Problems in Modernizing the IIgs, con't

[bjblackbear@ibm.net (B.J. Major)]

Sent:        11/1/97 5:26 AM
Received:    10/31/97 8:14 PM
From:        Lewin A.R.W. Edwards, sysadm@zws.com

>>hoping to choose an example about which I knew nothing in order to
>>perform a little smoke-and-mirrors magic, you've been unlucky.
>
>I'm insulted that you would even think that.  The very reason I

Oh, I am *so* sorry; I stand chastened and rebuked. Since we're getting
so emotional, I may as well add that I believe there is a strong 
possibility that this so-called conversation never took place, and that
it was simply invented to bolster an exceedingly weak flat-earth point
of 
view.

>To say it made no sense to develop the '816 beyond is current
>state is like saying there was no sense to develop the original
>68K into an '040.  The Pentium was derived from an 8080, so it

Compare units sold. Where was the 65C816 used on a commercial scale?
Only 
two places that I know of, and both of them were places that used the 
65C816 PURELY to leverage a large existing 6502 code base. (Nintendo 
chose it for the Super Famicom because NES devtools and developers were
trained around the 6502 used in the Famicom, and Apple chose it because
of the large number of 6502 developers). To my knowledge, only one 
company ever manufactured the 65C816.

The 8080 was second-sourced from National Semiconductor and also SGS, I
believe. It was used in a FRIGHTENINGLY large number of CP/M machines, 
single-board computers and other applications - orders of magnitude more
than the 65C816 (and the Z-80, which is a cunning 8080 knock-off and 
enhancement, was even more popular). The 8080 "earned" its future 
development path from unit sales.

At the time Apple chose the 6502, it was an incredibly popular MPU used
in many general-purpose and embedded applications. So the 6502 was a
wise 
choice. The 65C816 was a *bad* choice. Nobody else was using it. Apple 
would have had to finance any future development of that semi range 
entirely on their own. Dumb. Much smarter to choose a popular MPU which
other people were using, high volumes used by others bringing price down
for Apple.

>could be done.  There are many factors in a CPU chip besides the
>data bus.  The 65C816 already has 24-bit addressing and in this

The 68K had linear addressing, upwardly 32-bit compatible and a vastly 
superior instruction set.

>feasable!  The GS outsold the entire Mac line during its first
>year.  The only reason sales dropped later was that Apple
>deliberately cut advertising and marketing.

Whatever you say, the 65C816 is essentially an 8-bit MPU with 16-bit 
extensions, and by the late 1980s the entire world had moved to native 
16-bit CPUs. As I said before, and you conveniently ignored, the
question 
is one of what everyone else in the world is doing, and keeping in step
with current technology trends.

Face it, the Apple II pre-GS was very successful, and Apple wanted to 
continue the success, but the GS was a false start along that trail.

>It would have been SMART for Apple to continue developing the
>65xxx series.  They already had a "full house" of customer base.
>Most of us deserted Apple after it deserted us.  Look at what
>bad shape Apple is in today.

Oh, rot - pure and simple. There is what can only be described as a 
lunatic fringe of rabid Apple-haters living on usenet, who feel betrayed
and abandoned because Apple discontinued the II line. I'm sure there is
a 
similar lunatic fringe that mourns the fact that DEC has discontinued
the 
PDP-11 line, and argues bitterly that the LSI-11 is the MPU for the 
future.

>>The Mac 512K and upwards have a vertical retrace interrupt service
which
>>could similarly be used to implement a fully preemptively multitasking
>>OS, if someone could be bothered.
>
>Then why did "someone" never implement preemtive multitasking in
>MacOS?

Why bother? Apple never did it because presumably nobody important
enough 
ever asked for it. It wasn't until the mid-1990s that people have
started 
to regard it as an important feature- though even now, 9/10 of computer
users still use their machines modally and wouldn't notice the
difference 
between Windows 3.1 and Windows 95 as far as multitasking goes. The most
complicated operation most people ever undertake is to print a document
while working on the next draft.

>As for the Amiga, be reasonable.  We're comparing the A500 to an
>68000 Mac.  The Amiga actually did evolve to use later 68K
>derivatives and these later models of the Amiga had an MMU.

The vast bulk of Amigas shipped were the A500, A600, A1200 and CD32,
none 
of which had an MMU as standard, and on NONE of which could you fit an 
MMU without an expensive third-party CPU upgrade.

