[Coco] altera DE1 board

Mark McDougall msmcdoug at iinet.net.au
Tue Oct 19 02:30:56 EDT 2010

On 19/10/2010 4:06 PM, Frank Pittel wrote:

> After a lot of swearing and nashing of teeth I managed to get the
> coco3fpga_dw.sof file loaded onto the board. It even displays "CoCo" on
> the 7-segment displays. Unfortunately all I get on the monitor is a bunch
> of gibberish and it doesn't respond to the keyboard at all. I don't know
> what to make of the stuff in the Software_101.zip file though. While
> poking around on the forume section of the yahoo group I noticed mention
> about installing coco roms/rom images. Is that true and if so where would
> I get such things and how would I "install" them?

As for your frustration: you need to keep in mind that the DE1 is a 
general-purpose FPGA development kit, and not a product designed 
specifically for Coco3FPGA. So there's a bit of ramp-up time required in 
understanding a bit about what you have in front of you, and how to use it, 
even before you start playing with Cocos...

Check out this thread, you're not the first...

It should at least outline the steps you need, although perhaps not enough 
to hold your hand through the process.

Some background technical information.

FPGAs do not (generally) retain their programming after power-down. So most 
designs incorporate an "FPGA configuration device" that will automatically 
configure an FPGA on power-up.

You can program an (Atera) FPGA "temporarily" via the JTAG interface using a 
".SOF" file. This is written directly into the FPGA volatile memory and is 
lost when powered-off. Good for rapid development.

You can also program the configuration device via a ".POF" file. It's pretty 
much just the SOF file but in a different format (usually when you build an 
FPGA project, you ask it to produce both a SOF & POF at the same time). Once 
you've programmed the configuration device, this image will be automatically 
loaded into the FPGA on each power-up.

I can't recall what is programmed into the configuration device on the DE1 
when shipped, but I tend to keep a copy of the DE1 control firmware that was 
shipped on the CD.

Back to Coco3:

There is not enough internal memory in the FPGA on the DE1 to store all the 
ROM images. So Gary has elected to store the COCO3 BASIC ROM in external 
flash memory (at address 0) on the DE1. So the first task is to program the 
flash with this image. You should find adequate instructions to do this in 
your DE1 documentation.

Note that this is a "do-once" process and you shouldn't have to do it ever 
again, unless you use the DE1 for something else that requires the flash memory.

Once that's done, try re-configuring with the SOF.

The Software_101.zip file contains server.exe, which is the (Coco3FPGA) DW 
server that emulates Coco floppy drives on your PC.


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

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