[SI-LIST] Re: AC Coupled Signals
- From: steve weir <weirsi@xxxxxxxxxx>
- To: Jory McKinley <jory_mckinley@xxxxxxxxx>
- Date: Tue, 25 Sep 2007 13:34:37 -0700
Jory, I think this is good example of where intuitively appealing
misconceptions can seduce one into translating correlation into
causation. If you have more ringing in one case than another, it means
that you have set up a resonance that is more severe in the one case.
This can easily happen as a result of any number of things going on:
suboptimal silicon to package launch, suboptimal IC to PCB, via stubs,
connector transitions, etc, etc.
The very simple test is to take a VNA, a couple of sections of coax and
a DC block. Move the DC block between the transmit end, the junction of
the two cables, and the receiver and look at the behavior of that net
channel. With good coax and connectors the channel performance will
change almost immeasureably. Now go and add a coax T on one side of the
DC block. Move that whole thing around as a unit and again the channel
performance remains the same. Add a second coax T on the other side of
the DC block from the first, and again move the whole thing around. The
results will still remain uniform. Now if you go and move one of those
T's someplace else, then the pesky mole you're trying to whack moves and
the resonance will pop up somewhere else. The bottom line is that it's
resonance that we need to fight and resonance doesn't know left from right.
Regards,
Steve.
Jory McKinley wrote:
> To add to this, I will ask for release of lab data that I took that
> shows RX_EYE clearly improves as the AC cap/term location is moved
> closer to the RX. The data indicates that even though overall channel
> loss may not be affected, the 50ps edge rates we are sending through
> the channel are affected (in terms of time domain ringing) by the AC
> cap/term placement. This kind of feels right.
> -Jory
>
>
> ----- Original Message ----
> From: steve weir <weirsi@xxxxxxxxxx>
> To: Stephen Zinck <signalintegrity@xxxxxxxxxxx>
> Cc: Scott McMorrow <scott@xxxxxxxxxxxxx>; jory_mckinley@xxxxxxxxx;
> leeritchey@xxxxxxxxxxxxx; npatel@xxxxxxxxxx; si-list@xxxxxxxxxxxxx
> Sent: Tuesday, September 25, 2007 12:52:41 PM
> Subject: Re: [SI-LIST] Re: AC Coupled Signals
>
> Steve, as far as I know where we have agreement that capacitor location
> can only affect performance where the combined capacitor and mount
> presents a discontinuity and that discontinuity is located such that it
> forms a resonant structure with another discontinuity in the channel. I
> fail to see where we have moved any closer to supporting your premise
> that locating a greater proportion of fixed loss before the capacitor
> changes end to end loss than placing that same fixed loss behind it.
>
> As for lab measurements, we have these as we have characterized many
> links. We also have extensive simulations.
>
> Regards,
>
>
> Steve.
>
> Stephen Zinck wrote:
> > Hi Steve,
> >
> > I understand your point but I actually thought Scott and I were
> > getting close. I guess I still need him to explain his statement:
> > "The only time position matters is in the face of discontinuities."
> > because this runs counter to your assertion.
> >
> > It would be good to have some concrete lab measurement results to back
> > either of our points up. I am sorry I don't have any.
> >
> > We agree on TDR/VNA characteristics...
> >
> > Steve
> >
> > Stephen P. Zinck
> > Interconnect Engineering Inc.
