In trying to move to a new hard drive, I have noticed that
my first partition doesn't start right after the MBR. There
seem to be a few sectors after the MBR that BootMagic is
using for something. Can anyone point me to what the format
of Track 0 is?

- Tim

--

"Spammay Blockay" <(E-Mail Removed)> wrote in message
news:bnoou8$fj5$(E-Mail Removed)...
> In trying to move to a new hard drive, I have noticed that
> my first partition doesn't start right after the MBR. There
> seem to be a few sectors after the MBR that BootMagic is
> using for something. Can anyone point me to what the format
> of Track 0 is?
>
> - Tim
>
> --
>

Sector 0 : MBR
Sector 1 - 63 : void, but indeed sometimes used by boot managers, drive
overlay software, virtual diskettes, virii, mbr backups etc. There's no
convention on how those tools that use track 0 behave.

--
Joep

In article <bbedd$3f9fe886$3eddca68$(E-Mail Removed)>,
Joep <j o e p @ d i y d a t a r e c o v e r y . n l> wrote:
>"Spammay Blockay" <(E-Mail Removed)> wrote in message
>news:bnoou8$fj5$(E-Mail Removed)...
>> In trying to move to a new hard drive, I have noticed that
>> my first partition doesn't start right after the MBR. There
>> seem to be a few sectors after the MBR that BootMagic is
>> using for something. Can anyone point me to what the format
>> of Track 0 is?
>>
>> - Tim
>>
>> --
>>
>
>Sector 0 : MBR
>Sector 1 - 63 : void, but indeed sometimes used by boot managers, drive
>overlay software, virtual diskettes, virii, mbr backups etc. There's no
>convention on how those tools that use track 0 behave.

Thanks! I did a Deja search after I asked, and saw you had
discussed this earlier, but this clarifies things nicely.

Also... I thought that each track usually has 63 sectors,
so track 0 would be sectors 0-62, right? Intuitively I'd
think 64 (power of 2, etc.), but all the documentation I read
says 63.

- Tim

--

"Spammay Blockay" <(E-Mail Removed)> wrote in message news:bnor3s$ht0$(E-Mail Removed)...
> In article <bbedd$3f9fe886$3eddca68$(E-Mail Removed)>,
> Joep <j o e p @ d i y d a t a r e c o v e r y . n l> wrote:
> >"Spammay Blockay" <(E-Mail Removed)> wrote in message
> >news:bnoou8$fj5$(E-Mail Removed)...
> >> In trying to move to a new hard drive, I have noticed that
> >> my first partition doesn't start right after the MBR. There
> >> seem to be a few sectors after the MBR that BootMagic is
> >> using for something. Can anyone point me to what the format
> >> of Track 0 is?
> >>
> >> - Tim
> >>
> >> --
> >>
> >
> >Sector 0 : MBR
> >Sector 1 - 63 : void, but indeed sometimes used by boot managers, drive
> >overlay software, virtual diskettes, virii, mbr backups etc. There's no
> >convention on how those tools that use track 0 behave.
>
> Thanks! I did a Deja search after I asked, and saw you had
> discussed this earlier, but this clarifies things nicely.
>
> Also... I thought that each track usually has 63 sectors,
> so track 0 would be sectors 0-62, right? Intuitively I'd
> think 64 (power of 2, etc.), but all the documentation I read
> says 63.

Thats just because the total is 64, the MBR takes one.

That is the convention from the controller on the PC/AT. The register is 6
bits, but sectors start at 1 so there are only 63.

"Spammay Blockay" <(E-Mail Removed)> wrote in message
news:bnp79p$1kt$(E-Mail Removed)...
|
| Not so -- my partitioning software and other drive-control
| software, says "63 sectors/track". So they're ignoring the
| 1st sector of ALL tracks? That doesn't sound right.
|

In article <bnou01$14amu2$(E-Mail Removed)>,
Rod Speed <(E-Mail Removed)> wrote:
>
>"Spammay Blockay" <(E-Mail Removed)> wrote in message news:bnor3s$ht0$(E-Mail Removed)...
>> Also... I thought that each track usually has 63 sectors,
>> so track 0 would be sectors 0-62, right? Intuitively I'd
>> think 64 (power of 2, etc.), but all the documentation I read
>> says 63.
>
>Thats just because the total is 64, the MBR takes one.

Not so -- my partitioning software and other drive-control
software, says "63 sectors/track". So they're ignoring the
1st sector of ALL tracks? That doesn't sound right.

