I’m trying to create a De Morgan representation for the 74LS74. I go into the symbol editor, call up the 74LS74, click on “Edit symbol properties”, check the “Has alternate symbol (DeMorgan)” box, click OK, answer YES to the question, but then what? The “Show as DeMorgan…” buttons at the top are still disabled and if I again click on “Edit symbol properties” the “Has alternate symbol (DeMorgan)” box is now unchecked. But if I call up 74LS00, which already has a De Morgan representation, the “Show as DeMorgan” buttons are enabled and you can switch back and forth between the AND and OR representations.
Any ideas what I’m doing wrong? There is mention of De Morgan in the manual, but it is pretty opaque and doesn’t actually explain HOW to get the other representation.