signals are needed to make the disk motor rotate on and off by sending data from a PIC. I don't need to control the head or read any data. Only to rotate the motor continously when I send it the signals. Can anyone help if you have the information? Thanks. Mike _________________________________________________________ Do You Yahoo!? Get your free @yahoo.com address at http://mail.yahoo.com

Mike, An IDE drive has an on-board controller that handles all the seeking, etc... You don't really have any direct control over the motor through the IDE connector. I guess you could continuously read sectors in a circle, but even when you stop reading, there's no guarantee the drive will stop spinning. Maybe you should just get a stepper motor? Cheers, Ben mike wrote: {Quote hidden}> > Hello, > > I am trying to control the rotation of an IDE hard > drive using signals to be generated by a PIC. > > I have tried looking at the pinout of the IDE hard > drive, but can't tell what of kind of signals are > needed to make the disk motor rotate on and off by > sending data from a PIC. I don't need to control the > head or read any data. Only to rotate the motor > continously when I send it the signals. > > Can anyone help if you have the information? > > Thanks. > > Mike > > _________________________________________________________ > Do You Yahoo!? > Get your free @yahoo.com address at http://mail.yahoo.com

mike wrote: > > Hello, > > I am trying to control the rotation of an IDE hard > drive using signals to be generated by a PIC. > > I have tried looking at the pinout of the IDE hard > drive, but can't tell what of kind of signals are > needed to make the disk motor rotate on and off by > sending data from a PIC. I don't need to control the > head or read any data. Only to rotate the motor > continously when I send it the signals. > > Can anyone help if you have the information? > > Thanks. > > Mike Best I can figure is to use a Laptop drive, where you can switch motor power on/off separately from drive control electronics power (Pin 44 vs. pin 42 on the connector.) Maybe if you told us more? <G> Mark

Hi Mike, Like Ben Stragnell pointed out, the HD's logic controls the stepper motor. If you want, maybe you could do a relay/transistor combo to cut off the +5V and +12V? (Or just the +12V, this is the motor(s) supply) You won't find the motor control on the IDE pinouts. Then you could ask "well then how does windoze cut off the HD's?" Well, there are CCB (or CBC?) commands that take care of this. If you want, I can try to get ahold of the latest IDE spec for this. Take care, Tim Hamel In a message dated 6/22/99 11:30:13 AM Pacific Daylight Time, .....lktronKILLspam@spam@YAHOO.COM writes: {Quote hidden}> Hello, > > I am trying to control the rotation of an IDE hard > drive using signals to be generated by a PIC. > > I have tried looking at the pinout of the IDE hard > drive, but can't tell what of kind of signals are > needed to make the disk motor rotate on and off by > sending data from a PIC. I don't need to control the > head or read any data. Only to rotate the motor > continously when I send it the signals. > > Can anyone help if you have the information? > > Thanks. > > Mike > > >

Ben Stragnell wrote: > An IDE drive has an on-board controller that handles all the seeking, > etc... You don't really have any direct control over the motor through > the IDE connector. You may notice that later versions of Win95 and Win98 provide power- saving functions including shutting down the IDE drive. These will be provided via specific numeric *commands* to the drive via the ATAPI bus. You'll need to look into the ATAPI documentation. I suspect it applies to later model drives, though for all I know, even early ones may have had that latent capability. A similar situation applies to low-level format. This is performed automatically on most cached drives, and could not be commanded AFAIK on earlier ones (a very useful "idiot-proofing" feature). Later BIOS seem however to offer such a feature for no obvious useful reason. -- Cheers, Paul B.

