On Wed, Jun 09, 1999 at 07:57:19PM -0700, Jonathan Stone wrote:
> 
> I have an ~4-year-old machine with a Triton II chipset set up ina lab
> rack. I find I need to hang about 80 gigs of disk off it.  Can I
> remove the CD and stick two ~40-gig (currently UDMA) drives on this
> machine, one on each channel, or with the UDMA drives not work on this
> old chipset? Does it matter that the high-density drives are rated for
> UDMA / 66, or (like scsi) will newer drives work with older
> controllers?  Or will I run into stupid c/h/s limits?

From what I see this is a PIIX controller. This should work in DMA mode 2,
but you need to be carefull if you put a slave device one controller:
the PIIX can't use different timings for master and slave; it will use the
lower one.
There's no c/h/s problems with NetBSD (it can use LBA), and if you only
install NetBSD on this disk, just put the root part below 512Mb, so that
you can put the usual failsafe 1024/16/63 geometry in the BIOS to boot.

About hardware backward compatibility: it *should* work, but you're never
sure with IDE, it's so sensible to cables and devices characteristics ...
in DMA mode 2 you could encounter data corruption problems if things go
bad (UDMA has a CRC transfert error detection, and it's sometimes usefull :)
It will always work if you force it to PIO mode 4, though. This can give you
some extra time to get a UDMA-capable motherboard.

> 
> Sorry to ask such a dumb question, but till now I've used SCSI
> precisely to avoid this stuff. But the price difference is big.

Sure, but "you get what you paid for". For a server I will never use an
IDE disk. These are reserved to workstations and routers (other's
workstations, mine is SCSI :)

--
Manuel Bouyer, LIP6, Universite Paris VI.           Manuel.Bouyer@lip6.fr
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