[Coco] COCO FPGA

[Mark McDougall]

On 23/12/2011 5:19 AM, Joel Ewy wrote:

> and Mark McDougall has implemented a CoCo
> 1/2 on an FPGA board, but I'm not aware of either of these having released
> code, or being available in any other form yet.

Technically, my Coco1/2 is/has always been available on my project site in 
the source repository, which is constantly WIP and occasionally broken.

I did put together a 'manual' of sorts but never officially released 
anything because I wanted to add a few last features (and had a bug with the 
'MPI') and got side-tracked by Real Life and other projects. Like Coco3FPGA, 
the MPI is just banked flash memory, although the idea was to expand it to 
16 slots.

It runs on the Altera DE1 but is not overly useful to anyone (yet); 
certainly not as a general Coco 1/2 replacement. It uses an unmodified 
HDBDOS to read from SD card, but there's no write access (yet). Also runs on 
proprietary hardware with CF, which does have read/write access. 
Additionally, I have a WD1793 implementation running on the TRS-80 Model 
I/III implementation (whose back-end could interface to anything in theory) 
that could be adapted for the Coco; I just never got around to it.

I and a few friends had big plans for a Coco1/2/3 FPGA implementation on 
real hardware that would (also) be a drop-in replacement of the Coco3 
motherboard, with of course expansion slot and some pretty neat features. I 
guess you could call it our version of Coco4. It was the reason I was 
working on my Coco1/2, and we had also started our own 6809 core. We had 
mostly finished the schematics.

One friend in particular was driving the project but, sadly, passed away due 
to illness a few months ago just shy of his 40th birthday. FTR he was a 
_very_ capable hardware engineer, passionate about the Coco, a big fan of 
Steve Bjork, and long time lurker on this mailing list.

My colleague & I are still interested in developing some sort of FPGA-based 
hardware, though whether that form-factor will (initially) be suitable for a 
Coco replacement is another matter. We also have about a dozen projects on 
our to-do list, all of which we've started in one form or another; not sure 
where the Coco fits in now without our mate egging us on. :(

If I didn't have to work, we'd see a 'Coco4' sooner rather than later. But 
alas, I never seem to have enough time, and it's about to get even worse as 
our 1st child is due next year. Maybe if I win the lottery...

Regards,

-- 
|              Mark McDougall                | "Electrical Engineers do it
|  <http://members.iinet.net.au/~msmcdoug>   |   with less resistance!"