[Oberon] Digilent Spartan 3 Board, and ORP and ORG are back

[Paul Reed]

Dear all who have enquired,

(Some who emailed me directly, I've BCC'd - please try to ask on the list
if you can - thanks)

> On Tue, Mar 4, 2014 at 4:10 AM, Paul Reed <paulreed at paddedcell.com> wrote:
>> The simplicity of the board means that it is 'just enough' (with the
>> addition of a small and simple do-it-yourself-daughterboard for the
>> SD-card hard disk, mouse and wireless network module) to implement the
>> Oberon system in a nice resource-constrained and understandable way.
>> Porting the simplicity, rather than the system, to another board would
>> be
>> quite hard.
>
> With all of the chatter about ports, I've been randomly Googling the
> Spartan 3-like boards, and it seems you're right, there's just not
> anything quite in the same category.
>
> But, out of curiosity, is there no facility to use a standard PS/2 Y
> cable to add the mouse?

The PS/2 connector on the Spartan 3 Board is only wired for one PS/2
interface, see the schematic.


>> The real killer feature about the Spartan 3 board is the 1MByte
>> (2x256Kx16) of extremely fast (10nS) static RAM (as in, real good
>> old-fashioned SRAM, not pseudo-SRAM for example!).  I haven't found a
>> board which provides sustained, completely random-access cycles anywhere
>> near as fast; anything else I have seen would imply a memory interface
>> which would dwarf the rest of the whole design in its complexity.  Of
>> course, I'd be delighted to be proved wrong about this. :)
>
> Is that a design problem that would eventually have to be overcome anyway?

What, that it's not complicated enough?  I don't see that as a design
problem, but many commercial operations would :)  Seriously though, I'm
not sure I understand your question (sorry!).


> I was looking at the older Altera boards, something like the DE0 with
> no SRAM, does a design like that make it easier or harder, or would
> something like the DE1 be a) more typical and b) the standard design
> challenge?
>
> -Jack
>
> --
> Oberon at lists.inf.ethz.ch mailing list for ETH Oberon and related systems
> https://lists.inf.ethz.ch/mailman/listinfo/oberon

The DE0 looks quite nice since it already has an SD-Card slot, which is
most of the pain about a daughterboard; but still, no SRAM (see above). 
However, it is unusual in that it is quite a simple board, compared with,
say the Nexys 3 and others, which only purport to be simple...

I know that simplicity is often used as a relative term, but if something
has to be explained completely and in detail then simple takes on an
absolute meaning.  That's the value in Project Oberon, from understanding
it completely - but Chris Burrows expressed it much better.

On another subject please note that ORG.Mod.txt and ORP.Mod.txt are back
on Prof. Wirth's site, sincere apologies for any inconvenience caused by
the short outage.

Paul