Overcoming 8GB BIOS limit

[Zvi Netiv]

I am trying to do this without having to go to great lengths, e.g.
replacing the motherboard. If I was going to do that, why don't I just
use a different PC (I do have newer ones)?

I was explaining to Rod Speed (if this is his real name), not to you. I
understood exactly what you want. FWIM, I posted in this thread that I use
myself two 166 mhz PCs with the same limitations (BIOS handles only up to 8 GB
drive capacity, no boot option from CD), with 80 GB drives to their full
capacity and with NO boot overlay. See message ID

I have no reason not to want to use overlay.

Do you have a problem comprehending yourself? See next.

However, the software put out by Western Digital
says something about "by proceeding, all existing data will be lost".
I don't know whether this is just to warn you about the program having
the *ability* to reformat, or that just by clicking Next it will. I
also thought that the only overlay that would work was the software put
out by the manufacturer. Am I wrong?

There are two brands of boot overlays, the one originally designed by Micro
House Systems and known as EZ-BIOS, and Disk Manager, originally from Ontrack.
WD once used the latter and may be now using the EZ-Bios scheme, but I wouldn't
bet my life on it.

EZ-Bios *could be* installed without blanking the existing partition(s) (I have
done it in the distant past with the original Micro House program), but I
wouldn't bet that this is what the current setup program will do. As for DM,
this one will definitely irreversibly mess with the existing partition as it
needs to prepare an extra track on cylinder 0 for the overlay (the first
partition starts on head 2, cyl 0, sector 1, rather than on head 1 in ordinary
partitions) and overwrite critical data of the existing first partition! See
message <[email protected]> for additional reason why
you may not want to use an overlay. You may not have realized it, but no, you
don't want to, for not losing the existing partition.

The viable solution, with the limitations that you imposed (no new motherboard,
and use the entire capacity of the drive, without losing the existing data) is
an add-on IDE controller. What you look for is exactly the purpose for which
these boards have been made for. Install, start the computer, and configure the
entire drive the way you want, normally.

Regards, Zvi

 

[Rod Speed]

You didn't, but I doubt that the OP understood you differently.

Yeah, I could have said that more clearly.

He needs to change the motherboard for that, with a newer BIOS.

Yes, and in my opinion that makes a lot more sense than farting
around with a system that is so limited that it cant even boot a CD.
That change, likely for free, will likely fix the 8GB bios limit too.

This whole thread revolves on the OP insisting to have it his way,
with the old 166 mhz motherboard, and with no boot overlay.

He may however not have grasped the downsides of fighting
the limitations of a dinosaur that is that limited, or have realised
that something less limited may well be available for free.

 

[Rod Speed]

I am trying to do this without having to go to great lengths,
e.g. replacing the motherboard. If I was going to do that,
why don't I just use a different PC (I do have newer ones)?

That would make a lot more sense in my opinion, just
toss that particular dinosaur because its so limited.

I have no reason not to want to use overlay.

You do actually if you want to run linux on it as well.

However, the software put out by Western Digital says
something about "by proceeding, all existing data will be lost".
I don't know whether this is just to warn you about the program
having the *ability* to reformat, or that just by clicking Next it will.

They mean the data will certainly be lost.

I also thought that the only overlay that would work was
the software put out by the manufacturer. Am I wrong?

Yes, you are wrong. There are some overlays that will work
on all drives, but they arent cheap if you insist on a legal copy.

The ones supplied for free by the drive manufacturer will
usually only work on that manufacturer's drives and is
basically a cut down version of the full overlay thats
been deliberately changed to only run on their drives.

 

[Rod Speed]

Most chances are that there is no option to boot from CD with such old BIOS.

To the original poster: The idea of allocating the remaining 32 GB from
within
Windows isn't such a good one. First, it may not work, as it seems that you
have already discovered. Even if you succeed, then there are disadvantages
that
are worth considering.

First, you won't be able to access the higher partitions from DOS, something
that may be needed for emergency maintenance like cleaning from viruses, or
file
system repair.

Next, you should never attempt to resize partitions for the risk that you'll
corrupt anything. As a matter of fact, you'll probably lose the entire drive
content in the process if you do.

If what you are trying to do was so trivial, as some of the repliers make
believe, then what were boot overlays devised for?

They're just one way of getting around the bios limitation.