> > P.O. Box 577
> > South Berwick, ME 03908
> > Phone - (207) 384-8280
> > Email - szinck@xxxxxxxxxxxxxxxxxxxxxxxxxxx
> > Web - www.interconnectengineering.com
> <http://www.interconnectengineering.com>
> >
> > ----- Original Message ----- From: "steve weir" <weirsi@xxxxxxxxxx>
> > To: <signalintegrity@xxxxxxxxxxx>
> > Cc: "Scott McMorrow" <scott@xxxxxxxxxxxxx>; <jory_mckinley@xxxxxxxxx>;
> > <leeritchey@xxxxxxxxxxxxx>; <npatel@xxxxxxxxxx>; <si-list@xxxxxxxxxxxxx>
> > Sent: Tuesday, September 25, 2007 12:24 PM
> > Subject: [SI-LIST] Re: AC Coupled Signals
> >
> >
> >> Stephen, OK so when you say "lossy" or "nonlinear" you mean=20
> >> discontinuous. Discontinuities aggravate resonances based on
> >> specific=20
> >> structure material and geometries, in other words the distance on a=20
> >> centimeter or millimeter scale between discontinuities. We have=20
> >> essentially the same opportunities for channel discontinuities at and
> >> in =
> >>
> >> the vicinity of the transmitter as the receiver. So I still do not
> >> see=20
> >> a defensible basis for the offered position: that placing a capacitor
> >> at =
> >>
> >> one end of the line versus the other changes the end to end loss.
> >> What=20
> >> matters is if wherever I place one discontinuity that it sets up a
> >> sharp =
> >>
> >> resonance with another discontinuity. That can happen equally well
> >> at=20
> >> either end of the line.
> >>
> >> If one looks at a channel with only a TDR I might understand the=20
> >> erroneous perception that placing a discontinuity down the line is=20
> >> better than up front. But that is an illusion. TDR resolution
> falls=20
> >> with interconnect distance. This ia a result of the inherent loss
> of=20
> >> the interconnect that shelves bandwidth and hence resolution versus=20
> >> distance for the instrument. This is one of the big limitations of
> a=20
> >> TDR for channel evaluation. A through measurement with a TDT or VNA=20
> >> does not suffer that limitation, give true measure of S21 and so
> >> report=20
> >> the real channel performance. Eric Bogatin spends some time on the=20
> >> issue of bandwidth versus interconnect length in his book.
> >>
> >> Regards,
> >>
> >>
> >> Steve.
> >> Stephen Zinck wrote:
> >>> Scott,
> >>> We may have some nomenclature issues here...=20
> >>>
> >>> When I say "lossy interface to the capacitor" I mean with impedance
> >>> dis=
> >> continuities. So I think we are on a similar page given your statement:
> >>>
> >>> "The only time position matters is in the face of discontinuities."
> >>>
> >>> Again, most often, my role is to simulate the customers system at
> >>> the 1=
> >> 1th hour. I don't recommend this, I just work within the customer's
> >> needs=
> >> /requirements. I make real world recommendations from simulation
> >> results =
> >> for designs where these discontinuities you mention are a fact of
> >> life. G=
> >> ranted my customers are not doing 5+ Gbit/s designs (right now ;-).
> >>>
> >>> Above these data-rates, all you mention, capacitor transition (pad,
> >>> via=
> >> s, etc) are of the utmost importance. And I would absolutely agree
> >> that t=
> >> he more perfect you make these transitions, the less it matters where
> >> the=
> >> y are placed...
> >>>
> >>> So I do believe AC coupling capacitor position does matter, as you
> >>> stat=
> >> e, for the bulk of the designs occurring these days where component
> >> footp=
> >> rint and via optimization, etc. is NOT occurring...
> >>>
> >>> Steve
> >>>
> >>> Stephen P. Zinck
> >>> Interconnect Engineering Inc.
> >>> P.O. Box 577
> >>> South Berwick, ME 03908
> >>> Phone - (207) 384-8280
> >>> Email - szinck@xxxxxxxxxxxxxxxxxxxxxxxxxxx
> >>> Web - www.interconnectengineering.com
> <http://www.interconnectengineering.com>
> >>>
> >>> ----- Original Message -----=20
> >>> From: Scott McMorrow=20
> >>> To: Stephen Zinck=20
> >>> Cc: jory_mckinley@xxxxxxxxx ; leeritchey@xxxxxxxxxxxxx ;
> >>> npatel@micro=
> >> n.com ; si-list@xxxxxxxxxxxxx=20
> >>> Sent: Tuesday, September 25, 2007 11:08 AM
> >>> Subject: Re: [SI-LIST] Re: AC Coupled Signals
> >>>
> >>>
> >>> Steven,
> >>>
> >>> I would not agree with your following statements.
