[Color Computer] Re: [coco] What would it take to really emulate a coco on a modern PC?

[John Donaldson]

  What I would love to have is what I call a COCO4 emulator program. 
Something along these lines.

COCO4 Emulator

   1. Add 640X480 and/or 800X600 screen support.
   2. Extend the number of colors that can be used at the same time.
      True 64 or 128 colors.
   3. Increase the memory to 2 or 4 MB for both DOS and NitrOS9. Make it
      fully accessible for programming, not just for RAM disks and such.
   4. Change the memory mapping to 2K instead of the 64K
   5. Extend the boot process in NitrOS9 so more drivers can be loaded.
   6. Add support in NitrOS9 for using Ethernet Cards, sound cards and etc.
   7. Optimize the emulator speed to take advantage of the PC CPU speed.
      That is allow it to run as fast as possible.
   8. Make the PC floppy drives Read/Write/format real DOS and NitrOS9
      disks.

With the faster CPU’s of today and letting the emulator run at full PC 
speed, it should be fast enough to handle all of these items.

John Donaldson




Larry Shurr wrote:

>--- In ColorComputer at yahoogroups.com, "George Ramsower" <yahoo at ...> wrote:
>  
>
>> What would it take to really emulate a coco on a modern PC? 
>>This would include a plug in board to emulate all the I/O 
>>stuff a coco has, including the expansion port.
>>    
>>
>
>Hmmm... haven't heard much talk of Coco emulation projects in awhile.
> What would you like to emulate that isn't already available in one of
>a number of readily-available software emulators?  E.g., Mr. Jeff
>Vavasour's excellent Coco II & III emulators (see
>http://www.vavasour.ca/jeff/).  I bought his Coco III emulator years
>ago before it became freeware, though this entailed replacing the 6809
>emulation with unencumbered code which is slightly less efficient then
>the original CPU emulation.  I considered the payware version to be
>well worth its low price.  On a typical modern PC, the small
>performance difference between the payware and the freeware versions
>was effectively subsumed and rendered meaningless long ago by the
>ever-increasing speed of Intel '86 processors. 
>
>It is true that even Jeff's excellent emulations are not bit-perfect
>(The Sockmaster's Bouncin' Ball Demo for the Coco III doesn't work,
>for example) and of course, the little interface projects that were
>once popular with the Coco hardware cannot be done.  Is that what
>you're looking for?
>
>  
>
>> I think this would be an expensive project. I'm sure this 
>>would not be easy. However, this would be really fun to have 
>>a real coco on a PC.  It would be faster than a bullet,, 
>>more powerful than a locomotive,  able to leap tall buildings 
>>in a single bound.....  I hope you get the idea.
>>    
>>
>
>The Vavasour Coco III emulator running on my 2 Mhz P4 laptop can be
>dialed up to run absurdly fast, making the proverbial speeding bullet
>say, "Huh? What was that?"
>
>Many years ago, it was proposed to design and build a Coco 4 which
>would provide backwards compatibility to Coco II & Coco III in some...
>disputed... form.  I say disputed because everything about this
>proposal was disputed... everything.  There was a great deal of
>discussion, some of it quite interesting, but there was more than a
>little flamage and snapping of tempers, as well.
>
>At least one faction declared that the Coco 4 had already been built
>and it was known as the Amiga.  Of course the Amiga had no Coco
>compatibility, nor was there an Amiga-based Coco emulator, but the
>Amiga faction considered it the "spiritual" successor to the Coco.  I
>won't say they were wrong, but even then, the Amiga was effectively
>dead (I realize that the Amiga lives on, after a fashion, in a Power
>PC-based implementation even today, but it's a niche machine and lot
>of people have never even heard of it).  Another faction claimed that
>the Macintosh was the Coco 4... but that idea was pretty much shouted
>down.
>
>Other proposals included a PC-based software implementation and a
>number of hardware-based implementations, both free-standing and
>plug-into-a-PC cards.  Proposed CPU's that I recall were Intel 486 and
>Pentium CPU's (I seem to recall that Intel had a low-cost 486 with
>integral interrupt controller and I/O intended for embedded control
>applications -- sort of a new edition of the 80186), Moto PowerPC
>(fairly expensive at the time), and the Moto "Coldfire," an embedded
>control processor more-or-less based on the 68000 family.  And that
>discussion was just about implementation.  As for what a Coco 4 should
>do, well there was no agreement there, either, though the competing
>implementation proposals dominated the argument.  I liked the Coldfire
>idea and thought it the most serious proposal.  Moto sold a cheap
>design kit that would have made a good starting point that would cut
>down on manufacturing and/or kitting requirements, but I was willing
>to support just about anything that might arise from a consensus. 
>However, looking back on it, the lack of consensus may only have been
>a symptom that there wasn't a critical a mass of support available to
>realize a populist-created Coco 4 in any form.  Possibly, there were
>too many legal encumberences, e.g. Tandy and Microsoft licenses, as well.
>
>  
>
>> I'm sure I'm dreaming.... No.. not sure, certain.
>>
>>    
>>
>
>The available evidence suggest that you're right.
>
>Larry
>
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>
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>
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