Groups > comp.sys.apple2.programmer > #299

Re: standard interface to aux RAM or RWIII RAM?

From	aiiadict@gmail.com
Newsgroups	comp.sys.apple2.programmer
Subject	Re: standard interface to aux RAM or RWIII RAM?
Date	2012-05-12 15:58 -0700
Organization	http://groups.google.com
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On Saturday, May 12, 2012 3:31:38 PM UTC-7, aiia...@gmail.com wrote:
> 
> http://vinace.sourceforge.net/en-x187.html
> 
> Low 4K requests ($D000-$DFFF) are connected to RAM at $D000-$DFFF if LCBNK2 is set or to RAM at $C000-$CFFF if not.

> Ok, so there are two 4k RAM areas that can be switched into D000...
> 
> is this on the motherboard?  on the 80 column card?
> 
> Does each aux bank have it's own alternate 4k area for D000?
> 

I see now....

MAIN RAM has two 4k segments it can map to $d000...

the segment which resides at $D000, and the segment
which resides (or ?should?) at $C000.  ROM is mapped
onto the bus when $C000-$CFFF are accessed.  So the
RAM that is "missing" can be switched into $D000.

I was wondering where the missing RAM is.  

It makes sense that each aux bank would do the same,
I'll have to test it.

answered my own question, using the VINACE emulator
documentation..  Ive never seen the information
presented this way.

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standard interface to aux RAM or RWIII RAM? aiiadict@gmail.com - 2012-05-10 18:07 -0700
  Re: standard interface to aux RAM or RWIII RAM? David Schmenk <dschmenk@gmail.com> - 2012-05-10 19:41 -0700
  Re: standard interface to aux RAM or RWIII RAM? aiiadict@gmail.com - 2012-05-11 09:31 -0700
    Re: standard interface to aux RAM or RWIII RAM? aiiadict@gmail.com - 2012-05-11 17:42 -0700
      Re: standard interface to aux RAM or RWIII RAM? aiiadict@gmail.com - 2012-05-12 15:31 -0700
        Re: standard interface to aux RAM or RWIII RAM? aiiadict@gmail.com - 2012-05-12 15:58 -0700
          Re: standard interface to aux RAM or RWIII RAM? "ict@ccess" <gids.rs@sasktel.net> - 2012-05-21 20:53 -0700
            Re: standard interface to aux RAM or RWIII RAM? aiiadict@gmail.com - 2012-05-25 16:19 -0700

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