[Coco] No more dream ports (Was:Wolfenstein 3-D on a 4.77mhz 8088? So, 6809 port, anyone?)

[Steve Bjork]

Mark,

While it is true that Xevious had 3 CPUs, (Main, Graphics and sound)  it 
did not need all that power.  The Namco Galaga board was used for the 
following games...
Galaga, Bosconian, Dig Dug, Xevious and Super Xevious.

The hardware designers built the Namco Galaga board for more than just 
the Galaga game.  Since they did not know what games would be using it, 
they over-design to cover any future games.

I don't believe that graphics on the board had any sprites. (Arcade game 
Zaxxon also did not have sprites.)  Graphic work was done of the Charter 
map system to emulate sprites.  This is why they put a CPU in the 
graphic system.

If the number of game objects is kept low then a game "like" Xevious or 
1942 could be done on a CoCo 3.  Since the vertical scrolling technique 
takes 128k just for the screens, you will need a 512k CoCo 3 to run the 
game.

Steve

On 4/24/2013 9:39 PM, Mark McDougall wrote:
> Xevious is my all-time favourite arcade game, and 1942 is pretty high 
> on the list as well. I'd love to see those done for the Coco...
>
> I've always wondered whether Xevious really _needed_ three CPU's, 
> especially given the scrolling, tile and sprite hardware. I figure not 
> because it was ported to home machines with far less processing and 
> graphics power. The NES port, for example, is pretty impressive.
>
> Of course, emulating sprites on the Coco is always going to be the 
> bottleneck...
>
> Regards,
>