[Coco] Question re: Cart slot decode

Gene Heskett gene.heskett at verizon.net
Mon Feb 2 22:08:10 EST 2009


On Monday 02 February 2009, Roger Taylor wrote:
>At 07:16 PM 2/2/2009, you wrote:
>>On Mon, 2 Feb 2009, Darren A wrote:
>>>>On Mon, 2 Feb 2009, Stephen Castello wrote:
>>>>
>>>>I guess that settles it.  There's a considerable quantity of erroneous
>>>>information out there, as I read about four different resources that
>>>> claim the SCS range is ff40-ff5f.
>>>
>>>---
>>>
>>>Settles what?
>>>
>>>The SCS range is FF40 - FF5F.
>>
>>I was confusing myself.  I understand now that the SCS range is
>>FF40-FF5F, but all accesses between FF40-FF7F will enable the bus
>>transceiver on the MPI and allow data flow back and forth. (As will
>>assertion of CTS* and/or SLENB*).
>>
>>Wrong terminology on my part.  The fact that other types of hardware
>>sit above FF5F is orthogonal to the fact of where the SCS are lies.
>>
>>I'm still learning the CC3.  If this were an Apple 2, I'd have this
>>level of detail engraved on the inside of my eyelids :-).
>>
>>Steve
>
>Can't a pak also just decode directly from the address lines?  Aren't
>the SCS and CTS signals just shortcut decoders and also annoying in
>that they ghost the addresses?

Yes it can Roger.  AFAIK, all packs out of the SCS range do a full decode 
internally.


-- 
Cheers, Gene
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
But Officer, I stopped for the last one, and it was green!



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