Re: Assemblers for the 65816 processor

From: Greg King (
Date: 2003-12-02 05:51:15

From:; at Date: Monday, December 01, 2003, 10:32 PM
> > From memory, it is $d3xx (or, was it $D2xx?).  So, it uses what C64
> > normally mirrors the VIC to.  I guess you do it quickly so no
> > accidental writes.  There may be some I/O reasons, too, which the CPLD
> > addresses.
> There's RAM at both, but the $D2xx is supposedly reserved for use by the
> "system," and the $D3xx page is available for users.

As far as I could tell, the "system" is GEOS -- the SuperCPU driver puts
short subroutines there which control the SuperCPU's registers.  I think
that the SuperCPU's ROM does not use those pages.  So, both pages are
available when you are not using GEOS.

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