Found in a Popular Electronics from the 90s, this game can be seen in other configurations on this site. The circuit uses components that are still common today.
This is the basic operational amplifier configuration for gain 10. R2 can be changed to other...
This circuit was obtained in a 1988 publication, but it can be assembled very easily today, as all...
This circuit was found in a 1966 EEE. Transistors support modern equivalents and the waveforms are...