This 1965 circuit uses a Philips 4068 tube to measure extremely small charges. The circuit has as indicator a micro ammeter and the transistors are of the time.
This circuit was found in a General Electric documentation from 1966. It uses discrete components...
The CMOS TLC555 [equivalent to the bipolar 555] can be used as a monostable in the configuration...
This small audio amplifier was found in an American publication in 1975, The integrated circuit used...