Digramming tool (but not Dia)?

[uno]

You might take a look at tkgate. It is a digital circuit simulator with
a schematic entry tool. The schematic entry tool could be used for
making diagrams. It is kind of fun to use, but its an older program, so
the UI seems a little dated. You can move things around and the wires
adjust themselves accordingly. The tutorial with the tool is very
handy.

Rotation is a little quirky. You can't rotate an existing gate, but
when you create a new gate, its orientation is determined by a menu
setting.

You can connect wires together. When you draw a wire a the pointer
looks like a soldering iron.

The only output format is a postscript file.


-- 
uno