Subject: Re: Utility chip sio's on 4xx (more stories)
To: None <>
From: Michael Smith <>
List: port-hp300
Date: 03/21/1997 16:42:15
Jason Thorpe stands accused of saying:
> On Fri, 21 Mar 1997 14:57:26 +1030 (CST) 
>  Michael Smith <> wrote:
>> Of course, if it _does_ implement ISA properly (ie. provides both
>> I/O mapped and memory mapped space, as well as busmaster DMA), then there's
>> no end to the evil things that could be done with it.  8)
> ...well, remember, the whole notion of i/o-mapped is sort of tied to the
> old Intel family... there was an additional line that was raised to
> indicate "i/o port" rather than "memory" addresses.

Yeah, although you're leaving a few other bits out there 8)

> In any case, i/o-mapped access is emulated on other CPUs... it's actually
> memory-mapped, typically with a mutant address decoding.

Exactly; sorry if I wasn't clear above - I am quite familiar with the
options as they apply to talking to ISA with memory-mapped processors 8)

All I meant was that I hope that there's both an I/O map window and
a memory-map window (even if it's only the 384K 'hole'); you could argue
a serious life extension for one of these machines with something like an
ISDN card or a multiport serial card, or even just a Soundblaster 8)

>  > I'll go read it before I make more of a fool of myself 8)
> No fools here :-)  bus.h isn't implemented on the hp300 yes, but it really
> ought to be.  That's on my medium-term TODO list, but I may have to bump
> it up if you guys keep making progress :-)

We live to perturb your organisation 8) I know I keep begging, but
_any_ information you have is going to be helpful; right now I could
kill for any details on the interrupt structure of the 4xx that might
help work out where the utility chip interrupts (so I can link the
frodo driver in) and what any of its registers do (so I can demux
interrupts 8).

> Ah ... I was going to suggest hooking up w/ some other NetBSD hackers
> in Melbourne... beer-by-proxy :-)

*grins*  I'll be there over easter, but a hair on the busy side then.

> Jason R. Thorpe                             

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