Re: Very old IDE hard drive (240 MB) detected as 1.1 TB

From: Sergei Shtylyov
Date: Sat Feb 14 2009 - 10:55:06 EST


Hello.

Maciej W. Rozycki wrote:

It has the current capacity in words 57-58 swapped:

/dev/sdb:
0c5a 037f 0000 000a 8723 0275 0037 0030
000a 0000 2020 2020 2020 2020 2020 424d
3948 4d31 5020 2020 0003 0040 0004 302e
3336 2020 2020 436f 6e6e 6572 2050 6572
6970 6865 7261 6c73 2032 3430 4d42 202d
2043 5033 3032 3534 2020 2020 2020 8010
0000 0001 0000 0200 0202 0001 037f 000a
0037 0007 82da 0000 0000 0000 0000 0000


It must be 82da 0007, not 0007 82da.
IIRC, the IDE core doesn't trust the value reported in these words
..

That's right. I wrote the IDE code that way
*specifically* due to a (different) Conner drive
I had here at the time.

It happened for some Maxtor drives too. The reason is the ATA-1 spec was

And with Fujitsu ones too. IIRC, the one I encountered (10+ years ago) had something like 0000 c000 there -- which in no way was related to its real capacity.

not explicit about how words 57 and 58 were meant to be ordered and some manufacturers interpreted it one and some the other way.

However, the drive vendors should've really thought better before reporting capacity in *middle-endian* format. :-)

Maciej

MBR, Sergei


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