Digital Filter design and simulation programs.   Design code is some public
domain FORTRAN code that I converted to C code.  Simulation code was written
by me.   The program allows one to design a filter and then graph the
calculated response and the simulated response.

Unzip these in separate directories.

The .exe's to run are FIR and IIR.  The filter design is spawned from the 
simulators.

Limitations:  IIR - limited to 4 sections and will crash if you design a  
longer filter;  FIR - limited to 128 constants. The iir program does not 
print out the constants, you'll have to write them down when using 
the 'alter constants' function in the menu. 

