[Coco] coco sub 64k memory modes

[Stephen Adolph]

Just to confirm,
If I read what I've seen correctly,

32K bank switching is controlled by 4 registers

FFDE/FFDF  (TY)  defines the use of the upper 32k for either the ROMs or RAM

FFD4/FFD5 (P1)  defines the use of the lower 32k for RAM, when in ROM
ACTIVE (not all RAM mode)

ex.

To set all ram mode, one would  write to FFDF

To set first page of RAM active, and ROMS active, write to FFDE, FFD4


And, to jump into all ram mode, you would (in machine language)
(assuming default 32k operation)

* write to FFD4 (ensure normal P1 setting)
* start loop
* write to FFDE (to go into RAM/ROM mode)
* get a byte D from address A
* write to FFDF(switch to all RAM mode)
* write byte D to address A
* end loop


sound reasonable?

thanks, Steve