Re: Cylinder limits jumper for drives over 32GB

From: Andries.Brouwer@cwi.nl
Date: Sun Mar 26 2000 - 17:45:33 EST


> 0000 0000 0000 0000 0000 0000 0000 23a5

Thanks.

This afternoon I have played a bit with READ_NATIVE_MAX_ADDRESS
and SET_MAX_ADDRESS, and find for my 36.5 GB Maxtor the following:

(i) READ_NATIVE_MAX_ADDRESS works
[In CHS mode I get #cylinders mod 65536, in LBA mode the correct answer.]

(ii) SET_MAX_ADDRESS works whenever I want to set the max address
to anything at least 255 sectors from the end. So, as soon as I
have used SET_MAX_ADDRESS, 255 sectors or 130kB is gone.
A reboot does not suffice to get this back, but after a power cycle
the disk has full capacity again.

(I wonder whether this is a bug. The way I read the ATA-5 spec
it should be possible to do SET_MAX_ADDRESS to the address
gotten back from READ_NATIVE_MAX_ADDRESS.)

A side effect of SET_MAX_ADDRESS is that the current geometry
is reset to 16383/16/63.

Andries

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Fri Mar 31 2000 - 21:00:18 EST