[Coco] Coco4 thoughts

[Joel Ewy]

BookWorm wrote:
>> 480Kbytes. Inside the FPGA this is easy to do.
>>     
>
> Are you putting the RAM *inside* the new GIME? That woud be perfect.
>
> Would the CoCo 4 you're talking about use a 68000 or some imaginary new chip? 
> If it's a 68k, why not memory map it in the CoCo 3, and put it on a big fat 
> hairy new RAM board? It could share 2 meg with the 6809, use your amazing new 
> chip, or the original, and run OSk in a NitrOS-9 window. This way we could 
> still have our real CoCo 3, and all that "advanced" stuff the 6809 is 
> supposedly "too slow" for.
>
>   
A 6809 core running at an effective clock rate of about 21MHz would
probably give an 8MHz 68000 system (Atari, Amiga, original Macintosh
come to mind) a run for its money.  And if you had a 16-bit data path to
memory the 68K wouldn't even get points for bus width.

I've got a Digilent Spartan 3 1000K board on the way, so I'm going to
try out Gary Becker's FPGA CoCo 3 soon.  I'll put up a blog detailing my
experiences.

I really want to run some programs that take a lot of time on the CoCo
and see what they feel like at approx 21 MHz.  Particularly things like
decoding GIF files, and Sockmaster's HiColor display.  The latter might
be a challenge because the timing will be completely off at the higher
clock rate, and I'm not sure what the VGA timing will do to it as well. 
Oh, and then there's the fact that the CPU09 doesn't use the same
instruction timing as a real 6809.  But I could certainly see how long
it takes to process the image, and with a little work, adapt Sock's
program to the CPU09.

More to come when I get my development board...

JCE
> --
> Coco mailing list
> Coco at maltedmedia.com
> http://five.pairlist.net/mailman/listinfo/coco
>
>