[Coco] Doubt about how 68xx interrupt vectors work

[Juan Castro]

Ahhh, thanks. I wonder, if an expansion ROM is present, will the new
contents appear at these last addresses, or the previous ones? I would
imagine you could put new addresses and they would be active.

And I was wrong about the MC-10. The main ROM address is E000-FFFF. I was
peeking idly on an MC-10 and saw those addresses are mirrored at C000-DFFF,
down to the last byte.

(Oh, by the way, I will resume work on CaChars -- thinner font, 64x24 text
-- any day now. I promise. :-P)

Juan

On Sat, Jul 21, 2012 at 9:11 PM, Robert Gault <robert.gault at att.net> wrote:

> Juan Castro wrote:
>
>> The values that are in the very last words of memory, the jump table for
>> the interrupt vectors. In a CoCo, and in an MC-10, where are they
>> physically stored? There's no ROM at these addresses. (Well, there is if
>> you have a ROM expansion, but presume you don't.)
>>
>> Juan
>>
>>
> Interrupt vectors are stored at the end of the Basic ROM at $BFF2-$BFFF.
> The motherboard probably reflects the bytes at $FFF2-$FFFF to the above
> address.
>