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To: Tony Overfield <tony@dell.com>
cc: Mike Smith <mike@smith.net.au>, hackers@FreeBSD.ORG
Subject: Re: INB question 
In-reply-to: Your message of "Sun, 28 Sep 1997 02:00:01 EST."
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Date: Sun, 28 Sep 1997 18:50:03 +0930
From: Mike Smith <mike@smith.net.au>
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> >Read it again.  1.3MegaWords.  Specifically, implying that it's making 
> >1.3 million 16-bit I/O transactions per second, or 2.6MB/sec.
> >
> >Yes, this is substantially faster than I was expecting.  8)
> 
> 16-bit ISA I/O cycles are not only wider but also faster than 8-bit ISA 
> I/O cycles.  Back when IDE drives were still attached to the ISA bus, a 
> fast drive could transfer about 3.5MB/sec, but 2.5MB/sec or 2MB/sec was 
> more typical.  The speed depends on the chipset and the way that the 
> BIOS programs the ISA timing options.

Gotcha.  Hmm, does this mean that you can read an 8-bit peripheral 
faster by using 16-bit cycles, or will the sizing signals trip you up?

mike