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

[Mark McDougall]

On 29/04/2015 10:48 AM, Mark McDougall wrote:

> 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.

Further to this I should clarify that the above mentioned Williams and 
Konami games used bit-mapped graphics with no sprite hardware.

I actually have Tutankham running on the Coco, but with no scrolling 
support and the screen rotated 90 degrees. It does look pretty 
impressive, even as a proof-of-concept.

There has been some debate over whether Defender could be ported to the 
Coco in any fashion. The main issues are resolution and video memory 
layout - Defender has an odd architecture whereby pixels in the same 
byte (word?) of video memory are organised vertically, not horizontally 
as you'd expect.

Regards,

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