[Coco] The Tri-Annual CoCo 4 Thread

[Nick Marentes]

On 14/02/2014 7:08 AM, Steve wrote:
> Nick, I looked up the part on line there is only 119,808 bits of ram 
> on the chip. You will need more that 1,000,00 bits for the 128K of ram 
> on the CoCo 3. Chips with that size of ram run $250 and up.
>

I was only using this board as an example. We'd have to obviously pick 
such a board with the appropriate version of FPGA.

> You could use this line of FPGA if you willing to hook up ram to it.

Yes. I notice the DE1 board has a separate 8Mb RAM.

>
> What if design a board that holds the FPGA, RAM and the other 
> interfaces (ports) to plug in CoCo equipment and have it fit a CoCo 
> case.  The you would have a CoCo replacement.
>
> But that's a lot of work for only 200 units.
>

Yes. That's why I thought that being able to use an off the shelf FPGA 
core board would take away some of the burden. It means that we'd only 
need an I/O board developed which could use easier/lower cost parts.

It has the added bonus of the avbility to upgrade the FPGA core board to 
a newer moire powerful version later.

I'm looking at ways to ease the development cycle to make the chance of 
a CoCo4 more realistic. I like the DE1 board so far but we need a lower 
cost version to attract people who are sitting on the fence about 
whether to jump in.

I'm still new to this FPGA stuff but I can see the potential.

Nick