Well this is annoying. I'm using the "FP24.A16" floating point library from AN575. If I try to add 1.0 to 0, I get -1.0. I'm using the same routine for conversion to float on the "1.0" and the "-1.0". It doesn't matter if I put the 1 in AARG and the 0 in BARG or vice-versa. No wonder my PID controller wasn't working right. Has anone else encountered this? Regards, Mark markrages@gmail -- You think that it is a secret, but it never has been one. - fortune cookie -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist