Electronics Forum / CAD / August 2008

Does anyone know a trick to make fast random NRZ pulses in LTspice?
I don't want to use the read-from-file option, but would like to
generate them procedurally.
This is for speed and convenience.

What modifications are needed to convert C. Bassos TL431 Pspice model
to a TLVH431 model?
I tried the obvious switching the 2.495V to 1.24V but I get a
reference of 1.49V when I do this, it should be 1.24V.

I draw a transformer simultion with spice. when I chang ratio
from 10:1 to 1:1. I get the model as follow.
.SUBCKT 1TO1  1 2 3 4
VISRC 9 4 DC 0V

can anyone tell me where can i get an online tutorial teaching the
spice modelling syntax or all about modeling using spice? I'm looking
for a reference now.
Thank you.

Is there a data interchange format in the circuit board layout
industry comparable to DXF in the mechanical CAD world?
I use Gnu PCB for my company's designs, but I'm getting into a
collaborative project with another guy who uses Mentor Graphics.  I

Suppose I wanted to add an extra toolbar to an existing program.  Is
there such a piece of software?
                                       ...Jim Thompson