Why so few garage processors? (was Re: Squeak History / Tiny
Machines)
Andrew Berg
andrew_c_berg at yahoo.com
Wed Mar 19 19:40:31 UTC 2003
On Wed, 19 Mar 2003 11:20:07 -0600, Jimmie Houchin <jhouchin at texoma.net>
wrote:
> I don't necessarily understand what you wrote above. :)
>
> However, I would be willing to buy a board that I could build a
> Screamin'Squeak machine with. My primary desire would be good performance
> and ability to use commodity parts, ie: memory, sound, graphics, etc. And
> a reasonable price. Nothing above is a problem.
Well, now there is a bit of an interesting problem. Building a memory
controller to talk to "commodity" DDR SDRAM DIMMs is a non-trivial task,
and probably one that would tax the number of pins available from even a
very expensive XILINX FPGA. Stepping back from that a bit, we have to
support video, so an AGP port. That is pretty hard, and (alone) would tax
the pincount of a midrange XILINX FPGA like Ned was talking about. Maybe
we'll do PCI instead, but now we're only at the fringes of "commodity", and
still a non-trivial thing to make work. Now, we don't have a HD interface,
so we'll have to add one, we don't have keyboard/mouse ports, so we'll have
to add a USB card, we don't have . . . (long list later:) so we'll have to
add one. Unfortunately, compared with version 59 of our washing machine
computer, we're way over on cost.
>
> With that I think you could have a winner for people who think outside of
> the box.
Let's really think outside the box for a minute: A processor in a XILINX
with a SRAM memory controller (simple), some flash (simple) and a 100Mbit
ethernet adapter (not too bad). The flash contains just enough to make it
boot from a tftp server: Fetch down a HAL/VM, and then a Squeak image.
For video/mouse/keyboard/?sound?, let's throw an old wintel box at it with
Linux and X via the network. 8MB of SRAM is pretty affordable these days,
64 not unreasonable.
For v.2, we could perhaps add USB or FireWire and SATA for HD support.
What could such a machine do? Well, since the single most important device
for a computer nowadays is the network, it could do rather a lot. However,
without a local HD, we'd have to write SMB or NFS into Squeak in order for
any file-related things to work, but that should be at least minimally
doable. The existing *NIX VM handles X connections, so we'd have to write
an X client library into either the VM or Squeak, which is hard, but
doable. To just get key/mouse events into and bitblt out of the image
seems fairly straightforward.
Really, though, you are not going to beat Intel on performance (at least I
don't think so). A far easier path to making things fast will probably be
to make the JIT compiler better, and to profile/optimize Morphic some. Or
go back to MVC. ;) If you are just looking for different, eh, what was
the point again?
>
> Come on Squeak Machines Inc. :)
>
> Jimmie Houchin
>
>
Of course having said that, I should probably admit that I have a XILINX
prototype board, XILINX logic tools, and the start of a similar (LISP
oriented) project sitting in a cabinet in my basement right now. What I
really want is a PCI board that has a big XILINX chip on it, all pre-
fabbed, so that I can program it to be a co-processor for my Intel box, and
then I can use my Pentium to its fullest potential: I/O subprocessor. :)
As yet, I have not seen that board for sale. :(
-andrew
--
andrew_c_berg at yahoo.com
More information about the Squeak-dev
mailing list
|