Hello, Thanks to everybody for your helpful answers. I have the PC power connector (the 12v/5v +grounds) plugged into the hard drive. Nothing connected to the IDE plug. Then when I turn on the power, the motor spins up and after a short run stops. When I ground the RESET pin (pins 1 and 2 ) the drive spins and then stops again. I have one drive, a Quantum ST64A011 which will spin continously, as long as the pins are shorted. But other drives I have do not. I tried a Seagate laptop hard drive, and applied +5v to the motor pin and logic pin, it wiggles a bit and then stops. Strange? Perhaps as Tim Hamel suggests, I need to send CCB or CBC commands to the drive, but then waht is the digital equivalent and which pins is the signal sent to? In any case, I want to use a hard drive because I am doing an optics experiment and the hard drives by their design are very highly balanced, whereas if I were to get a servo, I would need to balance everything and it would be ... Thanks again. Any further suggestions or help will be appreciated. Mike --- Tim Hamel <IMDNICE12KILLspamAOL.COM> wrote: {Quote hidden}> Hi Mike, > > Like Ben Stragnell pointed out, the HD's logic > controls the stepper motor. > If you want, maybe you could do a relay/transistor > combo to cut off the +5V > and +12V? (Or just the +12V, this is the motor(s) > supply) You won't find the > motor control on the IDE pinouts. Then you could > ask "well then how does > windoze cut off the HD's?" Well, there are CCB (or > CBC?) commands that take > care of this. If you want, I can try to get ahold of > the latest IDE spec for > this. > > Take care, > > Tim Hamel > > In a message dated 6/22/99 11:30:13 AM Pacific > Daylight Time, > .....lktronKILLspam.....YAHOO.COM writes: > > > Hello, > > > > I am trying to control the rotation of an IDE > hard > > drive using signals to be generated by a PIC. > > > > I have tried looking at the pinout of the IDE > hard > > drive, but can't tell what of kind of signals are > > needed to make the disk motor rotate on and off > by > > sending data from a PIC. I don't need to control > the > > head or read any data. Only to rotate the motor > > continously when I send it the signals. > > > > Can anyone help if you have the information? > > > > Thanks. > > > > Mike > > > > > > > _________________________________________________________ Do You Yahoo!? Get your free @yahoo.com address at http://mail.yahoo.com

One thing that comes to mind, what IF the drive is so quiet that after it spins up you think it's spun down? <g> The spin down could be a result of the drives uControllers shutting it down for power savings. I was able to acquire a copy of the ATA Interface Spec. You can read (err, skim through it). It's a few hundred pages, so you'll definetely have to refer to the TOC. Specifically, the ones about the ATA Command Set. These commands can be sent via the lower bits (D0-D7, 8-bits) instead of using all 16 lines. Anyways, here's the link to the spec. ftp://fission.dt.wdc.com/pub/standards/x3t13/project/ The one you want is d1321r1a.pdf or d1321r1a.zip The ZIP file contains the spec in DOC form. Tim Hamel In a message dated 6/22/99 1:24:41 PM Pacific Daylight Time, EraseMElktronspam_OUTTakeThisOuTYAHOO.COM writes: {Quote hidden}> Hello, > Thanks to everybody for your helpful answers. > > I have the PC power connector (the 12v/5v +grounds) > plugged into the hard drive. Nothing connected to the > IDE plug. Then when I turn on the power, the motor > spins up and after a short run stops. > > When I ground the RESET pin (pins 1 and 2 ) the drive > spins and then stops again. I have one drive, a > Quantum ST64A011 which will spin continously, as long > as the pins are shorted. But other drives I have do > not. I tried a Seagate laptop hard drive, and applied > +5v to the motor pin and logic pin, it wiggles a bit > and then stops. > > Strange? > > Perhaps as Tim Hamel suggests, I need to send CCB or > CBC commands to the drive, but then waht is the > digital equivalent and which pins is the signal sent > to? > > > In any case, I want to use a hard drive because I am > doing an optics experiment and the hard drives by > their design are very highly balanced, whereas if I > were to get a servo, I would need to balance > everything > and it would be ... >

----- Original Message ----- From: Andy Kunz <supportspam_OUTMONTANADESIGN.COM> To: <@spam@PICLISTKILLspamMITVMA.MIT.EDU> Sent: Tuesday, June 22, 1999 8:26 PM Subject: Re: Hard Disk Control {Quote hidden}> >etc... You don't really have any direct control over the motor through > >the IDE connector. I guess you could continuously read sectors in a > > You have to command the controller to power down the motor. > > Andy > > ================================================================== > Andy Kunz - http://www.montanadesign.com - KILLspamandyKILLspammontanadesign.com > Life is what we do to prepare for Eternity > ================================================================== Has anyone written any code for the 16c84 for any ide hard drive control. It could come in handy for cd-rom also. I'm about to use a multidisk cd rom ffor audio only, and was about to control it by infra red, but if I could do it by ide it would make life much easier. John Perkinton.>