Originally Posted By: brianl703
Originally Posted By: OVERK1LL
The drive would detect, but none of the information was accessible. Switching the BIOS on the new board to access the drive via LARGE fixed the issue.
Windows 98/XP/Vista/7 does not use INT13H services to access the drive.
After it boots, it could not care less what mode is set in the BIOS to access the drive, it talks directly to the hardware.
The following talks about NT 4.0, but verifies what I said:
http://support.microsoft.com/kb/q224526/
I have a laptop that doesn't support larger than 8GB drives due to a BIOS limitation. To work around it, I installed Windows 98 on an 8GB partition at the start of a 40GB drive (necessary to make sure that any system files necessary for the boot process remain accessible), then made several more partitions to use the rest of the space. Said partitions were inaccessible from DOS, but Windows 98 had no problem getting to them.
This is similar to the way you create a boot partition in Linux that is within the first 504MB of the drive, then it doesn't matter what kind of translation the BIOS does, it still boots because the kernel boot files are stored in an area of the drive that is accessible no matter whether the BIOS is set to LBA, CHS, or LARGE. After the kernel is loaded, the BIOS translation settings are moot.
Before I started doing that, yes, I had problems where a Linux drive wouldn't always boot anymore when moved from one motherboard to another. Those problems were why I started setting up the boot partition like that. After I did that, never a problem again.
I am aware of the article, but I imagine it is due to hardware or software limitations, or how things are translated... as I HAVE had issues (I'm seriously not hallucinating here) where the scenario I depicted has occurred.
It is similar to the "Windows XP doesn't care if your BIOS doesn't support drives over 137GB, it will still see the entire drive" scenario.
The vast majority of the time... It doesn't matter. But there have been times (and I honestly don't know the cause, perhaps it is a controller limitation? I haven't bothered researching it) where a 160GB drive for example STILL shows as 137GB in the partition creation screen for setting up Windows. It takes a BIOS update to fix the problem in this instance.
Yet on other systems, with the same problem, Windows setup shows the entire drive.
EDIT:
I wonder, if perhaps due to a controller limitation or a compatibility issue (resolvable with a driver?) that there are scenarios where the OS IS in fact forced to access the drive through the BIOS and forced to use whatever translation method it is setup for.
I honestly don't know other than I've had the issue on more than one occasion and the scenario typically involves a drive from an older system, usually Windows 98, being put in a newer Windows XP box.
The partitions are visible. In some cases the data is too. But none of the data is actually usable (is corrupt when you try to view it) but this is fixed by matching the BIOS settings to what they were for the drive in the old system.
