[Coco] A Technical Question

[John Kent]

On 18/05/2012 11:15 PM, T. Franklin wrote:
> Thanks all for all the replies. Your responses pretty much told me what I need to know.
>
> In summery, the implementation of the Video/RAM methods is as I thought. There seems to be more than one method and there doesn't appear to be a "standard which was my basic question.
>
> As for the OpenGL that was a general "concept". I agree that implementing a full boat OpenGL wouldn?t be practical but it would be cool to take some of the graphic functionality off the 6809 and put it in a co-processor to free up and speed up game programs. As one of you stated, maybe not OpenGL but perhaps just implement of a sprite engine complete with masking and full screen scrolling along with some basic draw functionality. That would leave the processor to do the game-play aspects. I?m just toying with ideas at this point. I also thought of a possible mode with a 1/2 graphic 1/2 text screen for adventure style games.
>
> Furthermore, yes, I plan on implementing the entire thing on an FPGA. Right now I?m working on the DE-1. There?s no timetable for this. It?s more of a "can it be done and if so. How" type project.
>
There is the Gameuino which is a sprite based graphics engine for the 
Arduino. It doesn't seem to have external memory on the board that I 
could see, so I assume it uses internal block memory to generate a 32 x 
32 pixel sprite. There is not enough block memory in most of the smaller 
FPGAs to cover the entire screen, as Mark McDougall indicated, but I 
think what James ??? Bowman did was re-use sprites to cover the whole 
screen.

I assume his design is pretty similar to the TMS9918A (?). I'd like to 
implement line drawing and area fill in hardware, although I have so 
many other projects on the go at the moment, that I'm spreading myself 
pretty thinly, and I'm having difficulty finishing any of them.

John.

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