The Win route works fine for non boot drives.

The straightforward solution to your problem is an add-on EIDE
controller, as suggested by Joep and myself. They are cheap
($5 to $10) and resolve the problem without smart-ass work-arounds.

Makes a hell of a lot more sense to replace the entire system
with something that has the basics like boot from CD, for free.

 

[Rod Speed]

I had a few machines with that limitation, with OCTEK Rhino-6 and 10 boards,
with no BIOS update available. The following still keeps a couple of those
dinosaurs in service (one as fax, the other as CD burner) with 80 BG hard
drives.

If there is no BIOS update for your motherboard, then the straightforward
solution is to install an ATA card, e.g. Promise Ultra 33, 66, or 100 and
attach
the drive to the EIDE controller in lieu of the IDE channel.

The drive should be recognized to its full capacity on boot up, as well as the
existing 8 GB partition, and should let you allocate the remaining disk space
normally, either from DOS or Windows.

The detection of the drive is done by the EIDE card, the setting of the drive
in
the setup (BIOS) should be "not installed", to not waste time on futile search
during POST.

Makes a hell of a lot more sense to replace such a limited
dinosaur with one that can at least boot from CD, likely for free.

And there is no need to have a dedicated PC for fax and CD burning either.

 

[Folkert Rienstra]

I have been following this thread for some time too and am amazed by
the amount of misleading advice that has been posted to it, so far. ;-)

So now you have come to present the one and only solution.

If that method worked then you wouldn't need the current partition table data
because it's standard (for an 8 GB max size ME partition - type 12, 255 heads,
1024 cylinders, 63 sectors, which yields 16,450,497 of total sectors in the
partition). Besides, there is no problem even if you miscalculate the total
number of sectors in the partition as long as the type, active partition byte,
CHS of the partition beginning, and preceding sectors are correct.
The drive will boot on these and function normally.

From the above, and with the knowledge that the drive is 40 GB total size, you
can write an MBR image file, with the "synthetic" extended partition and write
it to block 0. But IMEO, it won't yield the expected result. In case you mis-
sed it in the OP later posts, FDISK only sees 8 GB of his drive from Windows.

And if you read his post properly you'd know that he will not be using Fdisk:
"I will create an extended partition and send it along with another
utility to create the extended partition *and logical drive*".

What will solve his "problem" is an add-on IDE controller card.

So that is your solution: Throw money at it.

 

[Folkert Rienstra]

Far more than that.

Nope, except for examination for a valid bootcode signature that
is all it does basically and then release control to the bootcode.
What happens next is that the bios is usually called back from the MBR
but it is free to execute any code that it wishes. Only problem with that
is that you cannot cram much meaningful code in less than a single sector
so you have to do at least one int13 call to load enough sectors that contain
self supporting code in order to load the rest of the OS, independent of BIOS.

The BIOS role doesn't end on loading block 0,

I never said it did, just that it loads block 0 and that what comes next can be
anything you choose. That anything you choose will probably call the bios to
aid loading code that makes it bios independent. (IF you were to whish that).

and boot overlays are the wrong example to prove your (wrong) assertion.

Nope. It proves that you can have a different MBR bootsector that executes
other code before it releases control to standard (whatever that is) MBR
bootsector code.

Just for the sake of the explanation,
suppose you managed to have a Linux partition on the subject drive, that starts
somewhere past 8 GB from the beginning of the drive, and made that partition
the boot (active) one.

What do you think will happen on startup?

With a bootoverlay and MBR bootcode that use Int13 extensions it will boot.
That's what I think. What do you think?

Will the drive boot? Not at all!

Depends obviously on the code in block 0 and what that code will do.
If it uses standard Int13h (calls) then nomatter how limited or unlimited that
bios is it will never be able to load an OS from beyond 8GB anyway, unless
the partition's bootsector is within 8GB (or whatever the bios's limitation is).

If it loads a bootoverlay that isn't a bios overlay but is just the code as used
by bios and runs without using interrupts to load linux then it will just work fine.
All that it needs is one int13h call to load sectors after sector 0.

After reading block 0 (the MBR) and the partition table contained in it, the
computer will attempt accessing the beginning of the partition flagged as
active, by aid of BIOS INT 13h.

Well, that obviously is not the case of
"What comes next can be anything you choose, as boot overlays prove".

