On 6/1/2012 2:46 AM, A2CPM wrote:
Hi, y'all!
Interested in the 6809 CPU? Then you should join the Apple6809
group I started. Email me privately for an invitation...
Willi
Let's stay here. If there are any files to share I'll put them on my web page if needed.
At one point I looked closely at the Mill card thinking it should not be too hard to make a configuration for the Carte Blanche to emulate it. For the first test I used a real 6809 [ab]using a 500,000 gate FPGA to replace a few hard gates on the board. So a demo from the Mill floppy counted numbers on the screen. Not very exciting. So I made a configuration with an emulated 6809 (at 25 MHz) running on CB instead using the design by John E. Kent
http://members.optushome.com.au/jekent/system09/index.htmlClearly the emulated 6809 could be slowed down by a factor of 25 and share the memory with Apple 2 ... not very exciting IMHO. If 10 people wanted a clone of the Stellation Mill card, I could make the boards using real 6809E CPUs available from Jameco.
Now a much more interesting project would be to combine System09 on a chip with an Apple bus interface similar to the PCPI card, so that the 6809 could run at full speed and use 256 KB or RAM and the IDE hard disk. The problem is that there are a very limited number of CB cards in the world and also somebody needs to write the drivers for both the Apple side and the 6809 side.
John's project has been ported to a number of inexpensive FPGA boards including my personal favorite Altera DE1 ($150). That is probably the easiest way to play with a configurable 6809 system short of a software emulator. BTW I made an Apple 2 configuration for DE1 quite a while ago.
-Alex.