[Coco] MC6829 Memory Management Unit

[RETRO Innovations]

On 10/10/2022 10:29 PM, Walter ZAMBOTTI via Coco wrote:
> Would that technique allow the video circuitry to access all the 2meg 
> of mem as well?

GIME video uses a "flat" memory model, as I recall, where the data is 
placed in the physical memory space 0-512kB regardless of task 
mappings.  So, to extend the GIME to allow 2MB of memory access, you 
just create a register with 2 bits, and those 2 bits are used as a video 
"bank" register.  The GIME can only access 512kB at a time, but it can 
access it anywhere within the 2MB memory address space, with the 
requirement that memory access cannot span 2 512kB banks.

Jim