PocketMatrix

Google is a wonderful thing.

http://www.google.com/search?hl=en&lr=& ... +emulation

Try this:
http://www.mochasoft.dk/tn5250ce.htm

or this:
http://www.ppc4all.com/appdetail.php?id=1129

or this:
http://www.ericom.com/ptce.asp

I've not tried any of these.