This circuit for multiple sound inputs was found in a Radio Electronics from January 1992. It consists of a Bargraph connected to a multi-input mixer.
March 2017 - Microchip's new 8-bit PIC16F15354 microcontrollers can now be obtained from Mouser...
This signal generator found in Japanese documentation of 1973 uses an unusual integrated circuit...
This circuit that converts very low currents into voltage was obtained in the 80's used component...