> >>>
> >>> "I agree in theory with all you state. Assuming a lossless
> >>> interface =
> >> to the capacitor, it shouldn't matter where you place it, given a
> >> purely =
> >> linear system. But the real world is lossy, even when one makes great
> >> 3D =
> >> solved structures. Manufacturing and other tolerances tend to take
> >> the tr=
> >> ek towards perfection to task."
> >>>
> >>> "Would either of you agree that AC coupling capacitor location may
> >>> ma=
> >> tter with a lossy interface to the capacitor?"
> >>>
> >>>
> >>> Insertion loss in a flat impedance linear lossy system will be
> >>> indepe=
> >> ndent of capacitor location. Run the math and see. The only time
> >> positi=
> >> on matters is in the face of discontinuities. In fact, given a low
> >> loss=
> >> interconnect with discontinuities and a high loss interconnect with
> >> disc=
> >> ontinuities, the low loss system, with it's higher Q, will often have
> >> wor=
> >> se behavior.
> >>>
> >>> An improperly designed 0402 capacitor transition for a 50 ohm line
> >>> ca=
> >> n easily exhibit a discontinuity of 35 ohms for 50 ps. If attached
> >> to po=
> >> orly designed via transitions, the discontinuity will be even worse.
> >> Whe=
> >> n this is coupled closely to a high capacitance receiver input, a
> >> high ca=
> >> pacitance transmitter output, a low impedance via stub discontinuity,
> >> or =
> >> a low impedance connector discontinuity, it can form a 1/2 wave
> >> resonant =
> >> circuit. This is most likely the problem you are seeing. =20
> >>>
> >>> If the interconnect has essentially flat impedance, position does
> >>> not=
> >> matter. If the capacitor transition is properly designed, position
> >> does=
> >> not matter. All of the data we have on this is proprietary at this
> >> time=
> >> =2E Our understanding of the physics has been verified by full wave
> >> mode=
> >> ling, simulation and measurement.
> >>>
> >>>
> >>>
> >>> regards,
> >>>
> >>> Scott
> >>>
> >>>
> >>>
> >>> Scott McMorrow
> >>> Teraspeed Consulting Group LLC
> >>> 121 North River Drive
> >>> Narragansett, RI 02882
> >>> (401) 284-1827 Business
> >>> (401) 284-1840 Fax
> >>>
> >>> http://www.teraspeed.com
> >>>
> >>> Teraspeed=AE is the registered service mark of
> >>> Teraspeed Consulting Group LLC
> >>>
> >>>
> >>> Stephen Zinck wrote:=20
> >>> Hi Scott and Steve,
> >>>
> >>> To answer both of your questions, it is the resulting Hspice
> >>> (with =
> >> S-parameters) differential eye patterns, as viewed at the receiver
> >> die, t=
> >> hat were used to make a comparison of source versus destination AC
> >> coupli=
> >> ng capacitor locations. The system was excited with a string of ones,
> >> fol=
> >> lowed by a single zero, followed by a string of ones.=20
> >>>
> >>> I have not specifically designed a test board that varies the AC
> >>> co=
> >> upling capacitor location along a trace.
