6809 vs. '286 (long - Was: Re: Still OT: Pentium / M$

From: Roger Merchberger <zmerch_at_30below.com>
Date: Fri Jan 1 23:16:13 1999

On or about 10:53 PM 12/29/98 -0500, Allison J Parent was caught in a dark
alley speaking these words:

><The lowly Motorola 6809 at 2 Mhz outperforms a
><10Mhz 80286... by far. It also *smokes* the 6502. And other than Xenix 286
><(super-expensive), OS-9 is the most powerful OS available for these
><processors, and at a reasonable cost (When I bought my copy - $139.)...
>
>the 6809 was pretty neat and close to PDP-11.

If that's true, I'd really like a PDP-11! ;-)

> It was however, slow!

Compared to what? Clock per clock, it was the fastest thing for quite a
long time. And remember, the 6809 was *not* the fastest of the fast
8-bitters... ever heard of a *6309*??? Pretty rare critter there! Made by
Hitachi as an OEM to Motorola, CMOS, 3MHz (most overclockable to 4MHz) and
would kick a '286 in the backside easier than anything 8-bit (with 6309
hand-optimized code) -- it did have twice the registers of the 6809 and had
-- no typo here -- 32 bit math capabilities.

>Comparing it to a 286/10mhz, sorry, no way.

I did it. Admittedly, it wasn't *purely* apples to apples comparison, but I
took totally portable M$Basic programs doing integer & real math, and
integer, real & string sorting, and ran them in RS-DOS on a CoCo2 and in
Basic & BasicA on a True-Blue Bummer/AT '286-10. At .89 Mhz, the 6809 was
roughly .7x in everything except integer-related items - remember, RS-DOS
doesn't have integers... everything's a five-byte real.

Tweak the CoCo2 to 1.78 Mhz (mine ran stable at that speed), and the CoCo
bettered the AT by just under 10%. Just for shits&grins, I *really*
optimized the code for Basic09 and booted OS-9. Even at .89MHz, the CoCo
won, by a decent margin... but this part is moot; just included for
hystericals.

Oh, and both proggies had *minimal* output - video was faster on my CoCo,
you know - didn't want to take undue advantage of that IBM. ;-)

> The 286 wasn't great but it was faster.

How, tho. compiled C to compiled C? Sure. But how about optimized assembly
vs. optimized assembly? IIRC, most (if not all) instructions execute in
fewer clock cycles on the 6809. But also, the addressing capabilities of
the 6809 far outweigh anything 86ish - I've tried learning x86 assembly - I
ran screaming into the night... took my wife a week to find me! Any assy.
job I've ever seen can be done in a *lot* fewer instructions on a 6809 than
an x86.

In my book, faster _and_ fewer gives a pretty decent improvement - sure, a
couple loops would run faster on a '286, but a regular proggie is more than
just counting loops, and all of the branching & indexing capabilities of
the 6809 really improve the odds.

>Like you said marketing... who outside of us remembers OS-9 and the 6809?
>Was the coco a better machine... no. It was good for it's time but the
>system was still a grafted together set of pods and cables typical of many
>of the trs-xx products.

As were most _inexpensive home machines_ of the time. I have a "podified"
Atari 800 (2 disk drives, small printer, etc.), I've seen many "podified"
Commie 64's & such... I really don't think the business machines from
RS/Tandy were any more "grafted" than the IBM tho.

The IBM was *not* slated as a home machine. It was a business machine, and
I will agree totally that pods and wires (at the time) would never be seen
as a businesslike machine.... but today... (I have more cables coming from
my Pentium then I *ever* had out of my CoCo3 - and yet it seems only
*marginally* more useful.)

IMHO, a <$1000 loaded home machine is *not* supposed to outperform a >$4000
business machine. Oh, and Ward could prolly answer this: Was there a
version of Xenix available for an IBM / Clone? I know there was one for
the Tandy 2000, but that's the only version I've ever seen. How far did
M$'s licensing go with that OS?

In closing, anyone ever played Rogue on both the CoCo (OS-9) and the IBM
version? 40K code for the CoCo, ~140K code on the IBM, on respective
machines the CoCo version was much faster (except booting - floppy vs. hard
drive is no comparison) and - well - the IBM version sucked. Weren't as
many features, despite the code bloat. Oh, and if anyone wants my custom
font for playing Rogue on the CoCo (stairs look like stairs, scrolls look
like scrolls, etc.) lemme know - I'll spark up the CoCo slide the font file
over to the emulator, so I can put it on the Web sometime. Requires 512K.

So... Did I fill 1999's quota for drivel yet??? ;-)

See ya, and happy new year,
Roger "Merch" Merchberger
=====
Roger "Merch" Merchberger -- zmerch_at_30below.com
SysAdmin - Iceberg Computers
===== Merch's Wild Wisdom of the Moment: =====
for (1..15) { print "Merry Christmas\n"; }
(from perl.1 man page, version 4.)
Received on Fri Jan 01 1999 - 23:16:13 GMT