This microcircuit that fits in an aspirin box was published in Radio Electronics magazine in January 1963. The phone has high impedance and the transistors of the time. The power supply consists of a 1.3 V battery.

This microcircuit that fits in an aspirin box was published in Radio Electronics magazine in January 1963. The phone has high impedance and the transistors of the time. The power supply consists of a 1.3 V battery.