[Coco] Mark McDougall's CoCo 1/2 FPGA Project

[Mark McDougall]

On 15/11/2017 1:02 AM, Carlos Camacho wrote:

> An email to Mark came back undelivered. I'm trying to reach him via
> Facebook. Maybe he is on this list?

I am indeed!

Which email did you use. I think it should have reached me, unless the 
spam filter got hold of it.

> Looks like PACE used a Altium NanoBoard. I 'think' that used a Cyclone 1
> chip? I was thinking about a bunch of EP2C5T144C8N mini board FPGAs I
> bought to run Grant Searle's various MultiComp (i.e. 6809 version). These
> FPGAs are super cheap on eBay. If the code for Mark's project became
> available, maybe the VHDL code could be ported to the EP2C5T144C8N?

PACE did indeed start with the Altium Nanoboard, but evolved as I (and 
others) acquired more powerful targets. There's 'support' for quite a 
few platforms in there, although typically not every platform (emulated 
system) has been ported to all the supported targets. The main targets 
are DE1 & DE2, plus a few proprietary boards I have.

Bear in mind that the PACE 'framework' is exactly that; a framework 
intended to facilitate both easier addition of new platforms (emulated 
systems) and new targets (hardware). Thus there's a lot of 'baggage' 
that goes with each emulation; you can't just pick out a few files in 
one directory to build a single system. Much like MAME, for example. And 
all this was 'experimental' at best.

Having said that, the Coco1/2 emulation is fairly complete. On a system 
with CF, for example, it's perfectly functional for an end-user. However 
on a system with SD (not CF) the controller is read-only so you can't 
write to the SD card, which limits its use. I'm sure it wouldn't take 
much work now to add write support for SD... I just never got around to 
it. The idea there was to use a back-end module to have the SD 'emulate' 
an IDE/CF device, so that the project would work on both IDE/CF and SD 
systems with very little change.

I'm not 100% sure but if the EP2C5 board is the one I think it is, then 
I actually have a couple that I bought for another project. From memory 
though, there's no RAM on there so I don't think you could run the Coco 
emulation... and perhaps not even enough on-chip memory for the Coco 
ROMS?!? I'd have to check.

Can you send me a link to the EP2C5 boards you bought?

The PACE code was freely available for many years but I removed public 
access only because I wanted to use the (same) SVN repository for 
non-public projects. I don't have a problem with providing an archive of 
it to anyone that is interested.

I haven't touched FPGAs much in the last few years as my day job moved 
more towards software than FPGA work and I now have a young family which 
makes it difficult to spend large blocks of time on my own projects. 
Having said that though, I've recently been involved on the periphery of 
a few other FPGA emulation projects and have just started - literally 
this week - to play around with PACE again.

I've still got other projects I need to finish first (eg. Asteroids for 
Coco3) but I do plan to fiddle with a few FPGA projects, mainly on the 
DE1, in the near future.

Regards,

-- 
Mark McDougall
<http://retroports.blogspot.com.au>