Hi,

> as to why it's 255 and not 256...the bios numbers things starting from
> 1 and 256 is a nine bit number.

No, it's only an 8 bit number.  And the bios does support head numbers
start from 0 up to 254, which gives 255 heads, where it could support
head number 255 as well.  Your argument does hold some merit for the
sector number though, as that does indeed start with 1.

> >Hmm, from your dump and the problem you're having, I infer that your
> >bios doesn't support the new method.  However, since all your partitions
> >start below the 8GB limit, this isn't your problem.  See below.
> 
> hmm...that doesn't make me feel happy.  i bought the laptop less than
> a month ago and it's supposed to be just about the top of the line
> kind of thing.  granted...the bios doesn't say copyright 2000 or
> anything, but it does mention 1999.

As you might take from the short note exchange with Frank after that
mail, my conclusion was a bit too hasty.  Your machine might as well
support it.

> >The numbers for the explicit cylinder/head/sector look quite odd, except
> >for the start of the first partition.  The numbers for start and size
> >look ok.
> 
> that's normal.  at least...that's what i expect and have always seen
> on disks larger than ~500 megs.

No, that's not normal.  The numbers do make sense normally, at least
if it's possible to represent the addresses within the 1024/255/63 limits.

> okay...i'll try that later tonight.  but that'll just write the same
> stuff back to the disk, no?

No, the procedure I described will recompute the explicit cylinder/head/
sector numbers from the start and size numbers.  And those are used for
booting a partition...

> and it probes as:
> 
>    wd0: 11513 MB, 16383 cyl, 16 head, 63 sec, 512 bytes/sect x 23579136 sectors
> 
> but those numbers don't multiply together very well.  the 23392 number
> that i've got in my disklabel is what freebsd told me.

The 16383 cylinders is another limitation for ide disks (I think), which
is overcome by another innovation in ide access methods.  It doesn't however
have a direct relation to the bios limitation.

> is there any way to test this, short of watching the boot manager fail
> and guessing?  could i smack together a small assembly program that
> tries to use this "new method" and see?  something that could test
> things like this might be a "very good thing".

If you're adventurous, I can send you the procedure to do this
from within M$dos debug.  I'd have to dig it up first though.  Just
let me know (in private mail).

Ciao,
Wolfgang
-- 
ws@TooLs.DE     Wolfgang Solfrank, TooLs GmbH 	+49-228-985800