Re: Hardware emulation of 6509 using 6502?

There was a 24K ram cart for the CBM-II series. It adds 24K into bank 15. I wonder if the P500 could use that ram for graphics/sprites?
IMHO, Commodore should have fully populated BANK 15 with 64K ram and made it possible to bank out the ROMs as the C64 does. This would have made the machines 100 times more useful and would have allowed large programs to run without all the overhead required to access kernal routines from other banks.
Steve

      From: Mia Magnusson <mia@plea.se>
 To: cbm-hackers@musoftware.de 
 Sent: Monday, March 5, 2018 3:51 PM
 Subject: Re: Hardware emulation of 6509 using 6502?
   
Den Fri, 2 Mar 2018 21:56:29 +0000 skrev smf <smf@null.net>:
> On 02/03/2018 21:48, Michał Pleban wrote:
> >
> > No, it can see only bank 0.
> 
> You can have the video matrix in sram in bank f & the colour ram is 
> always in bank f.

According to the 4256041 schematics, page 15, the enable signal for the
sram, called _VIDMATICS_, is enabled when A15, A14 and A12 are high and
A13, A11 and A10 low, ie $D000-$D3FF

That wouldn't overlap with $0/$1.
 
> You can't do sprites or chargen/bitmap in bank f, it's real nasty.

Well, the limit is that you can only access 1k in bank F, but there
seems to be no special limit on the usage of that 1k. Usually it's
probably best to use it for screen ram but in theory you could store
sprite data there instead, or whatever you want to have there.

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