Re: Hardware emulation of 6509 using 6502?

From: Jim Brain <brain_at_jbrain.com>
Date: Wed, 18 Jul 2018 12:37:25 -0500
Message-ID: <05f69caa-c091-2fd6-7973-a9b6afead08d@jbrain.com>
On 7/18/2018 3:59 AM, Michał Pleban wrote:
> Jim Brain wrote:
>
>> Well, it should not *HAVE* to be rewritten.  It can, though, to support
>> the '816.
> If it's not rewritten, how will it access the DRAM when the 816 is used?
When the unit boots, it boots into 6502 "mode", where $0 and $1 behave 
as before.  Maybe I misunderstand the question.
>
>> On a real 6509, if you store $aa at $0 and read it back, do you get $0a
>> or $aa?
> It will read $0A.

OK, thanks.  That makes creating an 8 bit port version of the 6509 a bit 
tougher, but maybe still doable.

Jim

>
> Regards,
> Michau
>

-- 
Jim Brain
brain@jbrain.com
www.jbrain.com
Received on 2018-07-18 20:03:03

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