[LMH] Ooh, look! List traffic!

[Robert Swindells]

Dan Moniz wrote:
>On Thursday, March 04, 2004 7:01 PM +0000 Robert Swindells
><rjs@fdy2.demon.co.uk> wrote:

>> Nyef wrote:
>> > On Thu, Mar 04, 2004 at 10:18:20AM -0500, Nyef wrote:
>> >>
>> >> Yes, it's in Lisp. The old (late last year) source tarball is up in
>> >> the same directory as all the screenshots (
>> >> http://www.dridus.com/~nyef/lispm/nevermore/ ), and I'm doing some
>> >> cleanup on the current sources in preparation for releasing them at
>> >> some point in the next day or so.
>>
>> > Fitting action to words, the new version is up as
>> > http://www.dridus.com/~nyef/lispm/nevermore/nevermore-9e0304.tgz
>>
>> > I am uncertain as to if I will be continuing with this codebase.
>> > The speed has reached the point of untenability.
>>
>> I was only half joking about translating it to VHDL.
>>
>> Just having done the analysis of what the microarchitecture needs to
>> do might be useful in the long run.
>>
>> The whole CPU would fit into a $15 FPGA using current technology, add
>> a couple of 16bit SDRAMs and some boot flash and you have a 10x faster
>> microExplorer.

>Which is an interesting point. I wonder how hard it would be to write
>the emulator (or CPU) in Verilog (being somewhat higher-level and
>easier to cope with than VHDL, at least for this task). I assume
>"hard", and that would be an understatement. But possibly worthwhile.

It seems to be a pretty standard student project right now to design
a CPU. Check out <http://www.opencores.org> as well.

I don't think VHDL is too hard or too low level to be useful.

>Of course, there's the longer term problem of getting a monitor and
>input devices to talk to it, which would be painful, and disks, file
>systems, a running install, oh my!

>Probably, now that I think about it, an FPGA-based Explorer processor
>on a PCI card, with some interface glue would be the way to go.

I wrote "microExplorer" on purpose.

>If someone is willing to buy me a simple Xilinx setup (usable FPGA for
>this purpose, test-board, Verilog compiler, etc.), I'll take a crack
>at it. I won't hold my breath, but this equipment has come down in
>price. I think the FPGA we'd want/need is more expensive than the one
>included in their $70 - $100 starter kit.

The free version of Xilinx ISE will target a big enough Spartan 3.

The older PCI card that I'm using at work sells for $200.

Robert Swindells