- Tim

--

Spammay Blockay wrote:
> In article <bnou01$14amu2$(E-Mail Removed)>,
> Rod Speed <(E-Mail Removed)> wrote:
>
>>"Spammay Blockay" <(E-Mail Removed)> wrote in message news:bnor3s$ht0$(E-Mail Removed)...
>>
>>>Also... I thought that each track usually has 63 sectors,
>>>so track 0 would be sectors 0-62, right? Intuitively I'd
>>>think 64 (power of 2, etc.), but all the documentation I read
>>>says 63.
>>
>>Thats just because the total is 64, the MBR takes one.
>
>
> Not so -- my partitioning software and other drive-control
> software, says "63 sectors/track". So they're ignoring the
> 1st sector of ALL tracks? That doesn't sound right.
>
> - Tim
>

On modern HDs, the logical sector address (C/H/S) is translated
by the HD into physical C/H/S; necessary because the number of
sectors/track is not constant. 63 sectors/track has been fiction
for years.
--
Cheers, Bob

In article <tjWnb.44966$ao4.104503@attbi_s51>,
Bob WIllard <(E-Mail Removed)> wrote:
>Spammay Blockay wrote:
>> In article <bnou01$14amu2$(E-Mail Removed)>,
>> Rod Speed <(E-Mail Removed)> wrote:
>>
>>>"Spammay Blockay" <(E-Mail Removed)> wrote in message news:bnor3s$ht0$(E-Mail Removed)...
>>>
>> Not so -- my partitioning software and other drive-control
>> software, says "63 sectors/track". So they're ignoring the
>> 1st sector of ALL tracks? That doesn't sound right.
>>
>> - Tim
>>
>
>On modern HDs, the logical sector address (C/H/S) is translated
>by the HD into physical C/H/S; necessary because the number of
>sectors/track is not constant. 63 sectors/track has been fiction
>for years.

I know that there may not be actually 63 sectors/track, but
I'm talking about what your standard boot manager program
(or any other software that writes to track 0) assumes about
track size. Since the OS's idea of the disk layout is that it
has 63 sectors/track, I'd think that's what boot managers, et. al.,
would also assume, and write to track 0 accordingly. Not so?

- Tim

--

In article <(E-Mail Removed)>,
Eric Gisin <(E-Mail Removed)> wrote:
>That is the convention from the controller on the PC/AT. The register is 6
>bits, but sectors start at 1 so there are only 63.

That makes sense -- I knew there had to be SOME reason
for it! :-)

I *had* read elsewhere about the whole historical problem of
trying to stuff larger and larger disk addresses into a
traditional CHS value, and somewhere read about the 6-bits
available for that value.

WHEN, I wonder, will we drop all this old DOS nonsense and go to
values that can encompass future huge disk (and other device)
sizes? 64-bit addresses or larger? And BIOSs that know about
that as well? And NO support for this stupid legacy?

*sigh*

- Tim

--

"Spammay Blockay" <(E-Mail Removed)> wrote in message news:bnpblq$7ph$(E-Mail Removed)...
> In article <tjWnb.44966$ao4.104503@attbi_s51>,
> Bob WIllard <(E-Mail Removed)> wrote:
> >Spammay Blockay wrote:
> >> In article <bnou01$14amu2$(E-Mail Removed)>,
> >> Rod Speed <(E-Mail Removed)> wrote:
> >>
> >>>"Spammay Blockay" <(E-Mail Removed)> wrote in message news:bnor3s$ht0$(E-Mail Removed)...
> >>>
> >> Not so -- my partitioning software and other drive-control
> >> software, says "63 sectors/track". So they're ignoring the
> >> 1st sector of ALL tracks? That doesn't sound right.
> >>
> >> - Tim
> >>
> >
> >On modern HDs, the logical sector address (C/H/S) is translated
> >by the HD into physical C/H/S; necessary because the number of
> >sectors/track is not constant. 63 sectors/track has been fiction
> >for years.

> I know that there may not be actually 63 sectors/track,
> but I'm talking about what your standard boot manager
> program (or any other software that writes to track 0)
> assumes about track size.

They just use that virtual 63 sectors per track number.

> Since the OS's idea of the disk
> layout is that it has 63 sectors/track,

Thats not right either. The OS mostly uses logical block numbers
where sectors are in effect numbered from the start of the drive.

63 sectors per track is just the virtual CHS number for S and
modern OSs dont do that much in terms of CHS values anymore.

> I'd think that's what boot managers, et. al., would
> also assume, and write to track 0 accordingly.

Yes, and there is no downside with just using the conservative number of
63 when only the first physical sector is quite rigidly defined as far as what
its used for and the rest of that track isnt in theory used at all in a formally
specified sense and the various boot managers/bios overlays/virtual boot
systems all basically do their own thing with the sectors in that track.

At most they attempt to not stomp on
other stuff using some of those sectors too.

> Not so?

Yes, but thats a different issue to what the OS does.