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

[Karel Kulhavy <clock@xxxxxxxxxxxxx>]

On Wed, Nov 01, 2006 at 10:58:57PM +0000, Michael Sokolov wrote:
> 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.

When the ISP detects this, he can change the standard and then you have
to do the work once more again. Or he puts "only original modem from the
ISP is allowed" into the contract.

Or what if the ISP starts to telling you what you can do and what you can't?
For example, my ISP Cablecom Switzerland says in the contract:
1) they don't guarantee freedom from failures and faults (my modem hangs
every couple of days)
2) you are not supposed to load the link 100% from 14pm to the midnight,
especially by downloading thinigs from p2p, if you do they can cut you off or
limit your rate
3) the rate I pay for is maximum rate, there is no minimum rate
4) The downlink is designated as 4Mbps but it runs 2.2Mbps. The uplink is
something horribly slow (it's assymetric). Which pisses me every time I upload
photographs and compiled PDF's, postscripts and PNG's on the Ronja website.

What is more reliably is getting rid of the abominable ISP and taking the whole
infrastructure into your hands. All you need is my device called Ronja
http://ronja.twibright.com which communicates 10Mbps full duplex over 1.4km
in air with direct visibility using visible or infrared light. Then:

1) Freedom from failures and faults is guaranteed except fog, if a fault comes
all you need is go to your roof and fix what you did wrong, or send a bugreport
to the Ronja mailing list.
2) you are free to load the link 100% 24/7, it doesn't matter, you
don't even see the 100% load on round-trip or web or ssh latency
3) You don't pay any monthly fee. You pay once for the components, the rate is
guaranteed to be 10Mbps +/-200ppm.
4) The link is symmetric, full duplex

Of course you don't get an Internet connection with this, but if you find
more neightbour of friends you can make a LAN and then connect with some
professional-grade connection.

> 
> 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

No. That puts up in front of a choice - either do it with FPGA, or bypass
it somewhere deeper (Ronja).

> 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?

Do something else instead :)

CL<
> Practical sensible solutions only please.
> 
> MS
> 
> 
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