[Coco] DECB -> Pi2/3

[Dave Philipsen]

Yes, you're probably right.  I don't know that anyone has dis-assembled 
OS9000 or has the source.  And I agree with you, it would be a cool 
think to another processor.  Although I'm not sure whether another 8-bit 
processor exists that has the requirements of position independence and 
reentrancy.  And I personally *would* understand why you'd want to port 
it to the TAPR!

Somewhere there does exist a document which describes the minimum 
hardware required to implement OS9.  Probably the first place to start 
would be with Level 1 if that actually exists in the NitrOS9 archives (I 
think it does).  That is simpler and wouldn't require an MMU.  I think 
Neal Crook has a version of Level 1 running on a Multicomp board which 
is an FPGA-based 6809 design but definitely not a CoCo.

Dave



On 3/6/2017 4:58 PM, Bill Gunshannon wrote:
> ________________________________________
> From: Coco [coco-bounces at maltedmedia.com] on behalf of Dave Philipsen [dave at davebiz.com]
> Sent: Monday, March 6, 2017 4:37 PM
> To: CoCoList for Color Computer Enthusiasts
> Subject: Re: [Coco] DECB -> Pi2/3
>
> You know about OS9000, right?  It was an OS9 derivative from Microware
> that was written in C and compiled to run on 80x86, Power PC, and 68000
> platforms.  There's probably no reason that it couldn't also be made to
> work on an ARM machine too.  I wrote some software back in the 90s that
> ran under OS9000 on an 80486 but it was compiled C code, not directly
> written in assembler.  I still have the install disks for OS9000 but I
> don't know if they're good.
>
> _______________________________
>
> Sure, but what good does that do any of us?  It's not free.  It's not available in
> source so it certainly isn't portable.  It runs (or is it ran now?) on a very limited
> hardware set (the PC version did not run on all PC's we tried it at the University.)
> And probably worst of all, it was bloated.  One of OS-9's strengths was the size.
>
> Maybe when I understand the inards better I will try once again at porting it
> to something else.  But right now I am not even sure what would constitute
> a minimal functionaing system.  (I also have another 6809 based box I would
> love to have it on for reasons most people here probably would never understand,
> the original TAPR TNC 1)  :-)
>
> bill
>