I would look into using Compuware's QARUN, it has the capabilities to perform testing of mainframe applications. It works with a 3270 based emulator to provide the ability to test "greeen screens". I haven't used it in a few years but found it at the time to be one of the better tools for testing mainframe based applications.
<BLOCKQUOTE><font size="1" face="Verdana, Arial, Helvetica">quote:</font><HR>Originally posted by jpensyl: My experiences with WinRunner and terminal emulation connections have been very positive - with and without the addins for terminal emulation. The addins do make scripting much easier.<HR></BLOCKQUOTE>
I've also had some great results with WinRunner - specifically with Extra! and Rhumba TE's running apps on both a mainframe and an AS400.