So, I suspect that Osuch would be wanting a human readable diff, if I work out how to do this, myself. From the way the code operates, I am gleaning that fractint will already store and interpret zero in a scalemap (as the reference frequency; Another Ay). It will even save zero to parameter files. It won't, however, load zeros from a parameter file. Instead, it interprets them as 1/2/3... If I do this, then Bill Jemison also wants it to display "off" for zero. I could probably get away with putting "Zero means off" in the instructions on the scalemapping screen; F7, and I will see how hard it is to print a string on a condition. In other words, I think a zero should be in parameter files, with a meaning that it does not hav as an exponent in equal temperament; frequency = reference / 2 ^ (1/12) ^ key.