Thanks.

I do not know what OSCON has to do with this, because test program (led blink) works, so the program is running without any OSCON-setting. The orinal calibration value is there. The only problem is DS1820 sensor handling. The same read loop (Temp_1) works very well with 16F873 and 16F876A running 4 MHz. The only difference is that I use here GPIO.1 as DQ-pin instead of PortC.0 with those 16F series chips. Maybe I have to try to ask rentron.com, what is wrong with my code with 12F508.