[Coco] CoCo monstrosity |was: [OT] Atari 8-bit video card

[Andrew]

I think if I were going to do something like this - that is, interface 
something to the CoCo bus to generate video - rather than an FPGA, I 
think I would actually go for something like an ATMega644, ala Uzebox. 
Basically, pare down the Uzebox software to the bare-bones graphics 
stuff, perhaps with a few extra routines so you could command and 
off-load things (so, for instance, you could load up a "sprite", tell it 
move in a certain direction, then raise an interrupt on the bus on a 
collision or something like that?). That way, rather than having the 
6809 in the CoCo do all the processing, you can offload the graphics 
stuff to the 644, and use the 6809 for other processing. In fact - if 
you made that board a dual 644 system, one could be used for sound, 
while the other is used for graphics, with the CoCo acting as main 
processing, graphics, disk interfacing, etc. The nice thing about the 
644 is that it's a DIP part, meaning a simple 2-layer DIY soldering job 
as a kit, if you made something and sold/published it. Alright - fairly 
pie-in-the-sky - and you wouldn't make money or such - but it might be 
pretty fun to do nonetheless...

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Andrew L. Ayers
Glendale, Arizona
http://www.phoenixgarage.org/