Peter L. Peres wrote:
>
> On Mon, 12 Oct 1998, James Cameron wrote:
>
> > Peter L. Peres wrote:
> > > On Sat, 10 Oct 1998, Chris Corben wrote:
> > > > Has anyone out there any clues to interfacing a PIC to an IDE
> > > > hard-disk?
> > > I did that for a Conner 20,40,60,80 MB laptop drive(s) with a PIC 16C64
> > > some time ago.
> >
> > How many I/O lines did you need to talk IDE?
> >
> > Possible with an 'F84?
>
> No, unless you like serial bus expanders very very much (4094/4021 etc) ;)
> I SUPPOSE that by daisy-chaining 3 F84s one could get there. I would not
> really really like to program such a thing, the C64 job was tough enough.
>
> > http://margo.student.utwente.nl/el/pc/hd-info/ide-tech.htm#IDETECH_004
>
> Leave that alone, get the ata IDE draft or full document off the web. I
> don't remember where, I have mirrored copies here.
>
> > Outputs: 6 (maybe less)
> > Inputs: 3 (one interrupt)
> > Bidirectional: 8 (or 16?)
>
> Make that 16 IO, 7 control outputs, one input == 24 pins + 1 power
> control. = 25 IO for this alone. You can economize one pin (RESET).
>
> > >From a quick reading of that page, I can see it would be a tough job.
> > Where would I find 512 bytes of RAM?  I'd have to add an external RAM
> > chip.
>
> The sector buffer(s) is(are) in the IDE drive... I did say something about
> using streaming algorythms in the PIC before on this theme ;)
>
> Peter

  One thought;  You could also, for slow data transfer rates at least,
look at the ValueStor type parallel port hard drive converters (Convert
an IDE or SCSI hard drive, or a CD-Rom Drive, to a Parallel port
interface.)  There's a Linux driver for both IDE models of these (I have
one old & one new version, ack!) - Fewer I/O lines would be necessary
for interfacing to a parallel port & so on - but, would too much speed
be required? (There's the rub <G>)

  I haven't really looked into this yet, but it's an interesting thought
at least!  (These units to require external power, usually an AC
adapter, I mean to hack that someday & make one mobile off a battery...)

  Parallel Port Linux drivers for this were off the Linux Parallel Port
Home Page at http://www.torque.net/parport/.

  Mark, mwillis@nwlink.com