Re: [9fans] WD hard disk not available in partdisk

[John DeGood <nu3e@yahoo.com>]

Based on reading the ATA-1 and ATA-2 specs
(http://www.t13.org/project/d0791r4c.pdf and
http://www.t13.org/project/d0948r4c.pdf) I agree that the if statement clauses
in sdata.c appear to be reversed.

FWIW, the ATA-6 draft (http://www.t13.org/project/d1410r3a.pdf) declares:
----
   8.15.26 Word 53: Field validity

   Bit 0 of word 53 is obsolete.
...
   8.15.27 Word (58:54): Obsolete
----
Does this suggest that this code in sdata.c may cause problems in the future if
it continues to always assume that the content of bit 0 of word 53 is valid?

> I've tested this on a WD AC2120 (125MB, my disc is smaller than your disc).

I'd try my ST225 (21.4 MB), but I don't think its controller is supported. :-)

John

--- jmk@plan9.bell-labs.com wrote:
> A dumb bug, I fear, introduced between the 2nd and 3rd Edition, but I'd like
> confirmation from another party. I believe the code around line 590 of
> sdata.c
> has the 'current' and 'logical' sectors swapped and should be
> 
> 		if(drive->info[Ivalid] & 0x0001){
> 			drive->c = drive->info[Iccyl];
> 			drive->h = drive->info[Ichead];
> 			drive->s = drive->info[Icsec];
> 		}
> 		else{
> 			drive->c = drive->info[Ilcyl];
> 			drive->h = drive->info[Ilhead];
> 			drive->s = drive->info[Ilsec];
> 		}
> 
> Your old drive does not have LBA mode so this assignment becomes important.
> What puzzles me is that this hasn't caused problems before, as it can lead to
> division by zero later on. This applies to both the kernel and 9load.
> 
> In the later ATA/ATAPI 'standards' all this was finessed away by stating that
> all drives will support LBA mode.
> 
> I've tested this on a WD AC2120 (125MB, my disc is smaller than your disc).
> 
> --jim
> 
> 
> On Thu Jul  4 16:46:16 EDT 2002, nu3e@arrl.net wrote:
> > I tried to install 4th Edition on an old Western Digital AC2340 340 MB hard
> > drive.  The hard drive is recognized by the BIOS and works with DOS and
> > Win95, but it does not appear in "partdisk" during the Plan 9 install.  I
> > also tried an old Seagate ST3243A 214 MB hard drive and "partdisk"
> > recognizes it fine.  I tried all master/slave combinations of the AC2340
> and
> > ST3243A, and in every case only the ST3243A is available in "partdisk".
> > 
> > Here are snippets of what I get with the ST3243A as primary master and the
> > AC2340 as primary slave.  In every case the AC2340 appears to be recognized
> > early in the boot process, but it is never available in "partdisk":
> > ----
> >   dev A0 port 1F0 config 045A capabilities 0000 mwdma 0000 dma 00000000 rwm
> > 8
> >   dev B0 port 1F0 config 427A capabilities 0100 mwdma 0000 dma 00000000 rwm
> > 16
> >   dev A0 port 170 config 8580 capabilities 0B00 mwdma 0003 dma 00000000 rwm
> > 0
> > ----
> >   The following disk devices were found.
> > 
> >   sdC0 - ST3243A
> >   * p1     0     1023  (1023 cylinders, 203.80 MB) FATHUGE
> >    empty  1023  1024  (1 cylinders, 204.00 KB)
> > 
> >   sdD0 - NEC CD-ROM DRIVE: 2523.18
> > ----
> > This system has an old Intel Plato (aka Premier/PCI II) motherboard
> (Pentium
> > 90 w/ 430NX chipset).
> > 
> > I also tried a 3rd Edition 9disk.9fd and had the same problem.
> > 
> > Am I doing something dumb or is this a bug/feature? :-)
> > 
> > John
> 
> 
> 


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