Re: 6809 / 6702 puzzle

From: Mike Naberezny <>
Date: Wed, 11 Apr 2012 23:06:33 -0700
Message-ID: <>
Hi Ruud,

On 4/11/12 10:34 PM, Baltissen, GJPAA (Ruud) wrote:
> What about creating a device the mimics the 6702 as good as possible?
> Preferably one that can be reprogrammed in circuit? IMHO a much better
> idea then changing programs only to find out that there is still part
> that needs to be changed :)

I saw the snippet that Olaf posted with dongle_values.  If it only needs to 
loop a fixed sequence, how about an EPROM and a counter?  The counter would be 
connected to the address lines of the EPROM and would increment by one on each 
6702 read.  It would also need a little logic to reset the counter at the end 
of the sequence.

 > I already agreed to lend my SuperPET to Olaf so he can study the 6702 in
 > real. And I wouldn't mind if he replaced the real 6702 with such a
 > device.

It seems that the 6702 is only for protection and is only used by the Waterloo 
disks.  It may be easier to remove the protection from the disks than to build 
a replacement.


Mike Naberezny (

       Message was sent through the cbm-hackers mailing list
Received on 2012-04-12 07:00:08

Archive generated by hypermail 2.2.0.