Re: gEDA-user: Re: Pointer to 3d CAD?

[msokolov@xxxxxxxxxxxxxxx (Michael Sokolov)]

Steve Meier <smeier@xxxxxxxxxxxxxxxxxxx> wrote:

> Sure why not here is a link to an individual who built a replica of the
> Apollo Guidance System, using discrete components and wire wrap, in his
> basement.

Of course a discrete logic wire-wrapped computer is cool.  There is no
question on that one.  But there is also a place for FPGAs.  Yes, it
sucks that they require proprietary software.  Unfortunately we don't
have the manpower and firepower to annihilate all police and national
guard etc. and seize the CEOs of Altera and Xilinx, connect variacs to
them and slowly ramp up the voltage until they release full specs for
their chips.  So we can't open-source that part yet.  But we can still
use FPGAs in the meantime to help open-source other things, even if not
the FPGA itself.

As a specific example, right now I'm working on open-sourcing the SDSL
Internet connection technology.  See the project home page I've pointed
to earlier for the gory details.  The basic idea is to get rid of the
abominable closed source "modem" provided by the ISP and to replace it
with an Open Source Hardware device that connects directly to the copper
pair and talks the SDSL electrical signal format in open source.

If the SDSL line uses ATM as all newer DSLAMs do, connecting to it
requires an ATM TC-PHY (implementation of I.432.1) and possibly also a
custom framer.  Now let's be practical here -- do you think that an
SSI/MSI implementation of those components would make a practically
usable DSL modem, one that can readily replace the one provided by the
ISP?  An FPGA implementation easily can, however.  Replacing the ISP-
provided box with an open source implementation that uses an FPGA won't
increase the number of closed source components in your house because
the ISP-provided SDSL modem has one too if it's an ATM-based flavor of
SDSL.  But the other components of the "modem", i.e., the top level
architecture, the microprocessor firmware, all layer 2 and higher stuff,
will change from closed to open source.  Isn't that a worthy goal?
We can open-source SDSL using an Altera FPGA now (the exact same FPGA
used in the current Covad-provided router), while open-sourcing the FPGA
itself will have to wait until we can gather enough manpower and
firepower to annihilate the PD in whatever city harbors the Altera CEO
and hook electrodes to the bastard.

Another reason why an FPGA saves the day is that there are umpteen
gazillion different flavors of SDSL -- as many as there are DSLAM
vendors, each making their own CPE "modem" with Yet Another proprietary
router OS to fight with.  My open SDSL connectivity project seeks to
replace them all with a single open source hardware platform that can
handle all flavors.  How would you propose doing that without an FPGA?
Practical sensible solutions only please.

MS


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