[Coco] [magervalp at gmail.com: Re: 6809 assembly knowledge needed]

[David Linsley]

On Thu, Jan 7, 2010 at 6:14 AM, Gene Heskett <gene.heskett at verizon.net>wrote:

> On Thursday 07 January 2010, John W. Linville wrote:
> >Cool comment regarding 6809 on the cbm-hackers list -- I thought
> >y'all might enjoy...
> >
> Chuckle.  Having looked at the available architectures circa 1982-5, I was
> convinced long ago that both the z-80, 8080 and the 6502 variants, were
> quite
> drain bamaged, and that the 6809 was by far the smartest cpu around at the
> time.
>
> There are some other odd architectures out there, the 1802 from RCA, and
> the
> 9900 from TI come to mind.  The 1802 wasn't a pic processor but could have
> been made that way by careful but slow programming.  I didn't use that
> however when I wrote an application for an 1802 that survived in the
> KRCR-TV
> control room for over 15 years.  The 9900 used local memory for its image
> of
> its registers, and could switch contexts in a single instruction simply by
> reloading its register pointer to a different process's register image.
>  The
> stopped process had no knowledge that it had been stopped, even if the
> stoppage was weeks in duration.  When resumed, it simply resumed at the
> next
> instruction fetch.
>
> The advent of PIC programming was, IMO, a watershed moment in computing
> history.


Even Bill Gates thought the 6809 was the best 8-bit. From
http://americanhistory.si.edu/collections/comphist/gates.htm

"BG: Microsoft started focusing on developing 16-bit software as early as
1979. We decided that what Intel was doing with their 8086 was really the
way to go. Actually, Motorola had played around with the 68000 design and
decided not to go forward aggressively with that. Instead, they did the best
8-bit processor ever done, the 6809. And we did a BASIC for that. I liked
that chip. "

Finally with AMD's x64 instruction set we have PIC in the Intel world!

Cheers,
David.