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Date:      Sun, 28 Oct 2012 11:40:17 -0600
From:      Tom Russo <russo@bogodyn.org>
To:        freebsd-questions@freebsd.org
Cc:        Da Rock <freebsd-questions@herveybayaustralia.com.au>
Subject:   Re: OT: gEDA, SPICE, electronic cad/simulation
Message-ID:  <20121028174017.GB37922@bogodyn.org>
In-Reply-To: <20121028172725.GA37922@bogodyn.org>
References:  <mailman.101.1350302402.57881.freebsd-questions@freebsd.org> <20121028172725.GA37922@bogodyn.org>

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On Sun, Oct 28, 2012 at 11:27:25AM -0600, we recorded a bogon-computron collision of the <russo@bogodyn.org> flavor, containing:
> 
> 3) SPICE (and ng-spice) always uses the first character of a device line to 
>    determine the type of the device.  While most designers will draw a 
>    circuit with an IC in it and give the IC a name like "U1", the character
>    "u" in the first position on a device line means "lossy transmission line"
>    in spice, not "IC."  Thus, in your netlist you're simply telling the 
>    simulator to create a lossy transmission line using nodes "0", "4", "3"
>    and "+9v" as its four ports, and it's getting confused by all the extra
>    parameters on the line.

My mistake.  "U" is the Uniform Lossy RC line, not the lossy transmission line.
The URC device takes 3 nodes and a model name, and so it's used 0, 4, and 3
as the nodes, and then gotten confused about the unknown model named 
"+9v".  It then gets confused about the remaining parameters on the line.

Point remains the same, you can't specify an IC named "U1" in a spice 
netlist by calling the device U1.  You need to use an X subcircuit
instantiation line and an associated .subckt subcircuit definition.

-- 
Tom Russo    KM5VY   SAR502   DM64ux          http://www.swcp.com/~russo/
Tijeras, NM  QRPL#1592 K2#398  SOC#236        http://kevan.org/brain.cgi?DDTNM
"And, isn't sanity really just a one-trick pony anyway? I mean all you get is
 one trick, rational thinking, but when you're good and crazy, oooh, oooh,
 oooh, the sky is the limit!"  --- The Tick




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