> >>>
> >>> I understand the "shades of gray" here and agree that one can't
> >>> mak=
> >> e a "rule of thumb" generalization in our line of work these days.=20
> >>>
> >>> I agree in theory with all you state. Assuming a lossless
> >>> interface=
> >> to the capacitor, it shouldn't matter where you place it, given a
> >> purely=
> >> linear system. But the real world is lossy, even when one makes great
> >> 3D=
> >> solved structures. Manufacturing and other tolerances tend to take
> >> the t=
> >> rek towards perfection to task.=20
> >>>
> >>> Do either of you have real world measured results, that you
> >>> could s=
> >> hare, that show no marked difference in received signal
> >> characteristics w=
> >> hen the AC coupling capacitor position is varied through a 30 inch
> >> backpl=
> >> ane system (or similar)?
> >>>
> >>> I believe my experience with capacitor location may prove true
> >>> if t=
> >> he capacitor interface is lossy (which is the case). A lot of my
> >> customer=
> >> s are just looking for quick ways to maximize performance using
> >> standard =
> >> component packages and standard layout practices (in the end, I don't
> >> lik=
> >> e to give anything away that is low lying fruit). Most of the time I
> >> am d=
> >> oing my analysis after the board is in layout, where I have limited
> >> abili=
> >> ty to change the design (unless it is really broken). In a perfect
> >> world,=
> >> where I am involved early, the package optimization and layout
> >> structure=
> >> s can be optimized as you state, but only if the margins warrant it
> >> (syst=
> >> em performance issues are expected after initial "what-if"
> >> simulations ha=
> >> ve occurred). The right tool for the right job rules the day...
> >>>
> >>> Would either of you agree that AC coupling capacitor location
> >>> may m=
> >> atter with a lossy interface to the capacitor?
> >>>
> >>> All the best,
> >>> Steve
> >>>
> >>> Stephen P. Zinck
> >>> Interconnect Engineering Inc.
> >>> P.O. Box 577
> >>> South Berwick, ME 03908
> >>> Phone - (207) 384-8280
> >>> Email - szinck@xxxxxxxxxxxxxxxxxxxxxxxxxxx
> >>> Web - www.interconnectengineering.com
> <http://www.interconnectengineering.com>
> >>>
> >>> ----- Original Message -----=20
> >>> From: Scott McMorrow=20
> >>> To: Stephen Zinck=20
> >>> Cc: jory_mckinley@xxxxxxxxx ; leeritchey@xxxxxxxxxxxxx ;
> >>> npatel@m=
> >> icron.com ; si-list@xxxxxxxxxxxxx=20
> >>> Sent: Tuesday, September 25, 2007 9:44 AM
> >>> Subject: Re: [SI-LIST] Re: AC Coupled Signals
> >>>
> >>>
> >>> Stephen
> >>>
> >>> Define "better" and then relate your simulations and
> >>> conclusions =
> >> to linear system theory and measurements. =20
> >>>
> >>> I contend that the only difference an AC coupling capacitor
> >>> can p=
> >> ossibly have due to position in a linear interconnect is a result of
> >> impe=
> >> dance mismatch. I contend that the capacitor will form a 1/2 wave
> >> resona=
> >> nt circuit with other interconnect discontinuities (connectors, vias
> >> stub=
> >> s, packages, Tx die, Rx die ... etc) and that this interaction is
> >> system,=
> >> chip, connector and package design dependent. I contend that it is
> >> this=
> >> 1/2 resonance that can cause differences that can be measured, but
> >> that =
> >> there is no "rule of thumb", since the position and magnitude of
> >> disconti=
> >> nuities are different in every system. In some systems the receiver
> >> cons=
> >> titutes a larger discontinuity than the transmitter. In other
> >> systems th=
> >> is is reversed. In yet other systems, connectors and vias represent
> >> larg=
> >> er discontinuites than do either the transmitters or receivers. It
> >> all "j=
> >> ust depends". To state a specific rule is just plain incorrect.
