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Date: Wed, 22 Mar 1995 16:10:18 +1000
From: Bruce Evans <bde@zeta.org.au>
Message-Id: <199503220610.QAA04588@godzilla.zeta.org.au>
To: davidg@freefall.cdrom.com, rgrimes@gndrsh.aac.dev.com
Subject: Re: cvs commit: src/sys/i386/isa wd.c wdreg.h
Cc: CVS-commiters@freefall.cdrom.com, cvs-sys@freefall.cdrom.com
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>>   Correct delay to use port 0x84, reading the status register
>>   might not be a long enough delay.

>Port 0x84 will not cause the 1.25uS delay on some PCI motherboards,
>I beleive all Intel Neptune and Triton based boards know that this
>is not an ISA address and end up running only a PCI I/O cycle for
>it.

What are the cycle timings for all PC buses?

ISA: 6 min + normally 4 extra = 1.25uS at 8MHz ?
EISA?
PCI?

Bruce