>>In artificial tests of non-real-programming-task instruction mixes
only.
>
>BS!  An GS accelerated to 7MHz will beat out a 7MHz black and

BS yourself. You haven't measured it. I'm not talking a loop to see
which 
MPU can execute more NOPs per second, I'm talking about real functional
benchmarks. As I said earlier, you are letting your personal hatred of 
the 68k and Macintosh and basically everything other than the Apple II 
blind you to simple facts.

>>>chips, which is why our graphics are so much better than the
>>>equivalent Macs and don't slow down the computer."
>>
>>That indicates a serious lack of understanding of the Amiga's
>>architecture, too. The baseline A500 does not outperform any color
>>Macintosh in terms of graphic performance because "the custom chips
>>don't slow down the computer".
>
>So the chips and the 68000 fight for time.  So what?  The end
>result is that the custom graphics coprocessor moves graphics
>faster than the 68000 ever could.  The 68000 could go to sleep
>for all the user cares, as long as the job gets done faster.
>That's why an A500 outperforms any 68000 Mac in graphics.

There is a hell of a lot more to a computing session than putting a few
sprites onscreen.

>There were no color 68000 Macs.  The 68000 A500 beats out any
>68000 Mac in graphics and it does so in color (more data moved)
>while the Mac does so in 1-bit b&w (which should give it the

Okay then, let's compare the A500 with 1Mb RAM to the Atari 1040STe 
(blitterless), which is a very close comparison because the technical 
specifications are almost identical, except that the Amiga has 
coprocessors and the STe doesn't. The STe's graphics performance is
quite 
close to the A500's for most operations. Put them side by side and you 
would be hard put to tell the difference between an ST game and an Amiga
game.

>>The reason that the blitter in Agnus
>>makes animation tasks smoother and faster on the Amiga is because this
>>device is essentially a custom MPU optimized for graphics operations.
>
>Great, isn't that the point?

No, the point was your so-called quote above which said that this
"didn't 
slow down the computer". Are you a programmer? You certainly don't argue
in a very linear or logical sort of way.

>>Buss contention slows the 68000 to a crawl when you're using
>>high-resolution graphics on the stock Amiga 500. Audio, disk and
blitter
>>DMA slow it down even more.
>
>SO WHAT?  The 68K could go to sleep for all the user cares,
>as long as the rest of the computer can get things done faster!

Oh, wonderful. Let's see you calculate your spreadsheet with sprites.

>CPU and a 20MHz motherboard.  Here's what he said:

I read what he said, and there's no need to requote all this stuff; 
saying it again won't make it so, and this:

>Based on my conversation with him, I'd say Apple would have
>had a winner using the following timetable:

is still a commercial fantasy. Face it, big companies beat small ones, 
big selling products beat small selling products, and the 68k and
PowerPC 
are big selling products made by a big company.

>You did not quote the full text above.  The point made was that
>there is a market for an appliance computer.  Think about this:

It's a very limited market, and the actual assigned cost of manufacture
of an embedded WP system retailing for $400 would be no more than 
$150-200 at MOST. The cost of a monitor alone is slightly more than half
that.

>have computers.  The Macintosh has failed as "the computer for
>the rest of us."

If that is true, then there *is* no "computer for the rest of us", 
because there sure as hell isn't anything else which comes close to 
filling that niche. Don't tell me that the Apple II series as shipped is
easy to set up (for a *novice* user), because I might rupture something
laughing. User interface paradigms have come a long way. Sure, you could
upgrade GS/OS, but again we're talking added cost, and why *bother* when
there are off-the-shelf products like MacOS which fulfil the
requirements?

>the PC.  Similarly, capable PC systems under $K no longer exist.

Really? You might be tickled to learn that the retail price of a 133MHz
6x86-based PC with 14" SVGA color monitor, mouse, 16Mb RAM, minitower 
case, 12x CD-ROM, 1.7Gb hard disk, 104-key keyboard and 3.5" FDD is
about 
AUD$1200-AUD$1300 here if you shop for cheap clones. That's 
USD$840-USD$910. I read in Be developer news just a few weeks ago an 
aside about buying a Pentium PC for a little under USD$600.

>circuits can be designed as such.  Without the power drain of
>something like an Intel or 68K chip in there, the device could

You actually have energy consumption figures for the low-power version
of 
the MC68000?



=== From the Apple PowerBook of ======================
Lewin A.R.W. Edwards [Team OS/2] <http://www.zws.com/>
Programmer + Hardware Eng     Certified Apple Engineer
Need a programmer?    <http://www.zws.com/resume.html>
Tel  +61-412809805                   Fax +61-392281335
"No non-trivial programming task is atomic" - LARWE 97
=== (C) Copyright 1997 by Lewin A.R.W. Edwards =======