IDE disk problem

[Joel]

> >>Generally, in my experience, intermittent errors can sometimes occur on
> >>a CS cable with the drives jumpered as master/slave. I have never had a
> >>problem with the drives set to CS though.
> > 
> > 
> > I wonder if this might be due to selecting a drive as master but hanging
> > it in the middle. I'm thinking that floating input could cause the
> > controller to miss selects forced against the pattern, and suspicious
> > that manufacturers may not be testing the controllers, cables, and/or
> > drives with slave and master strapped, but master in the middle. 
> 
> Well how do you explain in binary logic the float thing ?

You're gonna love this --

I haven't seen the spec, but one typical way to use float as a state is
to check the pin's state first, then try driving it to the opposite
state and checking the result, and then try driving it again to the
original state and checking again. If the pin is strapped, it will
refuse to go to one state.

IIRC, there are also gates which can detect tri-stated inputs under
specific engineering parameters, as well. I remember looking at the
diagrams and thinking, "Man, some engineer has been drinking too much
coffee."

Anyway, no, it's not binary logic.


--
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> **