Re: CVS commit: src/sys/dev/ata

[Warner Losh <imp%bsdimp.com@localhost>]

On Oct 16, 2011, at 9:25 PM, John Nemeth wrote:

> On Feb 25,  1:28pm, Wolfgang Solfrank wrote:
> } Jonathan A. Kollasch schrieb:
> } > On Wed, Oct 05, 2011 at 10:25:52AM +0200, Manuel Bouyer wrote:
> } >> On Wed, Oct 05, 2011 at 03:40:18AM +0000, Jonathan A. Kollasch wrote:
> } >>> Module Name:    src
> } >>> Committed By:   jakllsch
> } >>> Date:           Wed Oct  5 03:40:18 UTC 2011
> } >>>
> } >>> Modified Files:
> } >>>         src/sys/dev/ata: wd.c
> } >>>
> } >>> Log Message:
> } >>> Limit wd(4) transfers to 128 (512-byte) logical sectors, as the 
> traditional
> } >>> MAXPHYS value has for at least the past decade.
> } >>
> } >> We should be able to go safely up to 256 sectors. Anything larger 
> requires
> } >> LBA48, which is not supported by some controllers.
> } >
> } > Do we know how a real ST506 or similar ancient drive would respond
> } > to such a command?
> } 
> } The ST506 was only a disk drive with no embedded controller logic.
> } So it wouldn't respond to such a command at all, as it doesn't even see it.
> } The command interface, after which the original ATA interface was modelled,
> } was that of the WD1010 disk controller, to which this and similar drives
> } would attach.  You would tell the controller the cylinder/head/sector
> 
>     And, I very much doubt there were any PCI versions of these
> controllers since IDE came out well before the end of the ISA era.
> Worrying about drives that old is pretty much pointless.  Even if you
> could find one, it is very likely to be non-functional (these weren't
> exactly high quality devices).

You can still buy ESDI devices (that are compatible with the ST506 interface).  
Ebay has them from $35 to $535!  Sizes up to 750MB.

I was able to find ISA and Micro Channel ESDI cards.  I didn't see EISA or PCI 
ones either on Ebay or Google...

So I think you may be right about PCI.  IIRC, the only machines that had these 
were 386 boxes that weren't lucky enough to have IDE (the frankenstein machines 
of the time, since by then multi-function cards with IDE were the common 
solution) and some of the 68k early home machines (Atari and Amiga maybe) and 
sun 3's.

Warner