Re: Hardware emulation of 6509 using 6502?

From: Segher Boessenkool <segher_at_kernel.crashing.org>
Date: Sun, 25 Feb 2018 13:06:20 -0600
Message-ID: <20180225190620.GO21977@gate.crashing.org>
On Sun, Feb 25, 2018 at 06:39:52PM +0100, Michał Pleban wrote:
> Michał Pleban wrote:
> 
> > However, it is possible that these locations ARE corrupted but in the
> > current execution bank; since the ROM code always runs from bank $F,
> > corrupting values $F0000 and $F0001 is not a big deal.
> 
> It also brings the reverse problem - if a location $0000 or $0001 os
> being read by the a LDA (xx),Y operation, will it read the CPU register
> or underlying RAM?

On the 6510 it is the CPU register.  I'd assume 6509 is implemented
similarly (but there are no die pictures to compare AFAIK).


Segher

       Message was sent through the cbm-hackers mailing list
Received on 2018-02-25 21:01:58

Archive generated by hypermail 2.2.0.