From: andrey@cco.caltech.edu (Andre T. Yew)
Newsgroups: comp.sys.amiga.advocacy
Subject: Re: Future Amiga chipset
Date: 18 Dec 1992 08:19:40 GMT
Organization: California Institute of Technology, Pasadena
NNTP-Posting-Host: punisher.caltech.edu

barrett@iastate.edu (Marc N. Barrett) writes:

>In article <n11f4t@ofa123.fidonet.org> Aric.Caley@ofa123.fidonet.org writes:

>> The Amiga came out in 1985, and we got Zorro III in
>>1990,  only a 5 year wait, for a bus standard that is supperior to anything
>>else.

>   Hardly.  The Zorro III bus is simple and sweet.  It works with the Moto
>68000 series, and only with the Moto 68000 series.  It has few facilities to
>take advantage of advanced 64-bit RISC processors, for example, as 
>MicroChannel does.  It gets the job done on '030 and '040 Amigas, and does
>this job very well.  But it cannot compete with MicroChannel as an advanced
>generalized system bus.

	Marc, did you forget to take your medication this morning?
I'm sure you've read Dave Haynie's many posts here about Zorro III
and the technical summary in the Hardware Reference Manual -- Zorro
III is hardly designed to work "only with the Moto 68000 series."
Let's quote the summary without permission here:

"[The Zorro III bus] is not modeled after any particular CPU
specific bus protocol, but instead it's a logical outgrowth of
both the need to support Zorro II cards on the same bus and the
need to achieve various modern feature and performance goals."

	These goals are:

"Compatibility with Zorro II.
 Full 32-bit address path for new devices.
 Full 32-bit data path for new devices.
 Bus speed independent of host system CPU speed.
 High speed bus block transfer mode.
 Bus locking for multiprocessor support.
 Cache disable for simple cache support.
 Fair arbitration for all bus masters.
 Cycle-by-cycle bus arbitration mode.
 High speed interrupt mode."

	Now you're telling us that this is intended only for support
of Motorola 68K family chips?   Why do you want 64-bit support?
What 64-bit MCA cards are out there?  Let me ask you a question:
how many commercial 64-bit processors are there?  Answer: 1.  The
DEC Alpha, which at this point is extremely impractical for any kind
of personal computer (can you say FCC Class B clearance for a 200 MHz
clock, 35-Watt power dissipation, and heinously expensive support
logic and PCB?).   How about this one:  how many 64-bit computers are
out there today?  Answer: none outside of supercomputers, some
mainframes and DEC's workstations (I'm not counting very wide local
bused things like IBM RS/6000's).  What's my point?  By the time 64-bit
processors come down to our level, we'll have a Zorro IV or V to deal
with it because Zorro III will be obsolete by then.

	As for IBM MicroChannel being the great, "advanced generalized
bus", try asking some IBM engineers about a project named Nimble
sometime -- you'll get a very different story, in particular, it's
not even close to what you're saying it is.

>> Memory protection is much harder to add
>>than  you  think. 

>   It's also hard to add multitasking to an OS that was originally written 
>without it.  but that never, ever stopped Amigoids from jumping on MS-DOS and 
>Mac systems for not having good multitasking capabilities.

	It's a design tradeoff -- many things would be sacrificed by
adding memory protection to the Amiga OS.  Speed, nice tools
like Enforcer and Mungwall, and nice IPC, not to mention lost
developement time on DIG, networking, etc.  You should know
this by now.

	Marc, you seem to be reacting by knee-jerk in many of your
rebuttals.  You read a little, draw from a limited knowledge,
and make leaping conclusions that favor your biases.  For example,
a while back you claimed something was vaporware because you
couldn't get it in Iowa, and in this article, you're pitting
the yet non-existent Philips and Motorola hardware against a
working piece of hardware.  What's this called ... hypocrisy?
Incidentally have you ever seen the DMI Editmaster?  I have, and
it works very well in my view.  Besides what studies in human
perception have you done that says JPEG can't be used well for
animation?

	Why don't you consider what you're writing in the future
before posting it?  It would save what little is left of your
credibility.

--Andre

-- 
             Andre Yew andrey@cco.caltech.edu (131.215.139.2)
Newsgroups: comp.sys.amiga.advocacy,comp.sys.amiga.games,rec.games.chess