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jsofsky

How does the BIOS identify an IDE drive??

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Hey all,

I'm trying to run down a problem (much) more completely described in "Is my 75 GXP Dying" below. During an unrecoverable write problem in Win2000, a warm(push the switch) reset results in the hard drive not being identified by the BIOS and a 'boot failure' error. A powerdown results in the drive being seen and a normal boot of windows. I just installed an unformatted 60GXP as a slave device in preparation for a format using Partition Magic. On bootup it is NOT seen by the BIOS, but is seen by Win2000 and the VIA IDETool.

How and why does the BIOS identify an IDE disk? Motherboard is an ASUS A7Pro and the drives are attached to the internal IDE connectors.

Jack

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In the autodetect mode the BIOS reads the drive's firmware.

In the manual mode you have to provide the details yourself.

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There's two basic ways the BIOS gets the information describing the hard disk. That is, either the BIOS asks the drive for the information, or it stores the information in the CMOS.

Most modern BIOS can send a drive enquiry command to the drive, and read back the details of the disk, so it's detected each time you boot.

If your 75GXP is having problems, it's possible that the internal firmware on the 75GXP is busy trying to sort itself out, leading to the enquiry command failing, as the drive never responds or never clears the busy flag.

Win2000 and some other applications don't ask the BIOS for the information. Instead, they go and perform the same discovery that the BIOS would perform, which is why drives not in the BIOS are picked up by Win2K.

AidanII

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Some of the new motherboards dont do it each time they boot. Some motherboards only check the EIDE bus at user request only. I dont know why this is so but it is (my current board is like this, its a MSI KT266)

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How does the BIOS recognize an IBM hard drive????

By the grinding and screaching sounds it makes :lol:

Sorry, couldn't resist.

Bozo :D

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the people trying to be helpful are not familier with your problem. i am. i have witnessed it twice in the past two months.

the problem is that ibm hard drives are pieces of sh*t that will fail utterly, catastrophically, without reason or warning, when they are nearly new.

whereupon, your bios cannot even recognize the drive (instead of characters from the ascii character set, one sees smiles, spades, greek, junk).

i wouldn't use another ibm hard drive if someone gave it to me.

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I believe most modern BIOSes have an IDE delay that's normally set to 0. I'm not sure if this affects the ability to poll the drive's firmware, but it's worth a shot to set the delay to a higher number and see if that works.

Regards,

Tim

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