From: daveh@cbmvax.commodore.com (Dave Haynie)
Newsgroups: comp.sys.amiga.hardware
Subject: Re: New Amiga(s) Expansion/Future
Date: 13 Oct 92 00:44:41 GMT
Reply-To: daveh@cbmvax.commodore.com (Dave Haynie)
Organization: Commodore, West Chester, PA

In article <67346@cup.portal.com> Christopher_Thomas_Winward@cup.portal.com writes:

>   1: The development of the A4000 without a SCSI interface. (Obviously).

>This means that an A4000 is a scaled-down A3000 with the AA chipset.  It
>has a missing interface port, that highly useful SCSI port, that makes the
>A3000 a truly powerful and extensible system.  'But you can buy one as an
>interface board'.  This may be true, but we all know that more devices
>(and useful ones at that) are able to be produced when developers know
>that their target machines will definitely have hardware built in that
>they can support.

I like SCSI myself, and I'll agree that in some cases, built-in hardware
makes a difference to the developer.  But not in the case of SCSI.  Unless
you're the guy writing the device driver, your software better not care
what the underlying disk transfer mechanism is -- SCSI, IDE, ST-506, or 
50,000 monkeys with very good penmanship.  All you care about is "disk", 
"disk capacity", and for a small number of applications, "disk speed".

>   2: The development of the A600 with fully surface-mounted components.

>The A500 is more powerful than this machine because of its sockets and
>expandability.  The missing expansion port is another inconvenience.

Expansion via sockets has always been discouraged and never supported by
Commodore.  Devices that go there tax the machine's power supply and are
often flakey.  The expansion edge might have been kept, but it can't be
kept forever, it's in the way of the memory card map and can't be supported
on non-68000 systems.

>   4: Producing two completely different standards for 'high-end'
>      machines vs. 'low-end'.

>   There is no AA chipset in the A600.  There is no 68030 in the A600.
>   There is no way to upgrade any chips other than the processor in
>   ANY of the new surface mount Amigas other than a motherboard swap.

Which, of course, has nothing to do with surface mount.  If you can hack
in one of these without surface mount, you can hack it in with surface, you
just have to have a technician do it.  The A600 was introduced some 6 months
before the A4000.  They are for two totally different purposes and based on
different architectures.  You shouldn't expect much resembalence between the
two.

>Who in their right mind would ever dare to develop specifically for the
>A4000 and AA chipset when it only comes on one or two of the most
>expensive machines?  

You don't need to.  You develop for the Amiga OS.  If you happen to be on an
AA system, you can use AA features.  This is no big deal to the programmer.
It's not like having to ask for special features or modes, it's simply adapting
to things like different resolutions and bitplane depths.  Good programs have
been doing this kind of things for years, which is why some programs supported
AA features before the A4000 was ever released.  This isn't a C64 we're talking
about here.

>The A3000 was and still is a true innovation in power from C=.  

Gee, thanks.  The A4000 is old news to me, but the A3000 is even older news.
Both are reasonable systems.

>Overall, the A3000 looks like an expandable A4000 to me.

Better get glasses.  You can add SCSI to the A4000 for as little as $75 last I
checked.  Price any AA solutions for the A3000 yet?  Other than that, the A4000
is slightly more expandable than the A3000, in that it has more space inside,
a slightly larger power supply, and a full 24-bit video slot you can't add to
the A3000 no matter how hard you try.

>   1: The MC68060 will probably be 64 bit bus, 128 bit internal CPU.

Maybe, maybe not.  It does standard to reason that folks at C= like me hear 
about the new 680x0 CPUs just a little bit before you do.  I see no problem
with the '060 from what _I_ know of it.

>   2: Zorro IV slots?

>Would it even be useful to come up with a Zorro IV standard for a 64-bit bus
>and if so would it be possible to do that on 100 pins by multiplexing a few
>of them like Zorro III (I realize this requires some assumptions about 68060
>configuration).  Put another way, is it possible to have Zorro II/III/IV-
>compatible expansion slots?

There's no need at present for "Zorro IV".  If you can find 32 more data pins
on the 100 pin connector, even via multiplexing, let me know (MUXing pins that
are needed at the same time doesn't count, we already have burst support for
up to 64 longwords at a time).

>   3: Why not include chipset-expansion cards?

>Would it be so much more expensive, 

Depends on the card.  It's not an easy problem for a large number of things, but
it may happen some day.  With RTG, you can use a Zorro card, but that adds some
cost.

-- 
Dave Haynie Commodore-Amiga (Cool Advanced High-End Systems You Can't See Yet)
 "The Crew That Never Rests"  {uunet|pyramid|rutgers}!cbmvax!daveh   BIX: hazy
              "I got a pocket full of kryptonite" -Spin Doctors