[Coco] Coco4 thoughts

[jdaggett at gate.net]

On 4 Jan 2009 at 2:53, BookWorm wrote:

> Are you putting the RAM *inside* the new GIME? That woud be perfect.
> 

No. RAM is external. The FPGA in mind does not have enough internal 
ram for the video section.


> Would the CoCo 4 you're talking about use a 68000 or some imaginary
> new chip? If it's a 68k, why not memory map it in the CoCo 3, and put
> it on a big fat hairy new RAM board? It could share 2 meg with the
> 6809, use your amazing new chip, or the original, and run OSk in a
> NitrOS-9 window. This way we could still have our real CoCo 3, and all
> that "advanced" stuff the 6809 is supposedly "too slow" for.

|===============

My first pass will use a 6809 software compatilbe core that is developed by 
John Kent. It is fully functional and the latest release has cleared most of 
the bugs. The rest is the same as the GIME chip with enhanced video 
section. What will happen is the whole CC3 will fit into one FPGA, 
6809/GIME/PIA chips/serial ports/ mouse and keyboard ports. 

Future pass is to switch to a functional 6309 core. From there do 
enhancements. My vision is to run the 6309 core in a FPGA at a equivalent 
speed of 35MHz minimum. 25MHz is doable. 

james