Date : Mon, 27 Dec 2004 02:28:35 +0100
From : John Kortink <kortink@...>
Subject: Re: ADFS and IDE drives
On 26 Dec 2004 23:55:45 +0000, Jonathan Graham Harston wrote:
>[...]
>
>Pete Turnbull wrote:
>>> I'm having some peculiar problems with IDE drives.
>>
>> integrated drive electronics and should be transparent. Does it
happen
>> with more than one drive?
>
>It happens with three of the five drives I've tried. I've
>fixed it by essentially doing a seek before each action.
Odd, but if that fixes it ... Does seem to indicate drive
peculiarities after all.
>[...]
>
>Sprow wrote:
>> The 1MHz bus is so slow my money would be dodgy drive!
>
>I think it's just one of those variable standards jobbies ;)
IDE ? No contest there ...
>John Kortink wrote:
>
>[...]
>
>> b) Drives not reacting to generic init sequence when
>> very specific delays between commands are observed
>
>I put the problem down to oddities due to the exact
>delays between commands. As good as explanation as any ;)
I meant in the init sequence only, not beyond that, but I
suppose there could be some issues related to the host
systems access speed (very, very low on 8-bit machines
for obvious reasons ;-).
>> c) Presence/absence of LBA mode
>
>Yes. Hmph. Reading the specs seems to specify that all IDE
>devices MUST support LBA.
Only since spec version X (up to 7 or so now). Drives below
umpf hundreds of MB won't have LBA because it was unknown
and unneeded at the time ...
>Consequently, the first code I
>wrote used LBA, and would you know it, the drive didn't
>support it. Grrr. Although everyy drive I've tested
>supports "Specify Drive Geometry" which makes things a lot
>easier than trying to do divide-by-31 all the time. I
>just tell the drive to pretend it has 64 sectors/track
>and use nice fast and neat bit rotates.
Tricky so some extent. I'm not sure it was ever mandatory.
'Natural' geometry only, really. Others optional. But it's
a good thing it works.
John Kortink
--
Email : kortink@...
Homepage : http://www.inter.nl.net/users/J.Kortink