Hello!
I have a strange question about an old hard drive that I pulled out
of an old Pentium 1 computer. The hard drive was working fine, and
the computer was able to boot into Windows 95 fine.
Then I decided to run SpinRite6 to check if the hdd had any bad
sectors. SpinRite6 booted fine from a diskette and detected the
drive. Then it refused to do any kind of work from the drive and
claimed that the partition size was larger than the drive size
indicated in the computer bios.

The drive is a Western Digital caviar and its label indicates that it
has 2484 cyl; 16 heads; 63 sect; 1281.9 MB.

http://e.271828.p.31415.googlepages.com/s_IMG_2558.jpg

The computer auto-detected the drive as following: 2484; 16; 63; 1223
MB. This configuration was able to read the drive fine, but SpinRite
gives this:
http://e.271828.p.31415.googlepages.com/s_IMG_2558.jpg
http://e.271828.p.31415.googlepages.com/s_IMG_2561.jpg

Then I pulled the drive and stuck it in a newer Pentium 4 computer and
it detected it as follows: cyl :620; hds: 64; sectors: 63. Total
sectors 2502872
Spinrite ran fine.

When I stuck the drive back into the old computer I tried this
configuration and got 1221 MB.
http://e.271828.p.31415.googlepages.com/s_IMG_2560.jpg

The computer also booted up quite fine and made it into windows.
Spinrite still did not want to run on it and claims that only 619 cyl
are specified.
http://e.271828.p.31415.googlepages.com/s_IMG_2562.jpg
What is going on?

I have extensive experience with modern hardware, but this is my first
experience with such old hardware.

Can somebody please explain or clarify what is going on: How can the
harddrive be detected fine with 2 different configurations, which one
is the correct one, and why does Spin Rite read the drive on the newer
computer but refuses to read it on the old computer with either of the
2 configurations.


Thank you!