[Coco] 6309 microprocessor project 01-28-2004

[Robert Gault]

John Collyer wrote:
> 6309 microprocessor project:
> 
> Hello,
> 
> I am working in the memory part of the program, and I added support $FF7F
> Multi-Pak Interface Register.
> There are four slots and each slot can be either 16K or 32K external rom.
> Of course this means that now
> I am supporting (Paul T. Barton's NoCan 16MB Interface.)  Instead of the MMU
> extension registers being
> located at $FF70-$FF7F they are now located at the NoCan locations
> $FF80-$FF8F.
> 
> I would also like to add support for banked switch 16K or 32K rom
> cartridges.  I not sure how to do this,
> but I have eight 16K banks and eight 32K banks.  I think I'll need a flag to
> let me know this is a banked
> switched rom and monitor $FF40 FDC register for any write page number
> requests.
> 
> 
> John Collyer
> 
> 

John and Roger,

I'm not sure why Paul has not replied to this thread unless it is 
because he can't tell from the subject line that the Nocan is the topic.

I own one of Paul's boards, Nocan3 and helped him with software testing 
during the development stages. It is only 8Megs and I think Paul got up 
to 64Megs.

I can tell you why I did not modify any of my programs to use the extra 
memory. I had no idea how many people bought these boards and did not 
want any software I sold to require exotic hardware. Nitros-9 can't yet 
use this extra memory because it would take a major rewrite of the 
system core to handle the addressing. There does not seem to be any good 
place to but the MMU block address table.