Mechanisms which rotate semiconductor substrates while immersed in wet chemicals are often complex due to a need to prevent leakage of the chemicals. Further, the user’s data is made available to the user from any machine and location by holding the keys necessary for the encryption and decryption of the data at a designated keyholder location that the user has access to. A metering unit is triggered by a control andor regulating unit and meters the fuel quantity traveling into the inlet of the second fuel pump. A second transistor is coupled between the output of the second inverter and ground potential, the second transistor having a gate coupled to an inverse of the input signal operable at the second voltage, wherein a terminal of the second transistor delivers an output signal operable at the first voltage level and corresponding to the same logic state as the input signal. Lastly, the predicted drilling mechanics include at least one of bit wear, mechanical efficiency, power, and operating parameters.