[Coco] 6809 / General CPU question

[Steve Bjork]

Mike,

Vector space ($FFF2 to $FFFF) is ROM (not ram) because of the memory 
controllers used in the CoCo.

To really understand how the 6809 works in the CoCo you need to know how 
the other chips in the computer work.

I could do a full day Class (if not week) on just how the 6809 sees its 
RAM, ROM and hardware interface ports inside a CoCo3.

Steve (Zaxxon) Bjork

On 2/19/2011 3:46 PM, Mike Rowen wrote:
> Thanks everyone for your responses. Ok, so whenever the CPU powers on 
> or experiences a RESET inturrupt, the CPU will read the contents of 
> FFFE & FFFF and load it into the program counter register. It then 
> fetches instructions from that location. Presumably this would be a 
> location in ROM.
>
> How does an address get into FFFE & FFFF when the system is 
> initialized? Is this through hardware? Are these RAM locations?