Re: Hardware emulation of 6509 using 6502?

From: Jim Brain <brain_at_jbrain.com>
Date: Sat, 4 Nov 2017 14:48:25 -0500
Message-ID: <f696c43f-a6fa-df7e-6fdf-9668692a54be@jbrain.com>
On 11/4/2017 1:13 PM, Michał Pleban wrote:
> Hello!
>
> Mia Magnusson wrote:
>
>> Maybe this is a bit too hard to actually do, but my idea is to keep
>> track of what the CPU does and detect the LDA and STA Y-indirect
>> instructions and then temporarily switch in the relevant bank during
>> the correct cycle.
> I don't think that it should be difficult. The 6502 emits SYNC signal
> when it is fetching a new opcode. It can then be checked if it's LDA/STA
> (xx),Y opcode and appropriate memory bank can be switched. Nothing a
> CPLD could not solve.
>
> Regards,
> Michau.
>
>         Message was sent through the cbm-hackers mailing list

http://www.go4retro.com/downloads/Fake6509/

Given that the 6509 has the AEC behavior of the 6510, I believe you'll 
need a 65C02, which is what I used. Someone still has to write the HDL, 
but I think the 6502.org discussion Steve linked should give folks what 
they need.

Jim



-- 
Jim Brain
brain@jbrain.com
www.jbrain.com



       Message was sent through the cbm-hackers mailing list
Received on 2017-11-04 20:00:02

Archive generated by hypermail 2.2.0.