> >>>
> >>> I contend that once you remove the magic and myths surrounding
> >>> AC=
> >> coupling capacitors, analysis of the 3D structure shows that by
> >> reducing=
> >> the signal path discontinuity through the capacitor, you will
> >> necessaril=
> >> y improve performance. An AC coupling capacitor, with it's
> >> associated vi=
> >> a and pad transition design, can be viewed as a black box which has
> >> inser=
> >> tion loss and return loss, and can be modeled quite well using either
> >> lum=
> >> ped element approximations or (my favorite) S-parameters. As such it
> >> wil=
> >> l cascade in a simulation model just like any other linear element.
> >> If w=
> >> e start with a system with flat 50 ohm impedance from end to end, it
> >> can =
> >> be easily shown that no matter what the position of the capacitor
> >> along t=
> >> he interconnect is, the insertion loss of the system is identical.
> >> It is=
> >> only the return loss, as seen from each end that changes.
> >>>
> >>> I've been designing AC coupling capacitor mounting transitions
> >>> pr=
> >> operly for quite a few years now and have some 0402 designs that keep
> >> S12=
> >> above -0.2 dB up to 7.5 GHz, S12 below -20 dB @ 5 GHz, and below -15
> >> dB =
> >> @ 10 GHz. For all practical purposes, these designs are transparent
> >> and =
> >> may be placed anywhere in an interconnect design where there is
> >> space, si=
> >> nce there is little resonance interaction with other devices and
> >> structur=
> >> es.
> >>>
> >>>
> >>> Scott
> >>>
> >>>
> >>> Scott McMorrow
> >>> Teraspeed Consulting Group LLC
> >>> 121 North River Drive
> >>> Narragansett, RI 02882
> >>> (401) 284-1827 Business
> >>> (401) 284-1840 Fax
> >>>
> >>> http://www.teraspeed.com
> >>>
> >>> Teraspeed=AE is the registered service mark of
> >>> Teraspeed Consulting Group LLC
> >>> =20
> >>>
> >>> Stephen Zinck wrote:=20
> >>> Hi Scott,
> >>>
> >>> My simulations show that the capacitor is best placed at the
> >>> re=
> >> ceiver end of the transmission-line. Do you disagree? If so, why?
> >>>
> >>> Steve
> >>>
> >>> Stephen P. Zinck
> >>> Interconnect Engineering Inc.
> >>> P.O. Box 577
> >>> South Berwick, ME 03908
> >>> Phone - (207) 384-8280
> >>> Email - szinck@xxxxxxxxxxxxxxxxxxxxxxxxxxx
> >>> Web - www.interconnectengineering.com
> <http://www.interconnectengineering.com>
> >>>
> >>> ----- Original Message -----=20
> >>> From: Scott McMorrow=20
> >>> To: signalintegrity@xxxxxxxxxxx=20
> >>> Cc: jory_mckinley@xxxxxxxxx ; leeritchey@xxxxxxxxxxxxx ;
> >>> npat=
> >> el@xxxxxxxxxx ; si-list@xxxxxxxxxxxxx=20
> >>> Sent: Tuesday, September 25, 2007 8:30 AM
> >>> Subject: Re: [SI-LIST] Re: AC Coupled Signals
> >>>
> >>>
> >>> Stephen,
> >>>
> >>> I'm sorry, this is a linear system. Except for possible
> >>> reso=
> >> nances that are created by discontinuities and modal conversion
> >> (which ha=
> >> ve absolutely zero to do with signal rise time), there is no
> >> difference i=
> >> n the attenuation of a capacitor placed at the Tx as opposed at the
> >> Rx. =
> >> W.R.T. the receiver, if it is "lost in the rise-time degradation of
> >> the =
> >> system", it will be lost wherever it is placed.
> >>>
> >>>
> >>>
> >>> Scott McMorrow
> >>> Teraspeed Consulting Group LLC
> >>> 121 North River Drive
> >>> Narragansett, RI 02882
> >>> (401) 284-1827 Business
> >>> (401) 284-1840 Fax
> >>>
> >>> http://www.teraspeed.com
> >>>
> >>> Teraspeed=AE is the registered service mark of
> >>> Teraspeed Consulting Group LLC
> >>> =20
> >>>
> >>> Stephen Zinck wrote:=20
> >>> Hi Jory,
> >>>
> >>> I have simulated this at length and concur with your experience that
> >>> th=
> >> e=20
> >>> capacitor is best placed at the receiver...