It's not "the computer that will attempt accessing",
it is the code in the MBR that does.

In our case, int 13 will fail accessing anything past 8 GB and the boot
process will just hang.

Not in the case of using a bootoverlay or anything that you can come up with
to revert this kind of problem.

And it will still hang if the standard bootsector uses standard Int13h.

What boot overlays do is to replace the old int 13h routine with the newer
extended int 13h

Actually,
they replace any Int13h, standard or extended, with an Int13h extended.

so that access to the full capacity of the drive is available throughout the
startup process.

Just installing a bootoverlay doesn't give you access to beyond 8GB, for that
you need the proper bootcode in the MBR and partition bootsector as well.

Disk-access BIOS routines are replaced by the
OS only *after* their substitute is loaded.

If bypassing the BIOS would be that simple ("one call") then boot overlays
wouldn't need to be about 30 blocks (sectors) long.

You obviously didn't read the next sentence properly.
I said one *extra* call. One call can read 256 sectors
if necessary, so 30 sectors is actually a piece of cake.

Correct.

Nope, except for maybe 1 call to the BIOS to load and startup your own bios
independent code.
They don't need the BIOS to load the system, they *use* it to load the system.
That's different.

BIOS accessible definitely!

Only if it uses that.

NT/W2K/XP are BIOS independent too.

So is Win9x/ME.
What varies it to what extend the bootup process is using the
bios and where it stops using it.

Yet they all do need the BIOS to start up, on i386 hardware!

So "bios independent" is completely meaningless in this regard.

 

[Zvi Netiv]

Nope, except for examination for a valid bootcode signature that
is all it does basically and then release control to the bootcode.

You obviously have no clue on the internals of boot overlays, or of boot
viruses, that basically work the same way as boot overlays.

What happens next is that the bios is usually called back from the MBR
but it is free to execute any code that it wishes. Only problem with that
is that you cannot cram much meaningful code in less than a single sector
so you have to do at least one int13 call to load enough sectors that contain
self supporting code in order to load the rest of the OS, independent of BIOS.
Nearly.


I never said it did, just that it loads block 0 and that what comes next can be
anything you choose. That anything you choose will probably call the bios to
aid loading code that makes it bios independent. (IF you were to whish that).

There is no need for so many words to say absolutely nothing. Unless you are
trying to confuse the readers with meaningless jabber.

Nope. It proves that you can have a different MBR bootsector that executes
other code before it releases control to standard (whatever that is) MBR
bootsector code.



With a bootoverlay and MBR bootcode that use Int13 extensions it will boot.
That's what I think. What do you think?

Every bozo could understand that I was referring to the *subject drive* in its
specific environment (limited BIOS). Where from will the MBR boot code take the
Int 13 "extensions" when all there is available at that stage are *legacy* (old)
Int 13 routines?

Depends obviously on the code in block 0 and what that code will do.
If it uses standard Int13h (calls) then nomatter how limited or unlimited that
bios is it will never be able to load an OS from beyond 8GB anyway, unless
the partition's bootsector is within 8GB (or whatever the bios's limitation is).

Correct, and this is the only answer to my question.

If it loads a bootoverlay that isn't a bios overlay but is just the code as used
by bios and runs without using interrupts to load linux then it will just work fine.
All that it needs is one int13h call to load sectors after sector 0.

Whom are you trying to impress with that far fetched sophistry?

Well, that obviously is not the case of
"What comes next can be anything you choose, as boot overlays prove".

You are now trying to present your blunder as being right. .

It's not "the computer that will attempt accessing",
it is the code in the MBR that does.

It's the CPU, silly, also known as the computer. The MBR code doesn't have the
least of processing capability of its own.

Not in the case of using a bootoverlay or anything that you can come up with
to revert this kind of problem.

A boot overlay doesn't make part of the case, and your bringing it here won't
hide the fact that you are trying to get out of that nonsense, unbruised.

And it will still hang if the standard bootsector uses standard Int13h.

Which is the correct and only answer to the case presented.

Actually,
they replace any Int13h, standard or extended, with an Int13h extended.

Thank you for making that clear, but that was my line.

Just installing a bootoverlay doesn't give you access to beyond 8GB, for that
you need the proper bootcode in the MBR and partition bootsector as well.

