Nitros9 for the masses (was) Re: [Coco] COCO4 Emulator

[farna at att.net]

I understand just enough about programming to realize the differences in emulation vs. porting.  In simpler terms than James Jones put it: with emulation there is a large layer of software that "translates" everything from the emulated system to something that the system the emulator runs on can understand. It doesn't have to pass everything, just what needs to go "through" the emulator to the outside world. The software does everything. That's why it takes roughly a 100MHz 486 to equal a 2MHz CoCo3 -- at least thats what I seem to recall. But even if it's a 50MHz+ 386, it takes a lot of processing power to emulate another system in comparison to the emulated hardware. 

Porting the OS requires communicating directly with the system hardware. As James pointed out, there are lots of differences between Motorola and Intel systems that have to be dealt with. Some ports, such as WINE (I forget the acronym, but its Windows programs running under Linux) aren't really ports. In this case it's the Windows ABIs rewritten to run under Linux. Some system commands have to be emulated, but the majority are ported ot Linux. It's not an emulator, but not a true port either. The result is running Windows programs in a Linux environment, programs like MS Office. But I'm digressing now! 

I understand Boisy's point of view about a "CoCo4". I disagree, however, that it would take Tandy to make it. A natural successor could be built, in hardware, but it would have to have some backward compatability with DECB and at least CoCo3 specific programs. I would think dropping CoCo 2 programs would be a reasonable compromise for added ability -- mainly dropping things like artifact colors, and maybe semi-graphics modes. BASIC programs coule always be tweaked to run on the new machine. But if it doesn't have enough backwards compatibility to run CC3 DECB games cartridges and programs, then it's not really a CoCo4. 

Nitros-9 and OS-9 are nice OSs, but you lose a lot of what makes a CoCo by not having the simplness of DECB. This could be done on totally different hardware with transparent or semi-transparent emulation along with some different interfacing, but it would be better done using a 6809 or 6309 core in an FPGA. The Superboard is the next best thing until someone does that and enhances the display, memory, and storage capabilities of the CC3 without destroying useable backwards compatibility, and without requiring an emulator for backwards compatibility. 

A "compatibility mode" might work, but it would be so much less a CC4 if that was required. If you have to switch modes you may as well run an Intel machine with Windows and use an emulator. Except for interfacing with the machine it's about the same thing. All you need to make your Intel box a "CC4" is an interface board. 

--
Frank Swygert
Publisher, "American Independent 
Magazine" (AIM)
For all AMC enthusiasts
http://farna.home.att.net/AIM.html
(free download available!)

 -------------- Original message ----------------------
> Date: Sun, 7 May 2006 17:19:15 -0500
> From: Boisy Pitre <boisy at boisypitre.com>
> Subject: Re: Nitros9 for the masses (was) Re: [Coco] COCO4 Emulator
> 
> Porting NitrOS-9 to an x86 would be a major undertaking.  So much of  
> what NitrOS-9 is, is because it welds itself to the 6809/6309:  
> registers, memory footprint, etc.  I just can't see it being done in  
> a reasonable amount of time, nor could I see it being done without  
> some major design changes and concessions to the OS itself.
> 
> If one wanted to truly write a NitrOS-9 type OS for x86, it could be  
> done, but in some higher level language such as C.  That said, I  
> don't see how this is anything remotely close to a CoCo 4.
> 
> I've said it before, and I'll say it again: the CoCo 4 is a myth.  In  
> my opinion, the only organization that could have ever put out such a  
> thing as a CoCo 4 would have been Tandy, and they are defunct.  The  
> best we can hope for is a CoCo 3+ (ala the SuperBoard).
> 
> What has piqued my interest of late is getting the 6809 on other  
> computer systems that were conventionally 6502 based, like the Atari  
> XEGS.  A colleague of mine is working on this and I think that would  
> open up some interesting avenues for NitrOS-9.  It's not a CoCo 4,  
> per see, but perhaps another avenue to get other retrocomputers into  
> our fold.
> 
> Boisy