> >>>
> >>> In effect, the attenuation associated with the capacitor placement
> >>> at t=
> >> he=20
> >>> receiver (parasitics/pads/vias) is lost in the rise-time degradation
> >>> of=
> >> the=20
> >>> system.
> >>> The classic "don't break it until you have to" rule is applicable...
> >>> OK=
> >> this=20
> >>> is my rule... :-)
> >>>
> >>> All the best,
> >>> Steve
> >>>
> >>> Stephen P. Zinck
> >>> Interconnect Engineering Inc.
> >>> P.O. Box 577
> >>> South Berwick, ME 03908
> >>> Phone - (207) 384-8280
> >>> Email - szinck@xxxxxxxxxxxxxxxxxxxxxxxxxxx
> >>> Web - www.interconnectengineering.com
> <http://www.interconnectengineering.com>
> >>>
> >>> ----- Original Message -----=20
> >>> From: "Jory McKinley" <jory_mckinley@xxxxxxxxx>
> >>> To: <leeritchey@xxxxxxxxxxxxx>; <npatel@xxxxxxxxxx>;
> >>> <si-list@freelists=
> >> =2Eorg>
> >>> Sent: Monday, September 24, 2007 5:31 PM
> >>> Subject: [SI-LIST] Re: AC Coupled Signals
> >>>
> >>>
> >>> I will elaborate a bit on what I have seen. I have measured (time
> >>> dom=
> >> ain)=20
> >>> in the lab some effects that appears to be location specific in the=20
> >>> placement of the AC coupling caps at the rcvr. Now this may be due
> >>> in =
> >> part=20
> >>> to the fact that I am using 50-ohm resistor termination in each lead
> >>> as=
> >> =20
> >>> well and the combination (cap plus rcvr reflection) is giving some=20
> >>> imbalance depending on distance. The best rcvr eye that I am seeing
> >>> is=
> >> =20
> >>> when I can move the AC/term as close to the rcvr as I can. By the
> >>> way =
> >>
> >>> these are 5Gb/s signals.
> >>> If I have time I will try and isolate what I am seeing and even
> >>> simulat=
> >> e=20
> >>> it, has anyone else seen or simulated this?
> >>> -Jory
> >>>
> >>> ----- Original Message ----
> >>> From: Lee Ritchey <leeritchey@xxxxxxxxxxxxx>
> >>> To: "npatel@xxxxxxxxxx" <npatel@xxxxxxxxxx>; si-list@xxxxxxxxxxxxx
> >>> Sent: Monday, September 24, 2007 1:06:06 PM
> >>> Subject: [SI-LIST] Re: AC Coupled Signals
> >>>
> >>> Nikil,
> >>>
> >>> I have made measurements on test PCBs and the location is not all that
> >>> important. In identical pairs, one with AC coupling capacitors and
> >>> the=
> >>
> >>> other without, the loss vs. frequency is virtually identical at leas
> >>> ou=
> >> t=20
> >>> to
> >>> 6 GHz. That would be 12 Mb/S.
> >>>
> >>> Lee Ritchey
> >>>
> >>>
> >>> [Original Message]
> >>> From: <npatel@xxxxxxxxxx>
> >>> To: <si-list@xxxxxxxxxxxxx>
> >>> Date: 9/24/2007 10:21:37 AM
> >>> Subject: [SI-LIST] AC Coupled Signals
> >>>
> >>> Hi all,
> >>> In case of AC coupled signals does anyone know of an optimum placement
> >>> for the caps? I mean should they be placed near the source, receiver,
> >>> middle of the transmission line?
