Abstract: A microcomputer having a microprocessor operative in response to a dual frequency clock, such microprocessor being adapted to read data stored in a programmable memory in response to address and read enable signals supplied to a programmable memory and being adapted to process such data in response to the clock pulses supplied by the dual frequency clock. The dual frequency clock produces clock pulses at a relatively low rate until such time as either a sensing device is activated or a time duration has passed, in which case the mine is to selfdestruct. When the sensor is activated the microprocessor commands the dual frequency clock to produce relatively high frequency clock pulses to enable the microprocessor to rapidly determine whether the mine should or should not be detonated. Relatively low power is consumed by the microcomputer during the period of time the processor is "counting time" and computing whether the predetermined period of time has arrived, i.e.