7 Aug
2001
7 Aug
'01
2:39 p.m.
On Tue, 7 Aug 2001, Tony Duell wrote:
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
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. 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.
[...]
Peter Wallace
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