Old Mathcad Worksheets and Mathcad 3.0

Mathcad 15 is needed to convert old files, but you can activate it with your license for Prime. You can download MC15 here: http://www.ptc.com/product/mathcad/free-trial/thank-you

Once you have MC15 installed you could of course just use that version. Prime is still missing a lot of features.

John Bass wrote: I did not know that Mathcad 3.0 will not convert old work sheets to the proper format for Mathcad 3.0. Anyone have any knowledge on how this can be done without having to buy Mathcad 15.0?

You don't have to buy Mathcad 15. If you bought Prime 3 you got it for free (they may not have told you, though). The license file you got for Pime will work for MC15, too. So you have one version to work with (Mathcad 15) and one to shake your head in disbelieve.