Re: What Apple II cards used the $c800 ROM address space

[Don Bruder <dakidd@sonic.net>]

In article <f33567e7.0405191038.4ec6a81e@posting.google.com>,
 rdoerr@bizserve.com (Robert L. Doerr) wrote:

> Hello,
> 
> I have been trying to get an old Apple program that requires
> SuperSerial card support to run within an emulator.  So far it seems
> that they emulate a subset of features but do not fully support all
> the features of the SuperSerial card.
> 
> After seeing how creative the authors of the emulators are and all the
> other custom cards like the mocking board being emulated I am sure
> there must be a way to get this to work.
> 
> With the help of some others it appears that some of the trouble is
> that the SuperSerial card uses some ROM space at $c800 which from what
> I have been reading is bank switched and may also share that space
> with other I/O cards.  What other cards would use this area?  Does
> this sound correct or might I be looking in the wrong direction?

What other cards would use this area? THE MIND BOGGLES!!! 
Chances are high that darn near every card uses it to some degree. Any 
card with more than 256 bytes of ROM aboard definitely does. 

Here's where I get foggy, working from memories of long ago "intense" 
Apple II hacking, but I believe this is correct:
"Main" $C800 gets switched out, and the corresponding ROM at $Cx00 gets 
switched in anytime a $Cxyy (x = Slot# * 16, yy = anything) address 
shows up on the address lines. "Main" $C800 gets switched back in when 
$CFFF hits the adress lines.

-- 
Don Bruder - dakidd@sonic.net - New Email policy in effect as of Feb. 21, 2004.
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