Re: Hard disk problem solved

[Peter Holzer <hp@gipsy.vmars.tuwien.ac.at> writes:]
>Yesterday I managed to coax my hard drive into seeking at maximum
>speed. Here are the patches to wd.c and wd.h. They also limit read and
>write operations to a single track, because my drive obviously had
>trouble with track switching.

>From my reading of your diffs, it looks like your controller won't
automatically advance to the next head. I'm guessing that this is
because you have to use a pseudo-geometry (did the readp or the cmos
command work for you in boot/boot.lst?) and thus the wd driver
isn't able to tell when it would be OK to ask for multiple tracks.
Thus, perhaps I should add a flag so that CMOS geometries will not
use multiple track reads, but readp geometries will (because they're
more likely to be right).

I'm puzzled by why your drive needed a recalibrate. Since we boot
from DOS, it should've been recalibrated already? It's good to add
such initialization, but I'd like to understand how the drive got into
an uncalibrated state in the first place.

Is it necessary that the drive be calibrated twice? I see a recal once
during the scan for disks, and again on the first I/O setup. Is this
needed? There's no place which clears the calibrated[] entry, so why
does this flag (calibrated[unit]) need to be kept?

                                        Regards,
                                        Andy
Received on Thu Sep 9 08:43:56 1993