[Oberon] Cheap chinese FPGA board - is it usable for PO?

[Paul Reed]

Hi Bernhard,

> [Cheap board with] Anlogic E[G]4S20 FPGA... Would it be usable for 
> Project Oberon?

Great suggestion, but although at the high level the specs seem amply 
sufficient, please be aware that it is a very considerable effort even 
for specialists to port an FPGA project of any reasonable size from one 
type/technology/manufacturer to another - and that's when the 
documentation is good.

In general it's pretty hard to amortise the significant cost of such an 
effort over just a reduced board price, even at very high quantity; and 
especially so in this case, for a number of reasons which become 
apparent when you start doing deeper research on this particular FPGA.

The chip is unusual for an FPGA in that the useful memory is synchronous 
dynamic RAM bonded onto the programmable logic inside the physical 
package, thereby saving I/O pins which would otherwise be used to 
interface to external memory; but again, it's DRAM, which is a lot 
harder to interface to than the fast asynchronous static RAM in the 
Project Oberon 2013 edition reference design.

I'd be happy to discuss it further but I can't help thinking that any 
effort someone wanted to spend would be better utilised in almost any 
other direction... :)

Cheers,
Paul