Thanks, everyone, for the info. I'm surprised and glad to see that
WinSMITH is available again. It was offered first by its publisher,
Noble, then later by the ARRL. I'm quite sure there was a period after
the ARRL dropped it when it wasn't available. There are some things
about it I and others don't like, particularly the 15 step limit to
imported impedance data. But EZNEC currently writes files compatible
with the "current" (1998) version of WinSMITH. It's apparent, though,
that it won't be updated, so it's a good idea to locate a substitute
anyway. I've downloaded the Swiss program and will look over the others
you've been kind enough to recommend. Thanks again.

Roy Lewallen, W7EL