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From: Michael S <already5chosen@yahoo.com>
Newsgroups: comp.arch
Subject: Re: Architectural implications of locate mode I/O and channels
Date: Wed, 3 Jul 2024 16:00:27 +0300
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On Wed, 03 Jul 2024 08:44:01 -0400
EricP <ThatWouldBeTelling@thevillage.com> wrote:

> 
> An alternative is each device has its own DMA controller
> which is just a couple of counters.
> 

The main cost is not counters, but bus mastering logic.
For PCI it was non-trivial cost even as late as year 2000. For example,
PLX PCI to local bus bridges with bus mastering capability, like PCI
9080 costed non-trivially more than slave-only 9060.