Re: 6809 assembly knowledge needed

From: Rainer Buchty <>
Date: Thu, 4 Feb 2010 11:38:31 +0100 (CET)
Message-ID: <alpine.DEB.1.10.1002041125180.6429@athlon>
On Wed, 3 Feb 2010, wrote:

> - I assume that the FPGA is big enough for replacing the 6510, how 
> much room is left for extra goodies? (that is my purpose, otherwise it 
> makes no sense to use this device)

When I did my last "Xilinx Professor Training" course we used X2S200 and 
X2S400, the latter being big enough to hold an entire embedded Linux 
system consisting of Microblaze (32-bit RISC), Ethernet, and UART 

The X3S500E should therefore be plenty for 8-Bit hacking, even if the 
6809 model might be not as streamlined as the Microblaze; IIRC a X3S200 
is enough to hold an entire System09 (i.e. the full system, not only the 

> - The PDF says: "I/Os are not 5V tolerant". I see a lot of resistors 
> to handle this. But is it still capable of driving the C64 plus some 
> extras? If not, what is needed to make it capable? For example, will 
> 74HCT245's and 541's do?

You don't need extra level shifters as GODIL comes readily equipped with 
such. These you can use (adds 700ps to the timing path), but you don't 
need to in case you don't require 5V tolerance.

> - I'm not a newbee but I'm more famliar with Altera. What is needed,
> hard- and software, for programming it?

Xilinx ISE Webpack should be sufficient.

(Personally, I don't have Altera experience, but from comp.arch.fpga I 
get the feeling that Altera does a somewhat better job when it comes to 
the general usability of their software.)

>> Plus, 6502 and 6809 are almost sourcecode-compatible, so ....
> Hmmm, nice idea! If I find the time, I'll give it a good thought.

Maybe there's even stuff existing; at least I remember reading an 
Elektor/Elektuur article back in the days where they especially 
announced this kind of source-code compatibility.

Btw., if there are special feature requests or ideas for improvement 
regarding future versions of GODIL, let me know and I'll happily forward 
it to Mike Randelzhofer, the developer of GODIL (whom I'd like to thank 
for donating me first-batch sample).


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Received on 2010-02-04 11:00:03

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