[Coco] Terasic DE-1

[Mark McDougall]

On 15/11/2018 9:04 AM, Dave Philipsen wrote:

> Does the DE10 Nano have flash memory to hold the contents of the CoCo 
> ROMs?  Does it have an audio codec, DRAM, SRAM, etc?  I'm not saying 
> it's completely impossible but by the time you get through trying to 
> make CoCo3FPGA work on that device it may not really be considered 
> CoCo3FPGA anymore. And you'd probably be just as well off starting from 
> scratch...

Not at all. I've ported projects across different platforms with/without 
external memory and there's often no need to modify the project itself.

What I've done is create a "target wrapper" around the project that, on 
relevant/suitable target hardware, emulates flash/SRAM within the fabric 
of the FPGA. Because it's external to the project, there's no need to 
modify it as it still "sees" external memory devices.

> I have implemented CoCo3FPGA on a non-Terasic board that had quite a few 
> similarities to the DE-1 and even that implementation falls short of 
> having all of the features of a real CoCo3FPGA.

Of course every target has its own strengths and weaknesses and to be 
fair, Coco3FPGA has been designed primarily around the DE1 (plus 
Zippster's add-on board) so naturally it's going to have the most 
features out-of-the-box.

By that same token, other platforms may have superior hardware features 
that aren't readily utilised by the Coco3FPGA project. eg. I have 
hardware with an FPGA large enough to fit a dynamic video scaler and 
HDMI output, USB host and device ports, GB of DDR3 SDRAM, but no SD/CF 
card...

Regards,

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