IDE disk problem

[Joel]

Okay, I spent a little more time at the place that explained UDMA
(pcguide.com) and I answered my own questions:

> [...]
> > Cable select is exactly what it says, and is VERY reliable in my
> > experience.
> 
> I used to repair computers with 5 1/4" floppy drives, and in those days,
> CS was an epithet. Been a while since I've messed with mainstream
> hardware. I'm going to have a lot of bias to get over if CS really is
> reliable these days.
> 
> > -Use a cable select cable
> > -plug the drive to be used as master to the connection designated as
> > master.
> > -plug the drive to be used as slave to the connection designated as
> > slave.
> 
> So, if it's a CS cable, it should say on the connectors something like
> "motherboard", "master", and "slave"? If it doesn't say, I can assume
> the guy at Pasokon Koubou knew I didn't want a CS cable? Or maybe this
> whole business is why he didn't want to recommend using the slave
> channel in a multi-drive, multi-boot setup?

Blue is motherboard.
Gray is slave.
Black is master.

> I guess I'd better take a look when I get home tonight. I don't want the
> drives fighting with the cables on my new cheap Linux/BSD sixOS
> multi-booting toybox.

Pin 28 is grounded for master, floats for slave. If CS is selected on
both drives, the controller checks pin 28, but if one drive is selected
as master and the other as slave, the controller ignores pin 28.

So, other than you want to put the master at the end anyway (to avoid
data reflection on a non-terminated cable if you happen to remove the
slave), as long as you make sure that one is selected master and the
other slave, you're okay. 

Or you can let the cable select them.

That's good to know. 

Thanks, guys, I guess I needed a reason to look that up.

--
Joel Rees   <rees at ddcom.co.jp>
digitcom, inc.   株式会社デジコム
Kobe, Japan   +81-78-672-8800
** <http://www.ddcom.co.jp> **