InverseZ92 v1.0.3 (Inverse Z-transform) by Lars Frederiksen (lars@post8.tele.dk) Unfortunately, this good program has vanished from the Internet, including TI's archives. All I had was this function without its documentation, so I am making it available. Hopefully, it will help out some people. Syntax: iztrans(expression,variable) Examples: iztrans(x^a,x) [note that the variable 'n' is reserved by the program for the transformed variable] iztrans(x*(x+1)/(x^2+2x+1),x) iztrans(z/(z-a),z) If you have or find a more recent version of this program or its documentation, please send it to me at bbhatt1@towson.edu Thanks. Bhuvanesh.