> >>> How much difference does it make in the opening of the eye?
> >>> The signals are differential CML running at 3.0Gbps
> >>>
> >>> Thanks,
> >>> Nikhil
> >>>
> >>>
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> _______________________________________________________________________=
> >>>
> >> _____________
> >>> Moody friends. Drama queens. Your life? Nope! - their life, your
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> >> =20
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> >> --=20
> >> Steve Weir
> >> Teraspeed Consulting Group LLC=20
> >> 121 North River Drive=20
> >> Narragansett, RI 02882=20
> >>
> >> California office
> >> (408) 884-3985 Business
> >> (707) 780-1951 Fax
> >>
> >> Main office
> >> (401) 284-1827 Business=20
> >> (401) 284-1840 Fax=20
> >>
> >> Oregon office
> >> (503) 430-1065 Business
> >> (503) 430-1285 Fax
> >>
> >> http://www.teraspeed.com
> >> This e-mail contains proprietary and confidential intellectual
> >> property o=
> >> f Teraspeed Consulting Group LLC
> >>
> -------------------------------------------------------------------------=
>
> >>
> >> -----------------------------
> >> Teraspeed(R) is the registered service mark of Teraspeed Consulting
> >> Group=
> >> LLC
> >>
> >>
> >> ------------------------------------------------------------------
> >> To unsubscribe from si-list:
> >> si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field
> >>
> >> or to administer your membership from a web page, go to:
> >> //www.freelists.org/webpage/si-list
> >>
> >> For help:
> >> si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
> >>
> >>
> >> List technical documents are available at:
> >> http://www.si-list.net
> >>
> >> List archives are viewable at:
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> >> or at our remote archives:
> >> http://groups.yahoo.com/group/si-list/messages
> >> Old (prior to June 6, 2001) list archives are viewable at:
> >> http://www.qsl.net/wb6tpu
> >>
> >>
> >>
> >
> >
> >
> >
>
>
> --
> Steve Weir
> Teraspeed Consulting Group LLC
> 121 North River Drive
> Narragansett, RI 02882
>
> California office
> (408) 884-3985 Business
> (707) 780-1951 Fax
>
> Main office
> (401) 284-1827 Business
> (401) 284-1840 Fax
>
> Oregon office
> (503) 430-1065 Business
> (503) 430-1285 Fax
>
> http://www.teraspeed.com
> This e-mail contains proprietary and confidential intellectual
> property of Teraspeed Consulting Group LLC
> ------------------------------------------------------------------------------------------------------
> Teraspeed(R) is the registered service mark of Teraspeed Consulting
> Group LLC
>
>
>
> ------------------------------------------------------------------------
> Building a website is a piece of cake.
> Yahoo! Small Business gives you all the tools to get online.
> <http://us.rd.yahoo.com/evt=48251/*http://smallbusiness.yahoo.com/webhosting/?p=PASSPORTPLUS>
--
Steve Weir
Teraspeed Consulting Group LLC
121 North River Drive
Narragansett, RI 02882
California office
(408) 884-3985 Business
(707) 780-1951 Fax
Main office
(401) 284-1827 Business
(401) 284-1840 Fax
Oregon office
(503) 430-1065 Business
(503) 430-1285 Fax
http://www.teraspeed.com
This e-mail contains proprietary and confidential intellectual property of
Teraspeed Consulting Group LLC
------------------------------------------------------------------------------------------------------
Teraspeed(R) is the registered service mark of Teraspeed Consulting Group LLC
------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field
or to administer your membership from a web page, go to:
//www.freelists.org/webpage/si-list
For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
List technical documents are available at:
http://www.si-list.net
List archives are viewable at:
//www.freelists.org/archives/si-list
or at our remote archives:
http://groups.yahoo.com/group/si-list/messages
Old (prior to June 6, 2001) list archives are viewable at:
http://www.qsl.net/wb6tpu
Other related posts:
