[Coco] Kicking the Z-80 butts...

[Mark McDougall]

On 29/04/2015 5:25 AM, J Arcane wrote:

> Video is absolutely the limiting factor with the CoCo, or at least video
> and sound. The 6809 powered some very high quality arcade games in its day,
> but the CoCo lacked a dedicated sound synth, and the graphics support lacks
> the built in sprite and scrolling modes that hardware like the C64 had. So
> you have a very powerful processor, but that processor has to do a lot more
> of the work running a game than it does on something like a C64 or one of
> Konami or Williams' boards.

This. Adding higher resolutions and colour will do nothing but burden the 
6809 further. You only need to look at the NES with (scrolling) tilemap and 
sprite hardware to see how much load that takes off the CPU, and what sort 
of quality games you can produce. I'd venture to say that a Coco with such 
hardware would place it somewhere between the NES and SNES in capability.

The Williams boards with a 1MHz 6809 (after Defender) had a blitter for 
moving graphics around memory, optimised for the video memory architecture. 
Konami's Tutankham only had (split-screen) scrolling, but Juno First had a 
blitter as well.

Of course it's all academic without any software developed specifically for 
it. I firmly believe that adding tilemap/sprite hardware capability to the 
Coco will open up all sorts of possibilities for porting existing, high 
quality games to the Coco. It's far easier to port a game than develop a new 
one, and you don't need to be a commercial games developer to do it. Just 
think about Super Mario Brothers on the Coco!

Regards,

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