[Coco] What would a CoCo successor have to have as a minimum?

Mark McDougall msmcdoug at iinet.net.au
Tue Nov 23 02:25:06 EST 2010

On 23/11/2010 5:30 PM, Steve Bjork wrote:

> Now, most of my CoCo game never ran at 60 FPS because of the speed of the
> coco and the work that was needed per game frame. But the CoCo was design to
> be a cheap home computer that could do many things. An arcade game (like
> Zaxxon) was design to play just one game with hardware tuned for just that
> task and at cost 25 times higher.

Absolutely. Take Frogger/Galaxian (same hardware). There was almost nothing 
that the CPU had to do on the graphics side of things, except adjust a few 
scroll registers and 'animate' a few sprites by changing the sprite index in 
a sprite register. Generating sound simply involved writing a sound effect 
value to a port for the 2nd CPU to play, and then getting interrupted when 
it had finished.

No need to tell you Steve what has to be done on a home computer - the CPU 
itself has to move big chunks of memory to make the cars, logs move. Not to 
mention overlay sprites in software. Then interleave sound/music routines on 
top of that! Even reading keyboard/joystick input is more computationally 


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

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