Path: utzoo!mnetor!uunet!lll-winken!lll-lcc!ames!mailrus!tut.cis.ohio-state.edu!uwmcsd1!leah!itsgw!batcomputer!cornell!uw-beaver!tektronix!tekcrl!tekfdi!videovax!stever
From: stever@videovax.Tek.COM (Steven E. Rice, P.E.)
Newsgroups: comp.sys.amiga
Subject: Re: 68030 Questions
Message-ID: <4890@videovax.Tek.COM>
Date: 11 Mar 88 05:42:47 GMT
References: <4853@videovax.Tek.COM> <3394@cbmvax.UUCP>
Reply-To: stever@videovax.Tek.COM (Steven E. Rice, P.E.)
Organization: Tektronix Television Systems, Beaverton, Oregon
Lines: 23

Dave Haynie's (daveh@cbmvax) most recent article was number
<3394@cbmvax.UUCP>.  In it, he cast aspersions on the poor, struggling
LANCE and suggested that real systems do 32-bit DMA.  Well, maybe --
but if you want to use Ethernet, the LANCE is about the only way to
go, slow or no!

In a perfect world, 32-bit DMA with a 512-byte assembly buffer and 
fast-as-a-speeding-bullet burst transfers would be possible.  In real
life, we have to make do with what we can buy.  (Commodore can build
what it needs; the economics in the Television Test and Measurement
market are different than those in the personal computer market.)

There is another thought, too -- if you have only one DMA device, you
could argue that it shouldn't make much difference if it DMAs into
system RAM or into a dual-ported buffer.  If you have more than one
device contending for the system bus, however, multiple dual-ported
buffers are a clear win.

					Steve Rice

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