CHS or LBA?

BIOS update, EIDE card, or overlay software? (FAQ Hard disk recognition)
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KachiWachi
The New Guy
Posts: 1451
Joined: Fri Mar 29, 2002 10:32 pm
Location: Pennsylvania, USA

Hi Again...

I have a WD AC28400 8.4GB drive here...why would a BIOS prefer to set it up in CHS (LARGE) mode rather than in LBA mode? I mean this by using the *Auto Mode* and not using the *IDE Detection* screen, where it does pick LBA as the recommended setup.

If the drive was set up in CHS, then I changed the BIOS to LBA, would I lose the data on the drive?

Thanks as always...
edwin
The Hardware Archivist
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Location: Netherlands
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You wouldn't loose the data but you cannot read it either.

Can't quite think of a reason other than a buggy bios. Set it for LBA.
edwin/evasive

Do not assume anything

System error, strike any user to continue...
Rainbow
The UniFlasher
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Location: Slovakia
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I've seen that on some early Award v4.50 BIOSes.
Patched and tested BIOSes are at http://wims.rainbow-software.org
UniFlash - Flash anything anywhere
KachiWachi
The New Guy
Posts: 1451
Joined: Fri Mar 29, 2002 10:32 pm
Location: Pennsylvania, USA

Well, here's the story...

I had originally setup the drive on my girlfriends now defunct SuperMicro P5STE with an AMI BIOS (see other post on that) and it set it up as LARGE (why I don't know). So when I moved it over to her new(er) computer (Biostar M5ATC w/ patched BIOS from here), it also seemed to set it up as LARGE, but I couldn't see any data (as edwin mentioned). Well, I had been playing around with the 40GB and this guy attached to the motherboard (see other post) so I thought maybe something got corrupted somehow, and I set Norton NDD to work on it. Well, basically I didn't notice that NDD was showing the drive to be a 15.6GB HD and not an 8.4GB, and proceeded to let it try to *fix* things... BIOS was still reporting 8.4GB so why would I look??

UGH!!!

Well, to make a long story short, NDD *fixed* it alright...

So now I go and reformat the thing to start over...things seemed to go OK...so I reboot, it still detects LARGE, but the format didn't hold. So I do this 3 times...zip...so now I'm thinking her HD went bad. NDD was saying the Boot Record was all messed up, and that there were bad sectors on the drive. When it tried to repair it, NDD would crash with a runtime error.

Well, on a whim I decided to nuke (fdisk) the partition tables and really start over... As soon as I did that, and rebooted, the M5ATC then set it up in LBA. Is that information stored on the drive somewhere (whether it is setup in NORMAL, CHS, or LBA)?? After fdisk and format, things held and no bad sectors were found.

In any case, this will give me a clean start (yet again for her...lol).

Any thoughts on what happened?
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