three-state outputs

[Tuukka Toivonen]

Hello. I'm new to VLSI designing, and I'm trying to learn with Electric. I
just installed 6.03 with lesstif-0.92.29. I'm doing mainly digital
schematics for now.

The main problem right now is that I can't seem to be able to create ports
with output pin with three states: on, off and floating. The component
that should do that is "transmission gate" but I couldn't find one from
the component menu.

I tried to built one from transistors (looking a model from a book), in
analog schematics, but it didn't seem to work.

One idea would be to use MUX and add two input wires to it (besides
control line), of which another is input data and another is floating.
Unfortunately, I can not use it because the simulator says:
        "ERROR: Model 'MUX2' not found, simulation aborted"
Can't muxes be used if simulation is wanted?

First I thought that the third pin in a buffer/inverter would do that but
it doesn't seem to do anything at all. What it is used for?