[Coco] Coco 3 Memory Map Questions

Robert Gault robert.gault at att.net
Tue Feb 9 08:52:42 EST 2016


Arthur Flexser wrote:
> I believe the $FFFx vectors were in fact mapped to $BFFx in the earlier
> CoCos. So this is apparently not true in the CoCo 3, then?  Does $BFFx in a
> CoCo 3 therefore contain unused leftover vectors?
>
> Art
>
> On Tue, Feb 9, 2016 at 12:22 AM, William Astle <lost at l-w.ca> wrote:
>
>> On 2016-02-08 18:00, RETRO Innovations wrote:
>>
>>> I can say there would be some value in someone who could combine GIME,
>>> GIME2, LOMONT, Service Manual, Sock's GIME registers, etc. into a single
>>> locaiton with a common layout.  As someone trying to get familiar with
>>> the platform, it is difficult to sort through the various resources to
>>> get to consistent and accurate data.  I see now where Darren picked up
>>> his list from (it's listed on 2 lines on GIME.txt),
>>>
>>
>> That would be useful even for folks that already know the platform,
>> actually. I find I have to look things up all the time myself.
>>
>> To cap it off, there are bits that are not listed in the "usual" places,
>> like the "64 column 'VDG' screen" I wrote about some years ago on the list.
>>
>> There is also bad information on exactly where the FFFx vector area is
>> mapped. As I recall, Lomont asserts that it is mapped to BFFx when, in
>> actual fact, it maps to the upper 16 bytes of the internal ROM regardless
>> of ROM or RAM mode, something I confirmed experimentally a while back when
>> I was messing with ROM replacements.
>>
>> I'm sure there are other bits of information like that floating about in
>> random places like Sockmaster's brain, comments in the Mame source, etc.
>>
>> --
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>> Coco at maltedmedia.com
>> https://pairlist5.pair.net/mailman/listinfo/coco
>>
>

ExBasic 2.0 has interrupt vectors at $BFF2-$BFFE pointing to the actual vectors 
at $FFF2-$FFFC. SEB has another set of vectors at $FEEE-$FEFF pointing to $100-$109.

Robert



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