Subject: Re: Utility chip sio's on 4xx (more stories)
To: Herb Peyerl <>
From: mike smith <>
List: port-hp300
Date: 03/22/1997 00:12:53
Herb Peyerl wrote:
> Michael Smith <>  wrote:
>  > On a 16-bit ISA slot there are about 10 IRQ lines.  If I were
>  > implementing the ISA slot on the 425, I'd wire them all together and
> How do we think this works on my 433s? ie: I have 3 EISA slots. Do we think
> "different utility chip"?

Ah, I was not aware that the 433 was an EISA system.  No, that would 
make sense, if one were to assume that on the 433 you had to pick one
interrupt for each slot from each set, or there was a single per-slot

I would have to assume that the EISA bus interface is going to be
at least slightly different from the ISA interface in the 425 

If you have a chance, boot your 433 into the Apollo monitor and tell
us what 

> D 41C000 41C0ff

gives; hopefully it will look like the utility chip is there.  I'm
just booting my first frodo-aware kernel, let's see how it goes...
Nope, I busted it.  Drat.  Ah well, keep trying.

Mike Smith  *BSD hack  Unix hardware collector
The question "why are the fundamental laws of nature mathematical"
invites the trivial response "because we define as fundamental those
laws which are mathematical".  Paul Davies, _The_Mind_of_God_