6809 SBC

[N0body H0me]

> -----Original Message-----
> From: chd at chdickman.com
> Sent: Sun, 07 Feb 2010 18:47:55 -0500
> To:
> Subject: Re: 6809 SBC
> 
> William Blair wrote:
>> Having learned assembly language programming on the beautifully simple
>> architecture and instruction set of the 6800, the Byte magazine article
>> linked to below that I read when it was originally published really
>> impressed me.  In the 6809 they made one of the earliest efforts I know
>> of to really tweak an already great uP instruction set based upon an
>> analysis of existing software:
>> 
>> http://tlindner.macmess.org/?page_id=119
>> 
> I was introduced to the 6809 when I was at university and it just seemed
> right. I came home and bought a CoCo2 and an EDTASM+ cartridge just to
> play with it. I still have it.
> 
> Is there a source for 6829 MMUs? I would love to build a 6809 SBC with
> an MMU that could run OS-9.
> 
> -chuck

From what little I've managed to gather, the 6829 had some limitations that made it either difficult to use, or otherwise impractical for 
many (if not most) applications.  I've read someplace, for instance, that you were restricted to four tasks.  I suspect for that reason,
they're rarely seen.  They were rare even in their own time.

A better approach, may be to create some hardware to emulate either
a Gimix or SwTPc style DAT (dynamic address translator).  The key
element here, is that both of these are supported by some version
of OS/9.

-Jeff