[Coco] A Technical Question

[Mark McDougall]

On 18/05/2012 11:15 PM, T. Franklin wrote:

> 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.

As anyone on this mailing list can attest to, the whole 'Coco4' theme pops 
up about every 3 months. I'm not going to raise that again, but you are 
venturing into familiar territory.

As we all know, one of the issues with such a concept is the differing views 
on what should be done, how it should be done, and on what hardware. This 
has been debated to death and, of course, there is no "right" answer. But it 
does fragment interest within the group.

What I would find interesting is a Coco cartridge that extends the graphics 
capabilities without compromising on compatibility. For example, adding 
tiles and/or sprites, and scrolling layers. It would mean a VGA connector on 
the cartridge itself, but IMHO the "buy-in" would be significant because 
you're still using the stock Coco(3?) hardware. And one could also provide 
extended ROM routines for the new hardware.

Of course, prototyping this on an FPGA would be an ideal project!

I would also note that there's an FPGA plug-in card for the Apple II - 
called Carte Blanche - that has similar potential. It outputs the standard 
Apple II graphics onto a VGA monitor, but could easily be extended to allow 
enhanced graphics. I'm not aware of any effort to do that just yet though.

> 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.

The DE1 is a nice little platform and, although not the largest of FPGAs 
these days, quite a lot can still be achieved on it; the Minimig (Amiga 
500), Zet (8086 PC) and of course Gary's Coco3FPGA are prime examples.

Regards,

-- 
|              Mark McDougall                | "Electrical Engineers do it
|  <http://members.iinet.net.au/~msmcdoug>   |   with less resistance!"