Topband: DX-Edge

[Charles Bibb]

Hi, Topbanders,

Could someone please direct me to where I can obtain software (purchase or 
free, doesn't matter) for my PC that will do the same thing as my old 
plastic (and very worn out) DX-Edge?

I want something that is completely internal to my computer and doesn't 
rely on a web connection.

Charles,
K5ZK

P.S. - Is the plastic slide-rule version still being made?  If so, from 
whom would I order one?