Subject: Re: more on the 400-series utility chip
To: Jason Thorpe <thorpej@nas.nasa.gov>
From: mike smith <miff@spam.frisbee.net.au>
List: port-hp300
Date: 03/21/1997 19:49:01
Jason Thorpe wrote:
>
> We have the following items (offsets from util chip base)
...
> 0x0080 calendar of some sort
This one's a bit weird; have to keep looking at it.
> 0x00d0 diagnostic control register
Interesting!
> 0x00e0 isa pic
...
> Now, bits in the isa interrupt status register (appears to be a single byte):
>
> 0x01 off if service switch is set to "service"
> 0x02 on if interrupt on isa IRQ 3, 4, 5, or 6
> 0x04 on if interrupt on isa IRQ 7, 9, 10, or 11
> 0x08 on if interrupt on isa IRQ 12, 14, or 15
Hmm I wonder if that goes along with the information I already have on
the
'isa pic' register, ie. the lower bits in the pic register would mask
the
ISA interrupts, and the higher bits in the status register correspond to
the apci ports?
> I have some more random notes about where ISA lives and how the i/o
> space is encoded... I'll hunt for them.
Magic! Thanks!
> Jason R. Thorpe thorpej@nas.nasa.gov
--
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_