Date: Sat, 8 Jul 1995 16:09:52 +1000 From: Bruce Evans <bde@zeta.org.au> To: terry@cs.weber.edu, wilko@yedi.iaf.nl Cc: davidg@root.com, freebsd-hackers@freebsd.org Subject: Re: Stabikity/Usability of 2.0.5R Message-ID: <199507080609.QAA17575@godzilla.zeta.org.au>
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>In the translate mode, the spare sectors will not be accesible by the
>host (!!! WKB) and will require the firmware top check the requested cyl, head
>and sector values before doing the translation.
>Translated mode is invoked by issuing a set params (91hex) at 17 or 34,
>which is performed by the DOS Bios (??? WKB) at boot time. This option
>may be disabled if jumper W14 is installed. W8 if jumped and W14 open
>enables WD1005-WAH compat mode, which employs only the double translation (
>1 phys track is 2 log tracks). Other operating systems may like to utilise
>the ESDI drives in a pure physical manner"
The driver now assumes that
(0) the default geometry advertised by the driver can be set using set
params.
Previously it assumed that either
(1) the apparent geometry can be varied using set params.
All reasonable geometries work.
The user-specifed geometries in the partition table and in the
disklabel are reasonable.
or
(2) The apparent geometry isn't affected by set params.
The user-specifed geometries in the partition table and in the
disklabel agree with the fixed geometry.
Apparently, ESDI drives often advertise a geometry that isn't quite
right (having 1 spare sector that can't be accessed). This shouldn't
be much of a problem if translation is enabled - the advertised
geometry will just have too many cylinders. If translation isn't
enabled, then the driver will no longer work. It used to work if
the user-specified geometries were as in (2) - e.g., 34 sectors
instead of 35.
>It appears to me that the card reports 35 sectors/tr of which 34
>are data and 1 is inacessible (see (!!! WKB)). This might explain why
>n * 35 is a show stopper. Also, this seems to correlate with me
>using 34 sect/tr on 115R.
>I just tried installing W8 and removing W14. Now the 205R probe sees
>36 sect/tr.
If you had 14 installed before then it's hard to explain why translation
didn't work. Perhaps set params to the advertised geometry doesn't work,
although translation is required to go from 35 advertised sectors to 34
usable.
Bruce
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