CUBIX/6809 updates

Gooijen, Henk henk.gooijen at
Mon Dec 12 02:53:31 CST 2005

  Hello Dave.

True, I used JavaScript to display the navigation tree at the left side.
But the page describing the home-brew pdp8/e running on 6809 is here:

It started with some hardware to connect a (homebrew) console to the
serial port of a computer which runs SIMH. With a few changes in SIMH
you can have bi-directional communication between SIMH and the console
thus give (in this case) the PDP-11 SIMH a "real" console. It does all
that a real console also does, hence the project name "RealConsole".

Also, check out  if you want to
start on 6809. It gives you an "emulator" on your PC, connected to the
6809 target system. The best part is that especially for the 6809, it's
free!  I asked John, told him what I was doing, and I got a license.
You must put some code on the target simple, but it is fairly simple.

As the "pdp8/e" is built on the 6809, it can of course run 6809 code.
In the SIMH version EPROM is a disassembler and a small BASIC
as there was room left in the EPROM. The IDE interface (with adapter to
put in a CompactFlash Card) is connected to the I/O board, so it is not
fast, but gives mass storage. The IDE routines are of course written in
6809 assembler and not pdp8/e code :-)  So, the low-level access
are there as a layer for an OS, etc.
Implementing a DOS (FAT-12) would make it possible to connect the CF
to a PC and get file transfer that way. Pulling  out the CF Card,
it in the PC etc. was not my idea, I liked a floppy disk better for this
job, so I ordered 2793's from bgmicro.

Using the pdp8/e design fron panel for the 6809 is possible, but ...
there are only 15 Address LEDs (12 plus 3 for EMA), and the other row is
12 LEDs, so the upper 4 would not be used. The rotary knob could be used
to display A or B (or DP or CC) but to display X, Y, U, SP, PC you need
16 LEDs. There are just 12 switches, and you could use the SW switch as
the 13th, but still, to enter a 16-bit address would be cumbersome.
So, the pdp8/e panel is not the best choice, but the implementation
-hardware wise- is always possible. Software is what makes it 'tick' :-)
and I am sure that's "piece of cake" for you, Dave.

Recenty I won an HP2117 console panel and a full 11/70 panel on eBay,
I want to connect those two panels with a Core and I/O Board to SIMH
Then there is the resurrection of all my PDP-11 (real) machines now that
I have finally power in the little museum.
It's clear, I have way to many project going ...
When I pick up the 6809 stuff, I will certainly take a good look at your
code, and mention you on my website.

  thanks for sharing great stuff!

- Henk, PA8PDP.

> -----Original Message-----
> From: cctalk-bounces at 
> [mailto:cctalk-bounces at] On Behalf Of Dave Dunfield
> Sent: zondag 11 december 2005 21:27
> To: General Discussion: On-Topic and Off-Topic Posts
> Subject: RE: CUBIX/6809 updates
> > Great Dave.
> > I will soon be picking up the intended floppy disk 
> interface for my 6809 board (Blinkenlight project).
> > I must definately have a better look at your pages! Your site was 
> > already known to me :-) Perhaps I should not put so much 
> work in my 6809 code, but grab yours. But then I'll ask first!
> Hi Henk,
> I've heard about your project, but don't know much about it 
> (Your pages requirement to run code on my machine put me off 
> - even if my browser was modern enough to understand it - 
> which it isn't).
> I was under the impression that in your project the 6809 
> performing emulation and front panel control --- Can you 
> boot/run "native" 6809 code in your design? It would be quite 
> neat to see the system running with a front panel. (One of 
> things I always "wanted to do" was build up a front-panel 
> machine around the 09 - just never did).
> CUBIX no longer has commercial value, and I've made it 
> available for free with no restrictions.
> I'd appreciate it if you let me know if you use it (or parts 
> of it) in any other published projects, and if so, due credit 
> and possibly a link back to my site would be nice...
> Regards,
> Dave
> --
> dave04a (at)    Dave Dunfield
> dunfield (dot)  Firmware development services & tools: 
> com             Collector of vintage computing equipment:

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