Subject: Re: Multiple busses of the same kind
To: Nathan J. Williams <nathanw@MIT.EDU>
From: Bill Studenmund <>
List: tech-kern
Date: 07/30/2001 12:16:37
On 30 Jul 2001, Nathan J. Williams wrote:

> Bill Studenmund <> writes:
> > Right, but you can really only have one subtractive-decoding bus in a
> > system. So one of these two isa busses has to be postitive-addressing
> > only.
> To be picky, that's a rule for a single PCI bus tree. There wouldn't
> be anything wrong with having multiple primary PCI buses, each with
> its own independent address space, and each one of those having a
> single subtractive bridge. Mutliple-primary-PCI systems certainly
> exist.

True, but then wouldn't both of these isa busses appear in different parts
of the processor's address space?

Does our isa code deal with isa busses not being at 0-1 MB?

Take care,