Now *this* is cool

From: Peter C. Wallace <pcw_at_mesanet.com>
Date: Tue Aug 7 14:39:36 2001

On Tue, 7 Aug 2001, Tony Duell wrote:

> > > That's right. For each part, there will come a time when there are no
> > > more original, functioning instances. Our ability to continue the
> > > tradition will then lie in our ability to put something else in their
> > > place.
> >
> > Right, Jeff.
> >
> > And this was a conversation I meant to finish with Tony Duell. I made
> > a remark about the speed I was seeing in a particular simulator of old
> > iron as run on a 233MHz Pentium-1 PC. Tony remarked that he didn't have
> > a machine of the host class (the Pentium-1 PC), so the simulator was
> > therefore not available to him, but that it didn't matter much to him
> > because he prefers the *real* original iron anyway.
>
> FWIW, FPGA-based re-implementations of classic computers don't satisfy my
> interests either. For 2 main rasons :
>
> 1) I don't have any machine (read : lusedoze box) that will run the
> development tools, so I can't get in there and 'tinker'

You dont need too much though, free web accessable tools are available
from Xilinx (webfitter) and probably others,

>
> 2) You can't clip a logic analyser onto the internal signals of an
> FPGA... Remember I think of computers in terms of gates and flip-flops...

Sure you can, its easy to build the logic probe into the FPGA and access
it through some free I/O pins...

>
> I am not at all convinced that there will be a time when it will be
> impossible to keep something like a PDP11 running, either. All the chips
> in something like an 11/10 or 11/45 are documented. You could, if you had
> to, re-implement a single chip in an FPGA. Sure it would be a waste of
> FPGA, but if the time came when you couldn't get (say) a 74S181, and you
> needed one, that would be a way of keeping the machine operational.
>
> [...]
>
> > Now, the FPGA route is even better than a simulator, of course, because
>
> As I menitoned above, to me they're much the same in that they don't
> provide what I am interested in...
>
> -tony
>
>

Peter Wallace
Received on Tue Aug 07 2001 - 14:39:36 BST