[Coco] Utility of large MPI

[RETRO Innovations]

On 2/2/2016 12:33 PM, Camillus wrote:
> Why not integrate the diskcontrollers ( floppy, ide, etc, etc ) straight into the coco design, so that the range FF40-FF5F can be used solely for cartridge I/O. There has to be a chunk of 16 addresses somewhere in the coco's memory map that can be decoded for the controllers?

Even if you find 16 (probably 32) registers to stow all of these things 
that are not in the $ff40-7f space, they won't work unless someone 
rewrites code to use them at their new addresses.  That's a huge 
undertaking.  And, I can't go there because my 6809 assembly skills are 
sub-par at best.

On the other hand, putting all of that stuff on a single cart means they 
can all coordinate use of the bus, folks can use it with or without an 
MPI, and MPI users can use it as one of the 4 slots, freeing up 3 slots 
for other stuff that is less ubiquitous.

Jim