Build your own 6809 based computer!

[tjewell]

Hi all - this is well beyond my technical skills, but I stumbled across this recently and thought it might be of interest to everyone here:

https://sites.google.com/site/theuniver ... ard-design

I'd be fascinated to see one in action!

Tony.

[Rink]

Hmmm... mixed opinions about those docs.

But designing your own 8-bit computer system from scratch isn't that hard - just a bit time consuming and a little costly if you're getting PCBs made in China every time you want to try something or hit the next "stage" in your build. The way I see it: if you're going to build one, you might as well build one that is completely your design - with all the features that you want and none of the features you don't, rather than a fairly generic system.

I'm building a Z80-based machine at the minute as it happens. It's fun. The guys who designed the machines back in the day with much less reference work and project reports etc. to learn from must have been bloody smart. But nowadays, every question you might have during your design and build is dealt with somewhere on the internet.

[johnha]

Although new to the forum, I have a long standing interest in 6809 based processors (whilst at uni I used my Dragon to test run 6800 machine code and my final year project was image processing Landsat images in assembler on a dedicated 6809 system). In fact I do have a 6809 'development board', bought from CirKit way back when (about £80 at the time). It has the 6809, space for a ROM chip, a couple of RAM chips (2 or 4K) and an ACIA/PIA IIRC. I didn't get very far with it as I didn't have access to an EPROM programmer.

If doing something similar today, I'd look at wire-wrapping instead of PCBs at least until you've got it running (note: I've never tried wire-wrapping data & address busses!). I also have had thoughts about doing something with a Z80 or FPGA of some sort.

John.

[jedie]

has anyone tried it?

[tormod]

I think I looked up the document in the original post once. I did not get totally convinced that the author actually had made one himself. There was a lot of detail on trivial things, and no comments on the difficult parts...

DIY projects sometimes come up in the CoCo mailing list. See for instance the link in this post http://five.pairlist.net/pipermail/coco ... 70837.html where Kip tells about his home-made 6809 computers.

[jedie]

nice.

There was a link to: http://searle.hostei.com/grant/6809/Simple6809.html
Very cool! ...if i had more time...