[Coco] CoCo 32k rom architecture

[Robert Gault]

OK, after writing an ml routine to print data to the screen I can report what a 
Coco3 sees in the external ROM with 16k / 16k internal external and 32k external.

The most reasonable way to present this is that the 32k ROM always exists from 
$8000-$FF00 and when the Coco3 is in standard 16k internal 16k external mode, it 
sees the second half of the external ROM.
So my program when using 16k/16k saw the Extended Basic ROM at $8000 and the 
second half of the cart ROM at $C000. When the program set 32k external, then it 
saw the first half of the external ROM at $8000 and the same data (second half 
ROM) at $C000.
Can I prove that a ROM reader would see the same thing? No I can't, but I expect 
it would. It makes sense because it is the only way a 32k ROM would not get lost 
when switching from 16k/16k to 32k external.

And then how does this relate to .ccc files? These files do NOT present the ROM 
as seen by a Coco3. The halves are reversed with the second half preceding the 
first!
This makes no sense to me but someone must have decided that one of the 
emulators JVC, MESS, or VCC could handle a 32k ROM cart more easily in this 
fashion. That format then became the standard for .ccc files regardless if it 
was reasonable.

Robert