Re: Amiga, Mac, Atari

[blackm00@cam.org (Michael Black)]

Roger Johnstone <rojaws@es.co.nz> wrote in message news:<20020921120606393+1200@news.inv.ihug.co.nz>...
> In <slrnaomot0.168i.skipper@web1.calweb.com> Skipper Smith wrote:
> > Roger Johnstone <rojaws@es.co.nz> wrote:
> >>
> >>WDC are the creators of the 65C02 and the 65C816.
> >
> > Actually, they (under that name) weren't.
> >
> > Motorola created the 6800.  A few designers walked out the door with
> > the masks to it and started a company called MOS Technologies and made
> > a chip called the 6500.  Motorola sued MOS Technologies.  A judge
> > decidedthat since Motorola made no attempt to secure their
> > intellectual property, the 6800/6500 would from then on be considered
> > public domain.  Motorolans have had to have the contents of their bags
> > perused upon entering or exiting Motorola property ever since.
> >
> > MOS Technologies did a respin of the 6500 to make the 6502 (Motorola
> > also did a respin) so that they could have proprietary rights to what
> > they were selling.  They also started other more complicated designs.
> > Then, for some reason, decided to sell themselves, lock, stock, and
> > barrel to CBM.  Commodore renamed that part of the company to
> > something I can't remember, and proceeded to completely abuse the fab (
> > personal opinion).  Nintendo decided to use the 6502 in their original
> > game machine.  Found out that parts of the design were in the public
> > domain and proceeded to make a duplicate of the 6502 but without the
> > proprietary information and thus avoided giving CBM a single penny of
> > licensing fees that probably could have kept CBM afloat in bad times (
> > but more likely would have just been siphoned off by Mehdi Ali and
> > Irving Gould).
> >
> > When Commodore went bankrupt, their physical equipment was sold at
> > auction.  Those parts that had originally been part of MOS
> > Technologies along with the IP that was part of the 65XX family then
> > went on to become "Western Design Center".  Everything they say about
> > the estimates for sockets inhabited by 65XX parts is pretty reasonable,
> > though.
> >
> > This is all IIRC, but based on my association with Motorola and CBM
> > and discussions with Dave Haynie, so take it for what it is worth.
>
> That's basically the way I've heard the story too, but WDC (which is
> basically William Mensch) did create the 65C02 (the enhanced CMOS chip)
> and the 16-bit 65C816.
>
> From what I remember one of the chips (6501?) was pin-compatible with
> the 6800, not just bus-compatible like the other 6500 chips. Was this
> ever actually sold, or did they have to can it for legal reasons?
>
There's enough misinformation in this thread that I'm not fully
sure where to reply.

I dug out Byte for November 1975, it was only the third issue.
Right on the cover was "A $20 Microprocessor?" and that sure got
the attention of a lot of us.

Inside, the article on page 58 is titled "Son of Motorola (or the
$20 CPU Chip)".  Oh baby, now we can afford to build a computer.

It describes the 6501, a 6800 hardware compatible but not software
compatible, CPU.  You were supposed to be able to plug this one into
any socket that used a 6800, and so long as you had software, it would
work.

I don't know where the mask business comes into play, because this
isn't a 6800.  Some of the instructions were the same, but then things
like branch would have to be.  The 6501 had some different instructions.
And since the architecture was not the same, no B accumulator for
instance, there could be no compatibility.

It runs some instructions in fewer cycles, and it mentions that
Mos Technology is hinting that it can with a faster clock speed
than 1MHz.

There are some subtle hardware differences between the two.

It mentions that it needs an external clock, just like the 6800 it
was supposed to be pin compatible.  There is a reference to the
6502, to sell for $25, which includes the clock.  As Mos points
out, despite being five dollars more, it may be a better choice
because you don't needed the external circuitry.  It makes no
mention of other differences on the 6502.

This article mentions the Western Electronic Conference
(September 16-19) where the 6502 would be sold out of a hotel
suite, but in the future tense.  Since that seems to be
the time when various people first got a 6502 (including Steve
Wozniak), I am suspicious about whether the 6501 ever made it
to production.

My 1976 copyright edition of Adam Osborne's "An Introduction to
Microcomputers, volume II" has no mention of the 6501, though
it does describe the chopped down variants (but not the 6507).

If I could remember some clue, I could find the info about what
happened to the 6501.  I know that Byte ran a brief article some
months later.  Motorola did take offense at the 6501, but since
it wasn't even an extension of the 6800 (as the Z-80 was an extension
of the 8080), I suspect the only thing they could complain about
was the same pin-out.  Certainly, that was what I remember reading.
If there ever was a 6501, it was available for a very brief time
and then disappeared from references.  Which suggests that MOS
was either sufficiently threatened, or outright forced, to withdraw
it from the market.

As for WDC, I'm still thinking about where to look.  A websearch
turns up their page and says they started in 1978.  I thought
they first produced some pretty exotic CPU's but I may be mixing
them up with another company.  They were originally a "design
center", in that they didn't release products themselves.  They
came up with the CMOS version of the 6502; I don't know how
that came about but remember there were at the time second-sources
for the 6502, such as Rockwell and Synertek.  Indeed, it was
those other companies that were the ones that produced the
first 65C02's and there were at least two different versions of
it.  Obviously by the time they came up with the 16-bit CPU that
included the 6502 as a subset (a software bit switched between
CPU's) they were actually releasing their own products.

There seems to be more of a case for WDC stealing from MOS Technology,
since it kept working on the 6502, than MOS stealing from Motorola,
though I suspect that wasn't the case.

And since WDC started in 1978, and had 6502 variants in the early
eighties, I don't know where Commodore's bankruptcy, which came in
the late eighties or early nineties, fits into the WDC scenario.

    Michael