Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!unmvax!gatech!udel!mmdf
From: gay%elde.epfl.ch@cunyvm.cuny.edu (David Gay)
Newsgroups: comp.sys.amiga
Subject: Re: video/hard disk problems
Message-ID: <11366@louie.udel.EDU>
Date: 22 Mar 89 13:49:55 GMT
Sender: mmdf@udel.EDU
Lines: 34

In article <798@zehntel.UUCP> donw@zehntel (Don White) writes:
>
>From donw Wed Mar 15 10:56:36 1989
>To: zehntel!sun!sugar.hackercorp.com!karl
>Subject: Re: Drive Performance Degredation
>
>
>    This is NOT an Amiga problem. This is a 2090A problem. If you use a
> different drive controller the problem goes away. Commodore admitted (hearsay)

> that when the 2090A was designed, whoever did it didn't think that loading
> pictures would be to large a part of the users activity, so they used the
> same DMA channels which display an image to transfer it.

Seeing that the display is already using all the cycles that are available to
access chip memory, it's a bit difficult to avoid it ... Haven't you noticed
the slowdown with such a display present ? The only time anything can access
the chip memory, with a HIRES 16 colour screen, is during horizontal and
vertical retrace.

> My understanding is that they don't intend to fix it. They intend to make
> the multiplexing more efficient. (i.e. kludge)

I'm not sure what else they could do ? (or have you got a magic wand ?)

>     Don White
>     zehtnel!donw

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David Gay                                  6 x 9 = 42

GAY@ELDE.EPFL.CH, or GAY%ELDE.EPFL.CH@CLSEPF51.bitnet

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