From owner-freebsd-small  Tue Jan 18 22:32:22 2000
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From: Mike Nowlin <mike@argos.org>
To: Tim Tsai <tim@futuresouth.com>
Cc: Chip Marshall <chip@eboai.org>,
	freebsd-small <freebsd-small@FreeBSD.ORG>
Subject: Re: PC/104
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>   One additional difference is that PC/104 supports IRQ sharing (across
> different devices on the bus).  I don't remember the details <mumbles
> something about impedance and pull-up/down>

I've been kinda wondering about this for a while....  From everything I've
been able to find, it's not the ISA bus itself that causes problems with
sharing IRQ's, but it's the cheap cards we're so used to seeing everywhere
that don't use open-collector drivers.  I have successfully shared
interrupts using old (bulky, lots of chips, sucks up lots of power) cards
in the past, but the modern stuff hates it.  

Any input?

mike




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