From: gblock@csd4.csd.uwm.edu (Gregory R Block)
Newsgroups: comp.sys.amiga.advocacy
Subject: Re: Zorro III Stuff (Was: Guesses, et al.)
Date: 7 Apr 92 15:35:22 GMT
Article-I.D.: uwm.1992Apr7.153522.24539
Organization: University of Wisconsin - Milwaukee

daveh@cbmvax.commodore.com (Dave Haynie) writes:
[comparisons of expansion architecture deleted]
: Now, one thing about Zorro III is that it can always improve with clock
: speed, at least within the limits of what we can build in CMOS.  Zorro III
: doesn't use a bus clock, it uses asynchronous strobes to govern the 
: relationships between master and slave signals.  This has the advantage of
: making it clock speed independent.  The actual theoretical maximum speeds

Where are the strobes picked up from?  I take it they're produced in
whatever the 3000 uses as a Gary (I can't remember the name, sorry.
;) based on the speed of the processor's clock?

: on Zorro III are probably faster than you can likely get out of real TTL
: levels; some 150MB/s using burst.  But the faster the clock you have to work
: with, the closer to theoretical the bus can get, both in the relationship
: between strobes and the synchronization delay you'll generally get at the
: end of a bus cycle.  The A3000 implementation, at a reachable 20MB/s without
: burst, represents the low end in Zorro III -- it's very realistic to expect
: better in future machines.  Not that Zorro III will solve all problems; you

So the 3000 is "hardwired", to use a word, to its current "strobe
patterns"? (trying incredibly hard to NOT use buzzwords...)

: don't expect one bus to necessarily solve both I/O and multiprocessor 
: interconnect questions, for example.  Consider also that we are talking about
: personal systems here; bus speed tends to be one of the first things to go
: in a PClone when you're taking about price wars, and Apple's never given all
: that much consideration to it either.  Based on the success of the A2000's

It seems they're slowly changing their mind, however.  ;)  Was
ZorroIII a completely made-up design, or was it based around some
other bus?

: expansion features, the reality that C='s not going to crank out a new
: motherboard with one slightly new feature every three months, and my personal
: philosophy which balks at such throw-away systems anyway, we found it importa
: to give the expansion bus such consideration.

Sounds like a viable reason.  ;)  However, sometimes, in order to get
reasonable performance on an upgrade, a motherboard swap can be near
necessary.  An 040 on a 3000, for instance, is far less a problem than
the bottlenecks created by an 040 on a 2000...

: The bus is always a bottleneck in some situations, but far less for intellige
: boards.  The "Draw a Circle" command for a dumb frame buffer results in all 
: kinds of bus transactions between the host processor and display memory, as t
: host processor draws a circle.  The same command ideally results in the 
: "Draw a Circle" command being sent to the graphics processor on an intelligen
: board.  At best, the bus starts acting more like a high speed network than a
: memory interface.  This is firmly coupled multiprocessing, exactly what you
: would like to have in an Amiga.

Exactly what I'd like to have.  ;)  Unfortunately, this is based both
on hardware and software of the computer in question, and, though the
hardware is great, the software's support for such things is
lackluster at best.  I hope that the TIGA support coming in the way of
software makes use of what is possible in such situations.

: Actually, the A2410 can.  But, based on the memory determinism requirements
: of the 34010, it's not safe to have it bang on Chip RAM or any other memory
: that could lock the 34010 out for some time.  I'm no expert on either of thes
: processors, but I gather that the 34020 is much easier to deal with.

Under the 3000, would it matter if the 2410 is banging on chip ram?
Could the A2410 get locked out from chip on that design?  I know it
can happen on the 2000, but I'm not up enough on the 3000...  I
wasn't sure if the custom chips could still lock out cpu access to chip.

: I don't think requiring the GUI to use more colors makes any sense at all.

Definitely not.

: Allowing it more colors per se is still going to pay a pretty high price for
: something that's not useful.  Even if you had a fast 24-bit display, do you
: really want to pay any additional processing or memory penalty so can, say,
: have 24-bit icons?  Sure, it would look cool, but most folks have better
: things to do than design 24-bit icons anyway.  256 color icons are overkill.

I think 16 color icons are overkill.  ;)  But if a 24-bit display is
so fast that one would want to use it for the GUI, it would be wiser
to use an EXTREMELY fast lower-bit display, and save CPU for the applications.

: On the other hand, a GUI that can effectively manage a deep display without
: incuring the overhead itself would be a wonder -- if you need 24-bit color,
: supporting it optionally without necessarily having to switch mode all the
: time would be fantastic.

But a GUI managing a deep display and itself using 24-bits are two
different things, aren't they?  One could "set" the workbench to
24-bits, but the GUI doesn't really have to have an "understanding",
just a few extra precautions... unless I'm overlooking something.  And
I've got that nagging feeling...

: Well, I'll take BLAZEMONGER over Emacs as my GUI any day of the week.

BLAZEmacs will be out 3rd quarter of 2000, about the expected time of
the next chipset from C=.  ;)  (Sorry, had to do that MB thing just
once.  :)

: Hey, that's what we all need to get these kids off their video games and onto
: real fun.  Rather than clicking on the icon, you have to shoot it.  Rather th
: pulling down a menu, you have to wrestle with it.  You can't move a window 
: around until you beat it in a sword fight.  I love the idea!

TSR will probably sue you for it.  ;)  The first ever "Active User
Interface".  Jack Lelaine and Cher will come out with interactive
workout videos using the AUI, pronounced "owwie!", to firm, tone, and
limber up that sword arm and trigger finger, and personal trainers
will flock to the computer industry to help you with your wrestling
form, your fighting style, etc...  Soon, the world will become a
caste-based warrior society, when working at home is more than just a
job, it's a life-threatening experience.

Bungee jumping and skydiving will go out of style, to say the least.  ;)

: I think you'd complain loudly if you didn't have any Fast RAM...

I'd be crying far to hard to complain.  ;)  If only it didn't eat EVERYTHING.

Greg
-- 
 __________________________________________________________________________
|				     The Chesterfield Electronic Towel (TM)|
|gblock@csd4.csd.uwm.edu                    Don't leave Krikkit without it!|
|__________________________________________________________________________|
Newsgroups: comp.sys.amiga.advocacy