> Dear PICsters,
> I am trying to wrap my head around the paging system that the '505 uses.
If
> I understand correctly, the memory is banked into four arrays of around
255
> bytes each. A call from the first bank to the second or third bank seem to
> wrap around the program counter or something which means the program
somehow
> finds its way back to bank 0 . Does anyone have some tips or can explain
> this phenomena to me please? I would really appreciate it. Many thanks.
>
>                                 Regards John

I don't know the '505 specifically but, the banks of RAM have addresses, say
from 0 to 255. Even though there are 4 banks of 256 bytes, they don't number
from 0 - 1023.  they number from 0-255 bank 0,  0-255 bank1,  0-255 bank 2,
and 0-255 bank 3.

If you do something like collect data sequentially in a buffer, starting at
address 0,  bank 0, eventually, the pointer will get to the 255th address.
The next byte will go into address 0, bank 0 again because  1) the address
counter will 'roll over' from 255 to 0, and 2) the bank # is controlled by
YOU the user.


Hope this helps.

Tony