Smart assing again? FWIM, setting the MBR loader is part of the installation
process of the boot overlay, as well as making provisions for the partition's
boot sector. FWIM, the boot sector code used with boot overlays is exactly the
same as without them, and doesn't require special attention when installing a
boot overlay. The one with EZ-bios even is at the same location (at CHS 011, by
default), only Disk Manager requires a special location for the boot sector, at
021, for the default.

You obviously didn't read the next sentence properly.
I said one *extra* call. One call can read 256 sectors
if necessary, so 30 sectors is actually a piece of cake.

You remind me a joke: A guy was told that his wife is sleeping with all men in
town. His reaction was: "Some town, just 500 men!".

Nope, except for maybe 1 call to the BIOS to load and startup your own bios
independent code.

Smart assing again, and ignoring the parameters of the case: Your own bios
independent code is located past the 8 GB limit and is inaccessible after your
"one Int 13 call" in the MBR. Full stop.

They don't need the BIOS to load the system, they *use* it to load the system.
That's different.

Smart assing again.

Only if it uses that.

There is nothing else to use at this stage, given the case parameters.

So is Win9x/ME.
What varies it to what extend the bootup process is using the
bios and where it stops using it.


So "bios independent" is completely meaningless in this regard.

It took you long to admit that.

Regards, Zvi

 

[Zvi Netiv]

Makes a hell of a lot more sense to replace the entire system
with something that has the basics like boot from CD, for free.

I suppose you meant that booting from CD is free. If you know where to get
newer boards for free, then let me know. There are a couple that I would be
glad to replace, if they are free.

Regards

 

[Zvi Netiv]

"Zvi Netiv" <support@replace_with_domain.com> wrote in message

And there is no need to have a dedicated PC for fax and CD burning either.

A few reasons for dedicated fax PC:

1. Cheaper on maintenance. No ink cartridges, no periodical cleaning. Printing
is done with the shared heavy duty printer.

2. One fax serves all employees.

3. Allows retrieving incoming faxes from remote, when away from office, through
VPN.

4. Ideal storage solution (80 GB drive), which is available to all users.

5. Doesn't lose incoming faxes when the secretary forgot to load paper, or there
was a power break and memory was dumped.

6. Quality. Faxes to/from computer are free from streaks and spots that haunt
optical faxes.

And there is more ...

Regards, Zvi

 

[Eric Gisin]

I suppose you meant that booting from CD is free. If you know where to get
newer boards for free, then let me know. There are a couple that I would be
glad to replace, if they are free.

You can add CD boot support via a boot manager:
http://btmgr.sourceforge.net/about.html

 

[Rod Speed]

I suppose you meant that booting from CD is free.

Nope, that what the extreme dinosaur that cant even boot
from a CD is replaced with will usually be free too when its
still an older discarded system that can at least boot from a CD.

If you know where to get newer boards for free, then let me know.
There are a couple that I would be glad to replace, if they are free.

There's plenty of PCs that can boot from the CD
that have been discarded and are available for free.

 

[Rod Speed]

A few reasons for dedicated fax PC:

Nope. These are reasons for using a PC for fax,
NOT for having a single PC dedicated to JUST faxing.

1. Cheaper on maintenance. No ink cartridges, no periodical
cleaning. Printing is done with the shared heavy duty printer.

2. One fax serves all employees.

3. Allows retrieving incoming faxes from remote,
when away from office, through VPN.

4. Ideal storage solution (80 GB drive), which is available to all users.

5. Doesn't lose incoming faxes when the secretary forgot to load
paper, or there was a power break and memory was dumped.

6. Quality. Faxes to/from computer are free from
streaks and spots that haunt optical faxes.

And there is more ...

Nope, not for having a PC dedicated to JUST faxing.

It makes a hell of a lot more sense to have that PC do more
than JUST faxing, and then there isnt any need to use such
a limited old dinosaur that cant even boot of the CD etc.

 

[Zvi Netiv]

You can add CD boot support via a boot manager:
http://btmgr.sourceforge.net/about.html

Thanks for the link, Eric.

To the OP: In case you want to try Smart BootManager (it's free) with your
board, note that it installs the same as a boot overlay (modifies the MBR loader
but not the partition table) and requires reinstallation after setting up a new
version of Windows. Adding SBTM to an IDE add-on controller provides relieves
both limitations (drive capacity and booting of CD) of your old P166 board.

Regards